EP4183024A1 - Flow density fluid displacement to store or generate power - Google Patents

Flow density fluid displacement to store or generate power

Info

Publication number
EP4183024A1
EP4183024A1 EP21842806.8A EP21842806A EP4183024A1 EP 4183024 A1 EP4183024 A1 EP 4183024A1 EP 21842806 A EP21842806 A EP 21842806A EP 4183024 A1 EP4183024 A1 EP 4183024A1
Authority
EP
European Patent Office
Prior art keywords
reservoir
water
storage
low density
liquid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP21842806.8A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP4183024A4 (en
Inventor
Ethan J. Novek
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Innovator Energy LLC
Original Assignee
Innovator Energy LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US16/932,429 external-priority patent/US10961975B2/en
Priority claimed from US17/214,100 external-priority patent/US11286898B2/en
Application filed by Innovator Energy LLC filed Critical Innovator Energy LLC
Publication of EP4183024A1 publication Critical patent/EP4183024A1/en
Publication of EP4183024A4 publication Critical patent/EP4183024A4/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03B—MACHINES OR ENGINES FOR LIQUIDS
    • F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
    • F03B13/06—Stations or aggregates of water-storage type, e.g. comprising a turbine and a pump
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B9/00—Water-power plants; Layout, construction or equipment, methods of, or apparatus for, making same
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03B—MACHINES OR ENGINES FOR LIQUIDS
    • F03B13/00—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates
    • F03B13/12—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy
    • F03B13/26—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy using tide energy
    • F03B13/266—Adaptations of machines or engines for special use; Combinations of machines or engines with driving or driven apparatus; Power stations or aggregates characterised by using wave or tide energy using tide energy to compress air
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J15/00—Systems for storing electric energy
    • H02J15/003—Systems for storing electric energy in the form of hydraulic energy
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00—Components
    • F05B2240/90—Mounting on supporting structures or systems
    • F05B2240/93—Mounting on supporting structures or systems on a structure floating on a liquid surface
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00—Components
    • F05B2240/90—Mounting on supporting structures or systems
    • F05B2240/97—Mounting on supporting structures or systems on a submerged structure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2260/00—Function
    • F05B2260/42—Storage of energy
    • F05B2260/422—Storage of energy in the form of potential energy, e.g. pressurized or pumped fluid
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/20—Hydro energy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/30—Energy from the sea, e.g. using wave energy or salinity gradient
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin

Definitions

  • 80% solar and wind energy penetration may be feasible in the United States with 12 hour duration electricity storage. Notably, 100% solar and wind energy penetration is only feasible with at least 3 weeks of electricity storage duration due to the tendency for wind and / or solar to produce at less than predicted rates at least once a year and / or due to seasonal changes in the solar and / or wind energy.
  • Prior art energy storage technologies are too expensive and / or geographically limited to satisfy the multiple terawatt hours of long duration electricity storage required for a high penetration of solar and wind power generation globally.
  • LCOE levelized cost of electricity
  • LCOS levelized cost of storage
  • Energy storage customers such as project developers, electric power utilities, and other customers, generally employ levelized cost as their primary metric for comparing electricity storage technologies, wherein the lower levelized cost, the more economically desirable the electricity storage technology is relative to other options.
  • Levelized cost calculations may include values of including, but are not limited to, one or more or a combination of the following variables: capital cost, or cost of capital, or discount rate, or capacity utilization, or round-trip energy efficiency, or cost of land, or rate of power capacity degradation, or rate of energy storage capacity degradation, or balance of plant, or land use, or geographic limitation, or end-of-life costs, or cost per MW power capacity, or cost per MWh electricity storage capacity.
  • Prior art electricity storage technologies generally have high levelized cost due deficiencies in one or more or a combination of the previous described variables.
  • lithium ion batteries have a high capital cost, significant power capacity degradation, significant energy capacity degradation, land use, and high end-of-life costs.
  • compressed air energy storage has low round trip energy efficiency and geographic limitations.
  • pumped hydro has high land use and geographic limitations.
  • hydrogen electricity storage has low round trip energy efficiency, high cost per MW power capacity, and high rate of power capacity degradation.
  • Other factors may include, but are not limited to, one or more or a combination of the following: environmental impact of manufacturing, environmental impact of land use, material constraints, end-of-life disposal, recyclability, labor use, local labor content, local economic impact, and required maintenance.
  • lithium ion batteries suffer from the following deficiencies relating to the above factors: o Negative environmental impact of manufacturing, including the manufacturing of the material inputs o Material constraints of lithium, cobalt, nickel, and graphite o Short lifespan and end of life disposal challenges o Lithium ion batteries are currently not recyclable o Local labor content is generally minimal, especially for the high cost material inputs, including lithium, nickel, and cobalt o Unethical labor practices and downstream environmental impacts, especially in the mining and refining of the required metals and materials, including cobalt and graphite o The local job creation and related economic impact is minimal because the most of the cost and labor occurs in large manufacturing and mining operations generally located far from the renewable energy project or energy storage project site.
  • Seismic risk and landslide risk including the risk of significant economic and / or human tragedy in the event to a significant earthquake, or landslide slide, or both.
  • renewable energy project developers have become increasingly interested in the development of renewable energy projects offshore, in the ocean and other large water bodies.
  • the visual impacts of near shore offshore wind farms have also encouraged project developers to look increasingly further offshore and into deeper water.
  • the present invention relates to systems and methods for energy storage, or energy generation, or combinations thereof.
  • Some embodiments may be applicable to, for example, an energy storage device. Some embodiments may involve a storage region beneath the surface of a water or liquid body and a storage region near the surface or above a water or liquid body. To ‘charge’ said energy storage device, low density fluid, such as a relatively lower density liquid or a gas, may be pumped into said storage region, displacing a higher density fluid, such as water. To discharge said energy storage device, said higher density fluid may be allowed to displace said lower density fluid, generating electricity due to the flow of the lower density fluid through an electric generator. [0011] Some embodiments may solve one or more or all the deficiencies of prior art energy storage systems. For example, some embodiments possess one or more or a combination of the following:
  • High round trip efficiency such as a round trip efficiency greater than or equal to one or more or a combination of the following: 60%, or 65%, or 70%, or 75%, or 80%, or 85%, or 90%, or 95%, or 99%
  • Some embodiments may be applicable to a system which provides high round trip efficiency electricity storage, and, when needed, can supply fuel and / or electricity for days, or weeks, or months, or years, or any combination thereof.
  • some embodiments may store energy by displacing high density liquid with a low density liquid, wherein the low density liquid or high density liquid or both may comprise a chemical which may alternatively be employed as a fuel.
  • some embodiments may involve storing electricity by displacing a high density liquid with a low density liquid, wherein said displacing energy storage mechanism may store sufficient energy to provide power at maximum system power capacity for greater than or equal to 1 hours, or 2 hours, or 4 hours, or 6 hours, or 8 hours, or 10 hours, or 12 hours, or 14 hours, or 16 hours, or 18 hours, or 20 hours, or 25 hours, or 30 hours or 35 hours, or 40 hours, or 45 hours, or 50 hours, or 75 hours, or 100 hours or any combination thereof.
  • some embodiments may involve storing electricity by displacing a high density liquid with a low density liquid, wherein said displacing energy storage mechanism may store sufficient energy to provide power at maximum system power capacity for less than 50 hours, and wherein the low density liquid, or high density liquid, or both may comprise a fuel and may be capable of providing power for greater than 50 hours, or greater than 75 hours, or greater than 100 hours, or greater than 1 week, or greater than 1 month, if needed.
  • some embodiments may involve storing electricity by displacing a high density liquid with a low density liquid, wherein said displacing energy storage mechanism may store sufficient energy to provide power at maximum system power capacity for a first duration, and wherein the low density liquid, or high density liquid, or both may comprise a fuel and may be capable of providing power for a second duration, when needed.
  • some embodiments may involve storing electricity by displacing a high density liquid with a low density liquid, wherein said displacing energy storage mechanism may store sufficient energy to provide power at maximum system power capacity for a first duration, and wherein the low density liquid, or high density liquid, or both may comprise a fuel and may be capable of providing power for a second duration, when needed, and wherein the said second duration is greater than said first duration.
  • Some embodiments may be applicable to ensuring an underwater tank is in pressure equilibrium with the ocean water adjacent to, or surrounding, or at the same elevation as said underwater tank. Some embodiments may be applicable to minimizing the pressure difference between pressure of a fluid inside an underwater tank and the pressure of water or other fluid outside, or adjacent to, or surrounding, or at the same elevation as said underwater tank. For example, some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from one fluid and transfer said excess pressure or power to another fluid. For example, some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a lower density fluid and transfer said excess pressure or power to a higher density fluid.
  • some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a higher density fluid and transfer said excess pressure or power to a lower density fluid.
  • some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a higher density fluid and transfer said excess pressure or power to a lower density fluid.
  • some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a higher pressure fluid and transfer said excess pressure or power to a lower pressure fluid.
  • some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a higher pressure fluid and transfer said excess pressure or power to a lower pressure fluid, wherein said excess pressure may be less than or equal to the difference in pressure between said higher pressure fluid and water adjacent to, or surrounding, or outside of, or at the same elevation as at least a portion of the underwater tank.
  • some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a first fluid and transfer said excess pressure or power to a second fluid, wherein said excess pressure may be less than or equal to the difference in pressure between said first fluid and water or other fluid adj acent to, or surrounding, or outside of, or at the same elevation as at least a portion of the underwater tank.
  • some embodiments may relate to the use of a pressure exchanger or power exchanger to extract excess pressure or power from a second fluid and transfer said excess pressure or power to a first fluid, wherein said excess pressure may be less than or equal to the difference in pressure between said second fluid and water or other fluid adjacent to, or surrounding, or outside of, or at the same elevation as at least a portion of the underwater tank.
  • some embodiments may relate to pressure equalizers to enable or ensure pressure equilibrium with water or other fluid adjacent to, or surrounding, or outside of, or at the same elevation as at least a portion of the underwater tank.
  • some embodiments may relate to pressure sensors, or valves, or any combination thereof.
  • some embodiments may relate to systems and methods for minimizing or preventing hydraulic ram or minimizing or preventing potential negative impacts of hydraulic ram.
  • Some embodiments may involve energy storage systems wherein the higher density liquid has a density greater than water or ocean water.
  • Some embodiments may involve energy storage systems wherein at least one reservoir is located at an elevation greater than the elevation of the surface of a water body, or sea level, or both.
  • Some embodiments may be applicable to energy storage systems wherein the lower density liquid, or higher density liquid, or both are volatile or have a low boiling point.
  • some embodiments may be applicable to using a pressurized tank or a tank resilient to a pressure difference.
  • some embodiments may be applicable to locating a tank at a water depth or hydrostatic pressure wherein the pressure difference between pressurized fluids inside a tank and the fluids outside or surrounding or adjacent to said tank is less than if said tank was on land, or surrounded by atmospheric pressure, or both.
  • some embodiments may be applicable to refrigerating, or semi-refrigerating, or cooling, or passively cooling, or actively cooling, or thermally managing, or any combination thereof lower density liquid, or higher density liquid or both.
  • some embodiments may relate to ensuring the low density liquid, or high density liquid, or both are stored at a liquid state.
  • some embodiments may relate to ensuring the low density liquid, or high density liquid, or both are stored at a liquid, or supercritical, or slurry, or any combination thereof state.
  • some embodiments may relate to systems and methods for heat exchanging and / or thermal storage to minimize energy use and / or maximize energy efficiency and / or practicality of refrigerating, or semi-refrigerating, or cooling, or passively cooling, or actively cooling, or thermally managing, or any combination thereof lower density liquid and / or higher density liquid.
  • some embodiments may be applicable to enabling the use of cryogenic liquids.
  • some embodiments may be applicable to enabling the simultaneous storage of energy and the generation of power from ocean thermal energy conversion or from temperature differences in the thermocline of an ocean, or water body, or temperature differences between air and water, or any combination thereof.
  • Some embodiments may pertain to tanks applicable to storing low density fluids underwater.
  • some embodiments may relate to rigid or flexible structures.
  • some embodiments may relate to tanks or storage regions containing a porous solid medium, wherein a low density fluid may be stored in the pores of said porous medium.
  • some embodiments may relate to tanks or storage regions containing a porous solid medium, wherein low density fluid is stored in said porous medium by pumping or otherwise directing a low density fluid into said porous medium to displace a higher density fluid stored in said porous medium.
  • some embodiments may employ a storage reservoir comprising a porous medium, wherein the density or weight of said porous medium may reduce the buoyancy of said storage reservoir.
  • some embodiments may employ a storage reservoir comprising a porous medium, wherein the presence of a solid porous medium prevents the substantial collapse of said reservoir if, for example, the pressure inside the reservoir is less than the pressure outside, or adjacent to, or surrounding, or at the same elevation as said reservoir.
  • some embodiments may employ a storage reservoir comprising a porous medium, wherein the presence of a solid porous medium prevents the substantial collapse of said reservoir if, for example, a fluid is pumped out of or removed from a storage reservoir at a greater volumetric rate than fluid is added to or pumped into a storage reservoir.
  • some embodiments may employ a storage reservoir comprising a porous medium, wherein the presence of a solid porous medium prevents the substantial collapse of said reservoir if, for example, a fluid is pumped out of or removed from a storage reservoir without the simultaneous additional of another fluid to said reservoir.
  • Substantial collapse may comprise a storage reservoir decreasing in total volume by greater than or equal to, one or more or a combination of the following: 1 percent, or 5 percent, or 10 percent, or 15 percent, or 20 percent, or 25 percent, or 30 percent, or 35 percent, or 40 percent, or 45 percent, or 50 percent, or 55 percent, or 60 percent, or 65 percent, or 70 percent, or 75 percent, or 80 percent, or 85 percent, or 90 percent, or 95 percent
  • Some embodiments may be applicable to a simultaneous energy storage system and tidal power system. For example, some embodiments may enable the storage of electricity, while also generating power from changes in water level due to tides in the same system. Some embodiments may be applicable to, for example, a tidal power energy generation system, which generates energy from change in water level due to, for example, tides. Some embodiments may involve using the displacement of air or other fluid from a storage region due to a rise in water level due to tides to generate energy, such as electricity. Some embodiments may involve using the movement of air or other fluid into a storage region due to a decrease in water level due to tides to generate electricity. Moving parts for said tidal power system, such as pumps and generators, if desired, may be located entirely above the surface of a water or liquid body.
  • Some embodiments may be applicable to, for example, inhibiting or preventing growth formation or fouling of structures in liquid environments on marine structures, which may include, but are not limited to, marine structures designed for the storage of energy, or generation of tidal power, or combinations thereof. Some embodiments may be applicable to, for example, inhibiting or preventing growth formation or fouling of structures in liquid environments. Said liquid environments may comprise aqueous and / or non-aqueous environments. Some embodiments described herein may inhibit or eliminate or prevent growth formation or fouling without the need for coatings, paint, manual cleaning/scrubbing, or other methods described in the art.
  • Growth formations may include, but are not limited to, one or more or a combination of the following: marine growths, foulants, marine creatures, marine animals, inorganic scaling, organic scaling, barnacles, mussels, clams, oysters, worms, shrimp, crustaceans, biofilms, algae, bacteria, fungi, or ameba.
  • Moving parts for said embodiments related to inhibiting or preventing growth formation or fouling or corrosion of structures in liquid environments, such as pumps and generators, if desired, may be located entirely above the surface of a water or liquid body.
  • Some embodiments may be applicable to, for example, increasing or decreasing the height of a floating structure, such as a dock.
  • Some embodiments described herein may involve increasing the height of a floating structure above the surface of a liquid by pumping air into a concave region within or beneath said floating structure such that the air or other gas or other low-density fluid at least partially displaces a portion of water in said concave region.
  • the height of a floating structure above the surface of a liquid may be decreased by allowing gas to escape from or by pumping gas out of said concave region.
  • Air or other gas may be transferred in or out of said concave region using one or more tubes.
  • the concave region may be open to the water or other liquid.
  • the pumping or release of gas may be conducted using moving parts entirely outside of the water or liquid body.
  • the moving parts e.g. air pump
  • the moving parts may comprise lower cost equipment, may be less susceptible to fouling, and may have a longer lifespan.
  • Figure 1 An example structure with a concave region ‘gas pocket’ (‘3’) on the bottom of each float or pontoon.
  • Figure 2 (above): An example structure with a concave region ‘gas pocket’ (‘3’) on the bottom of each float or pontoon with air pump and tube interconnected.
  • Figure 3 An example embodiment with extended ‘walls’, which may be employed to prevent air or gas losses in the event of, for example, waves, turbulent water, or a significant change in the angle of the dock.
  • Figure 4 An example embodiment where changing the volume of gas in a gas pocket adjusts the height above the liquid surface and/or angle of a floating structure, such as a dock. Figure 4 may show height increasing.
  • Figure 5 An example embodiment where changing the volume of gas in a gas pocket adjusts the height above the liquid surface and/or angle of a floating structure, such as a dock. Figure 5 may show height decreasing.
  • Figure 6 An example simplified setup of an embodiment employing a lower density liquid and a higher density liquid.
  • Figure 7 Step 1: Figure 7 may show an energy storage embodiment undergoing charging.
  • Figure 8 Step 2: Figure 8 may show an energy storage embodiment at a relatively charged state.
  • Figure 9 Step 3: Figure 9 may show an energy storage embodiment discharging.
  • Figure 10 Step 4: Figure 10 may show an energy storage embodiment at a relatively discharged state.
  • Figure 11 may show an example embodiment where the LDL and/or HDL storage regions at a higher head height or above the surface are located on a platform or a floating platform.
  • Figure 12 may show an example embodiment where the LDL and/or HDL storage regions at a higher head height or above the surface are located on land.
  • Figure 13 may show an example embodiment where multiple subsurface storage regions are employed for energy storage and / or chemical storage.
  • Figure 14 Step 1 Figure 14 may show an embodiment where electricity is being generated.
  • Figure 15 Step 2 Figure 15 may show an embodiment where the storage region is nearly full with water.
  • Figure 16 may show an embodiment generating electricity when the surrounding water body water level is relatively low compared to the water level inside the storage region.
  • Figure 17 Step 4 Figure 17 may show an embodiment where the storage region is nearly empty with water.
  • Figure 18 may show an embodiment where the storage region is fully empty with water.
  • Figure 19 Step 5 (Lower Tide, Pump remaining water out): Figure 19 may show an embodiment where air is pumped into a storage region to remove or displace residual water.
  • Figure 20 Step 1 (Higher Tide, Filling, Electricity Generation): Figure 20 shows an example embodiment where water / air cavity or storage region contains a porous material.
  • Figure 21 shows an example embodiment where water / air cavity or storage region contains a porous material.
  • Figure 22 Step 3 (Lower Tide, Emptying, Generating Electricity): Figure 22 shows an example embodiment where water / air cavity or storage region contains a porous material.
  • Figure 23 Step 4 (Lower Tide, Empty): Figure 23 shows an example embodiment where water air cavity or storage region contains a porous material.
  • Figure 24 shows an example embodiment where water / air cavity or storage region is located on or within a water body.
  • Figure 25 shows an example embodiment where water / air cavity or storage region is located on or within a water body.
  • Figure 26 shows an example embodiment where water / air cavity or storage region is located on or within a water body.
  • Figure 27 Alternative Step 3 (Lower Tide, Emptying, Depending on Tide and Location): Figure 27 shows an example embodiment where water / air cavity or storage region is located on or within a water body.
  • Figure 28 shows an example embodiment where water / air cavity or storage region is located on or within a water body.
  • Figure 29 shows an example embodiment with a floating pump or generator station.
  • Figure 30 shows an energy storage system where the first storage reservoir is located on land and the pump and / or generator is located on land.
  • Figure 31 shows an energy storage system where the first storage reservoir is located on land and the pump and / or generator is located on land.
  • Figure 32 shows an energy storage system where the first storage reservoir is located near, at, or beneath the surface of a water body and/or the pump and / or generator is located near, at or beneath the surface of a water body.
  • Figure 33 shows an energy storage system where the first storage reservoir is located near, at, or beneath the surface of a water body and/or the pump and / or generator is located near, at or beneath the surface of a water body.
  • Figure 34 is an embodiment of low density fluid displacement.
  • Figure 35 is an embodiment of low density fluid displacement.
  • Figure 36 is an embodiment of low density fluid displacement.
  • Figure 37 is an embodiment of low density fluid displacement.
  • Figure 38 is an embodiment of low density fluid displacement.
  • Figure 39 is an embodiment of low density fluid displacement.
  • Figure 40 is an embodiment of low density fluid displacement.
  • Figure 41 is an embodiment of low density fluid displacement.
  • Figure 42 is an embodiment of low density fluid displacement.
  • Figure 43 is an embodiment of low density fluid displacement.
  • Figure 44 is an embodiment of low density fluid displacement.
  • Figure 45 is an embodiment of low density fluid displacement.
  • Figure 46 is an embodiment of low density fluid displacement.
  • Figure 47 is an embodiment of low density fluid displacement.
  • Figure 48 is an embodiment of low density fluid displacement.
  • Figure 49 is an embodiment of low density fluid displacement.
  • Figure 50 is an embodiment of low density fluid displacement.
  • Figure 51 is an embodiment of low density fluid displacement.
  • Figure 52 is an embodiment of low density fluid displacement.
  • Figure 53 is an embodiment of low density fluid displacement.
  • Figure 54 is an embodiment of low density fluid displacement.
  • Figure 55 is an embodiment of low density fluid displacement.
  • Figure 56 is an embodiment of low density fluid displacement.
  • Figure 57 is an embodiment of low density fluid displacement.
  • Figure 58 is an embodiment of low density fluid displacement.
  • Figure 59 is an embodiment of low density fluid displacement.
  • Figure 60 is an embodiment of low density fluid displacement.
  • Figure 61 is an embodiment of low density fluid displacement.
  • Figure 62 is an embodiment of low density fluid displacement.
  • Figure 63 is an embodiment of low density fluid displacement.
  • Figure 64 is an embodiment of low density fluid displacement.
  • Figure 65 is an embodiment of low density fluid displacement.
  • Figure 66 is an embodiment of low density fluid displacement.
  • Figure 67 is an embodiment of low density fluid displacement.
  • Figure 68 is an embodiment of low density fluid displacement.
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  • Figure 70 is an embodiment of low density fluid displacement.
  • Figure 71 is an embodiment of low density fluid displacement.
  • Figure 72 is an embodiment of low density fluid displacement.
  • Figure 73 is an embodiment of low density fluid displacement.
  • Figure 74 is an embodiment of low density fluid displacement.
  • Figure 75 is an embodiment of low density fluid displacement.
  • Figure 76 is an embodiment of low density fluid displacement.
  • Figure 77 is an embodiment of low density fluid displacement.
  • Figure 78 is an embodiment of low density fluid displacement.
  • Figure 79 is an embodiment of low density fluid displacement.
  • Figure 80 is an embodiment of low density fluid displacement.
  • Figure 81 is an embodiment of low density fluid displacement.
  • Figure 82 is an embodiment of low density fluid displacement.
  • Figure 83 is an embodiment of low density fluid displacement.
  • Figure 84 is an embodiment of low density fluid displacement.
  • Figure 85 is an embodiment of low density fluid displacement.
  • Figure 86 is an embodiment of low density fluid displacement.
  • Figure 87 is an embodiment of low density fluid displacement.
  • Figure 88 A process for energy storage storing electricity by displacing a high density liquid with a low density liquid and employing cold and warm supplemental thermal storage.
  • Figure 89 A process for energy storage generating electricity by displacing a low density liquid with a high density liquid and employing cold and warm supplemental thermal storage.
  • Figure 90 A process for energy storage storing electricity by displacing a high density liquid with a low density liquid and employing cold and warm supplemental thermal storage and a cooling system.
  • Figure 91 A process for energy storage generating electricity by displacing a low density liquid with a high density liquid and employing cold and warm supplemental thermal storage and a cooling system.
  • Figure 92 A process for energy storage storing electricity by displacing a high density liquid with a low density liquid and employing thermal storage and a cooling system.
  • Figure 93 A process for energy storage generating electricity by displacing a low density liquid with a high density liquid and employing thermal storage and a cooling system.
  • Figure 94 A process for energy storage storing electricity by displacing a high density liquid with a low density liquid and employing thermal storage and a cooling system.
  • Figure 95 A process for energy storage generating electricity by displacing a low density liquid with a high density liquid and employing thermal storage and a cooling system.
  • Figure 96 A process for energy storage storing electricity by displacing a high density liquid with a low density liquid and employing thermal storage and a cooling system
  • Figure 97 A process for energy storage generating electricity by displacing a low density liquid with a high density liquid and employing thermal storage and a cooling system.
  • Figure 98 A process for energy storage generating electricity by displacing a low density liquid with a high density liquid and employing thermal storage and a cooling system.
  • Figure 99 A process for energy storage storing electricity by displacing a high density liquid with a low density liquid and employing thermal storage and a cooling system
  • Figure 100 A process for energy storage with the higher elevation reservoir located on land and the lower elevation reservoir located underwater.
  • Figure 101 A process for energy storage with the higher elevation reservoir located on land and the lower elevation reservoir located underwater.
  • Figure 102 A process for energy storage with the higher elevation reservoir located underwater near or on a seabed and the lower elevation reservoir located underwater near or on a seafloor.
  • Figure 103 A process for energy storage with the higher elevation reservoir located underwater near or on a seabed and the lower elevation reservoir located underwater near or on a seafloor.
  • Figure 104 A process for energy storage with the higher elevation reservoir located on the water as a semi-submersible or fully submersed or combination thereof vessel and the lower elevation reservoir located underwater near or on a seafloor.
  • Figure 105 A process for energy storage with the higher elevation reservoir located on the water as a semi-submersible or fully submersed or combination thereof vessel and the lower elevation reservoir located underwater near or on a seafloor.
  • Figure 106 A process for energy storage with the higher elevation reservoir comprising a floating vessel and the lower elevation reservoir located under water near or on the seafloor.
  • Figure 107 A process for energy storage with the higher elevation reservoir comprising a floating vessel and the lower elevation reservoir located under water near or on the seafloor.
  • Figure 108 A process for energy storage with a lower elevation reservoir underwater and / or above and / or on the seafloor.
  • Figure 109 A process for energy storage with a lower elevation reservoir underwater and / or above and / or on the seafloor.
  • Figure 110 A process for energy storage with a lower elevation reservoir underwater and / or above and / or on the seafloor.
  • Figure 111 A process for energy storage with a lower elevation reservoir underwater and / or above and / or on the seafloor.
  • Figure 112 A process for energy storage with a lower elevation reservoir underwater and / or underground beneath the seafloor or buried or a combination thereof.
  • Figure 113 A process for energy storage with a lower elevation reservoir underwater and / or underground beneath the seafloor or buried or a combination thereof.
  • Figure 114 A process for energy storage with a lower elevation reservoir underwater and / or underground beneath the seafloor or buried or a combination thereof.
  • Figure 115 A process for energy storage with a lower elevation reservoir underwater and / or underground beneath the seafloor or buried or a combination thereof.
  • Figure 116 A process for energy storage with a lower elevation reservoir underground.
  • Figure 117 A process for energy storage with a lower elevation reservoir underground.
  • Figure 118 A process for energy storage with a lower elevation reservoir underground.
  • Figure 119 A process for energy storage with a lower elevation reservoir underground.
  • Figure 120 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir.
  • Figure 121 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir.
  • Figure 122 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir.
  • Figure 123 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir.’
  • Figure 124 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and wherein the higher elevation reservoir is a floating structure.
  • Figure 125 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and wherein the higher elevation reservoir is a floating structure.
  • Figure 126 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and wherein the higher elevation reservoir is a floating structure.
  • Figure 127 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and wherein the higher elevation reservoir is a floating structure.
  • Figure 128 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage.
  • Figure 129 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage.
  • Figure 130 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage.
  • Figure 131 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage.
  • Figure 132 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage.
  • Figure 133 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage.
  • Figure 134 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage and a thermal management system.
  • Figure 135 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs thermal storage and a thermal management system.
  • Figure 136 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir with example flow rates.
  • Figure 137 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir with example flow rates.
  • Figure 138 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs cooling from cooling water or ocean water or deep ocean water.
  • Figure 139 A process for energy storage which is configured to store both low density liquid and high density liquid in a higher elevation reservoir and employs cooling from cooling water or ocean water or deep ocean water.
  • Figure 140A A process for energy storage with a pressure exchanger with thermal management, or cooling, or refrigeration.
  • Figure 140B A process for energy storage with a pressure exchanger with thermal management, or cooling, or refrigeration.
  • Figure 140C A process for energy storage with a pressure exchanger without thermal management, or cooling, or refrigeration.
  • Figure 141A A process for energy storage with a pressure exchanger with thermal management, or cooling, or refrigeration.
  • Figure 141B A process for energy storage with a pressure exchanger with thermal management, or cooling, or refrigeration.
  • Figure 141C A process for energy storage with a pressure exchanger without thermal management, or cooling, or refrigeration.
  • Figure 142A A process for energy storage with a pressure exchanger housed in one unit with thermal management, or cooling, or refrigeration.
  • Figure 142B A process for energy storage with a pressure exchanger housed in one unit without thermal management, or cooling, or refrigeration.
  • Figure 143A A process for energy storage with a pressure exchanger housed in one unit with thermal management, or cooling, or refrigeration.
  • Figure 143B A process for energy storage with a pressure exchanger housed in one unit without thermal management, or cooling, or refrigeration.
  • Figure 144 A process for energy storage employing a mechanism to remove or separate a portion of low density liquid present in the high density liquid.
  • Figure 145 A process for energy storage with a countercurrent heat exchanger.
  • Figure 146 A process for energy storage with a countercurrent heat exchanger.
  • Figure 147 A process for energy storage with a countercurrent heat exchanger and additional supplemental cooling.
  • Figure 148 A process for energy storage with a first, second and third reservoir, wherein the elevation of the first and third reservoirs are greater than the second reservoir and the elevation of the first reservoir is different from the elevation of the third reservoir.
  • Figure 149 A process for energy storage with a first, second and third reservoir, wherein the elevation of the first and third reservoirs are greater than the second reservoir and the elevation of the first reservoir is different from the elevation of the third reservoir.
  • Figure 150 A process for energy storage with a first, second and third reservoir, wherein the elevation of the first and third reservoirs are greater than the second reservoir and the elevation of the first reservoir is different from the elevation of the third reservoir.
  • Figure 151 A process for energy storage with a first, second and third reservoir, wherein the elevation of the first and third reservoirs are greater than the second reservoir and the elevation of the first reservoir is different from the elevation of the third reservoir.
  • Figure 152 A subsea or underwater or under a body of liquid tank comprising a rigid tank and a pressure equalizer.
  • Figure 153 A subsea or underwater or under a body of liquid tank comprising a rigid tank and a pressure equalizer.
  • Figure 154 A process for energy storage with a pressure exchanger.
  • Figure 155 A process for energy storage with a pressure exchanger.
  • Figure 156 A process for energy storage with a pressure exchanger.
  • Figure 157 A process for energy storage with a pressure exchanger.
  • Figure 158 A process for energy storage with a pump providing supplemental pressure.
  • Figure 159 A process for energy storage with a pump providing supplemental pressure.
  • Figure 160 A process for energy storage with a pressure exchanger.
  • Figure 161 A process for energy storage with a pressure exchanger.
  • Figure 162 A process for energy storage with a pressure exchanger and a second reservoir at a different elevation than a third reservoir.
  • Figure 163 A process for energy storage with a pressure exchanger and a second reservoir at a different elevation than a third reservoir.
  • Figure 164 A process for energy storage with a lower elevation reservoir comprising separate storage for a high density liquid than low density liquid and wherein at least a portion of displacement is provided by a pressure exchanger.
  • Figure 165 A process for energy storage with a lower elevation reservoir comprising separate storage for a high density liquid than low density liquid and wherein at least a portion of displacement is provided by a pressure exchanger.
  • Example Energy Storage Embodiments Overview Introduced are systems, and methods for energy storage and/or simultaneous oil or chemical storage.
  • energy is stored via a hydrostatic pressure difference between one or more insoluble or low solubility fluids, which may be driven by a density difference between the one or more fluids.
  • the technology may employ the depth of water bodies to, for example, enable this hydrostatic pressure.
  • An embodiment may comprise, for example, a relatively high density liquid, and a relatively low density liquid or fluid, which may have a lower density than the relatively high density liquid.
  • the end-to-end technology may be a closed system or may be at least closed beneath the surface of the water body.
  • all or almost all moving parts above the surface of the water body such as ocean or lake, or, advantageously, not have moving parts, or not have essential moving parts or not have relatively costly moving parts, under water or deep under water, or no moving parts at a depth greater than 250 ft under water, or no moving parts at a depth greater than 1000ft under water.
  • the system may be a closed system, wherein the internal fluids, for example high density and low density liquids, are in direct contact with each other.
  • the internal fluids may be separate from or substantially not in contact with the surrounding water body.
  • the water in the water body may simply be employed to ensure pressure, for example liquid pressure, is in equilibrium between the inside fluids and surrounding or external water body.
  • An equilibrium in pressure between the outside and inside of the vessel may enable, for example, the use of lower cost materials, as, for example, at least a portion of the materials may not require resistance to pressure differences or substantial differences.
  • Energy may be stored in the hydrostatic pressure difference between the media (for example: liquids) inside the vessel, for example, wherein one or more media have a higher hydrostatic pressure than another one or more media.
  • Difference in hydrostatic pressure may be driven by the difference in hydrostatic pressure of liquids of difference densities at the same hydraulic head height.
  • An embodiment may comprise media comprising two or more immiscible or low solubility liquids with different densities. The difference in density between two or more liquids at the same or similar height may drive the hydrostatic pressure difference.
  • Embodiments may employ liquids, solids, gases, supercritical fluids or other media phases.
  • One or more phases may be advantageously employed, for example, because said integrated system may be a closed system.
  • contamination with the surrounding water body may not be a challenge, unless, for example, there is a leak.
  • liquid storage of a higher density liquid (such as water) and liquid storage of a lower density liquid (such butane) are placed at a relatively higher head height than a separate liquid-liquid interface vessel or vessels.
  • Said relatively higher head height may be including, but not limited to, one or more of a combination thereof: located lesser depth in the surface of a water body, at the surface of a water body, above the surface of a water body, floating on the surface of a water body, located on land adjacent to a water body, or located on another water body, or located on land. It may be desirable for the higher density liquid to have the same or similar density as the surrounding water body at the same depth.
  • the higher density liquid may comprise a liquid of the same or similar or relatively close density as the surrounding water body or other surrounding media.
  • the higher density liquid may significantly differ in density from the surrounding water body or other surrounding media, as in such an embodiment, pressure difference resistant materials may be required.
  • Separate liquid-liquid interface storage vessel or vessels may be located at a lower head height than the liquid storage. Said liquid-liquid interface storage vessel or vessels may be connected to the higher head height liquid storage vessel or vessels using one or more tubes. Tubes may be employed to transport the lower density liquid or the higher density liquid or a combination thereof.
  • One or more tubes may be connected to one or more valves or pumps or sealed connecting joints.
  • the lower density liquid may be connected to liquid tube or tubes, which may be connected to one or more pumps or generators or connected to low density liquid storage or a combination thereof.
  • the higher density liquid may be connected to liquid tube or tubes, which may be connected to one or more pumps or generators or connected to higher density liquid storage or a combination thereof.
  • Storing energy may involve, for example, pumping the lower density liquid into a tube or tubes, displacing at least a portion of the higher density liquid out of the tube or tubes and underwater vessel or vessels into the higher density liquid storage or, alternatively, displacing the higher density liquid into the surrounding water body.
  • Energy may be stored energy due to the difference in hydrostatic pressure between the low-density liquid and high density liquid at the same hydraulic head height - for example, as the low density is pumped into the tubing or storage vessel, it is overcoming the hydrostatic pressure of the higher density liquid, developing a hydraulic head.
  • a valve may be employed to prevent the one or more liquids from undesirably reversing flow direction.
  • a check valve may be employed during pumping operation to prevent the low-density liquid from reversing pumping direction. Energy storage time-period may indefinite if there are no leaks. During discharge, one or more valves may open, enabling the pressurized low-density liquid to be at least partially displaced and enable said low density liquid to power a generator. Valves, pumps, generators, and other moving parts may be located at the surface or just below the surface, or on land, or a combination thereof as this may reduce capital, operational, and/or maintenance costs.
  • the process may be an open system, wherein the higher density fluid is comprises the fluid in one or more liquid or water bodies, such as, for example, water or salt water or oil or relatively inexpensive liquid.
  • the low density liquid may be pumped into one or more vessels, displacing the higher density water or liquid in the vessel.
  • the process may contaminate the water in the bay, although this may be minimized by, including, but not limited to, minimizing mixing, preventing the contaminant liquid level, for example the low density liquid level, from approaching or surpassing the edge of the vessel, using a low solubility or insoluble combination of liquids or media, using a non-hazardous or inexpensive low density liquid, or a combination thereof.
  • a version of the present embodiment may comprise an upside down barrel with a tube opening on the inside of the closed, upward facing side of the barrel and a port open to the surrounding liquid body (for example, water body or ocean or lake) on the bottom facing side of the barrel.
  • a version of the present embodiment may comprise an upside down barrel with a tube connected to a liquid tight port connected to upward facing side of the barrel and a port open to the surrounding liquid body (for example, water body or ocean or lake) on the bottom facing side of the barrel.
  • a version of the present embodiment may not contain any liquid tight ports - a tube may be fed into the open side of the up-side-down vessel or barrel and attached to the bottom (inside of top of barrel because up-side-down) of the inside of the vessel or barrel.
  • Advantages of said alternative embodiment include, but are not limited to, a simplified construction, higher pressure resistance, lower opportunity for leak or contamination, and low cost.
  • One or more vessels or barrels may be further connected to a weight or anchor and the upper region of the barrel may be connected to floatation to maintain the one or more vessels or barrels in the desired position (for example, the upside-down position).
  • One or more tubes may be further connected to a pump or generator, which may be further, connected to one or more low density fluid storage vessels.
  • Said one or more lower density liquids (or other fluid, such as a gas) storage vessels may be located at a higher head height, for example, near the surface, at the surface, or above the surface of the water body.
  • the lower density liquid (or other fluid, such as a gas) may be pumped into the vessel, displacing the higher density liquid.
  • low density liquid may be pumped into the vessel, displacing the higher density liquid.
  • the pressure of the low density liquid when the liquid is forced to displace higher density liquid may be at a higher pressure than the surrounding water body, wherein the pressure difference between the low density liquid and the surrounding water body increases with decreasing depth. At the interface between the lower and higher density liquids, the pressure of the two liquids may be equal or close to equal. As the depth of the lower density liquid decreases (or the higher the low density liquid is above the liquid-liquid interface), the greater the lower density liquid deviates in pressure from the higher density liquid or the greater the net pressure of the low density liquid.
  • the tube or other vessel transporting the lower density liquid across depths or head heights may require pressure resistance, the pressure resistance requirement may increase with decreasing depth (or greater hydraulic height from the liquid-liquid interface or deepest point).
  • the point of the pump or generation may comprise the highest pressure in the embodiment.
  • One way of describing this phenomenon is: [0198] If an open tube is placed vertically in a water body, the water inside the tube, although separated, is predominately at the same pressure as the surrounding water body at any given depth because the water pressure applied by the water inside the tube above a given point in the tube is the same as the water surrounding the tube.
  • a liquid of different density such as a lower or higher density
  • the pressure of the liquid at any given point may be equivalent to the liquid pressure applied by the liquid above a point in the liquid.
  • a liquid of lower density may have a significantly lower gravitationally derived pressure than a liquid of higher density.
  • P Net may be the Net Pressure of Lower Density Liquid at a Given Height above the Lowest Depth of the Lower Density Liquid or Liquid - Liquid Interface
  • P HD may be the Gravitational Pressure Head of Higher Density Liquid at the Height Above Lowest Depth of Low Density Liquid or Liquid - Liquid Interface
  • P LD may be the Gravitational Pressure Head of Lower Density Liquid at Height Above Lowest Depth of Low Density Liquid or Liquid - Liquid Interface
  • Figure 6 shows a simplified setup of an embodiment employing a lower density liquid and a higher density liquid.
  • the two boxes with black text are the higher head height liquid storage vessels.
  • the higher head height liquid storage region is connected via tubes or pipes to one or more separate storage vessels.
  • the tubes are connected to a single storage vessel at a head height below the surface of the liquid body (such as a water body) and located at a head height below the higher head height liquid storage vessels, which may be referred to as the lower head height storage vessel.
  • the higher density liquid tube or pipe is connected to one or more ports at the bottom of the lower head height storage vessel.
  • the lower density liquid tube or pipe is connected to one or more ports at the top of the lower head height storage vessel.
  • ports on the lower head height storage vessel may not be of importance, and ports may be placed, in, including, but not limited to: next to each other, across from each other vertically, across from each other horizontally, placed randomly, or in another configuration or in a combination thereof. It may be important for the ports to be liquid tight. An exception may be, for example, if the heavy liquid port is open to the surrounding water bay, potentially eliminating the need for a liquid tight port for the higher density liquid and potentially eliminating the need for a high density liquid pipe or storage vessel.
  • the region inside the lower head height vessel where the higher density liquid and lower density liquid meet may be referred to as the fluid-fluid or liquid-liquid interface.
  • the liquids may be contacted directly, in which case it may be desirable for the liquids to be immiscible.
  • the liquids may also be spaced or separated or constitute non-contiguous liquids by a separator or drum, including, but not limited to, a drum or floating drum. If a floating drum is employed to separate the higher density liquid from the lower density liquid, it may be desirable for the floating drum to be of lower density than the higher density liquid and higher density than the lower density liquid.
  • a liquid-liquid separator or drum may be employed, for example, to reduce liquid-liquid mixing (especially important for soluble liquids) or, in the case where open water is the high density liquid higher density liquid, reduce environmental contamination.
  • Energy is storage by pumping the lower density liquid into the lower density liquid tube or pipe, which may displace the higher density liquid from the lower head height storage vessel.
  • Stored energy may be released by enabling the displaced water to enter the lower head height vessel, which may displace the lower head height liquid and generate electricity.
  • the pump / generator is shown connected to the lower density liquid pipe or tube, which may enable higher pumping efficiency. Pump may be above the water surface, enabling no moving parts to be under water.
  • the lower density liquid may be under pressure during charging and discharging.
  • a pump / generator may be connected to the higher density liquid.
  • One potential challenge of pumping the higher density liquid directly is charging may require the formation of a partial vacuum, which may be less efficient and, even in the case of a pure vacuum, may not be enough driving force to remove sufficient higher density liquid from the lower head height vessel. It may be desirable for the pump or generator to be beneath the water line, for example, if the pump or generator is directly in contact or pumping the higher density liquid.
  • Liquid storage regions may comprise tanks or reservoirs storing the lower density liquid or higher density liquid.
  • Substantially immiscible or insoluble may mean a liquid which is less than 50 weight percent (wt%), or less than 40wt%, or less than 30wt%, or less than 20w% soluble in the other liquid.
  • the higher density liquid storage region may be beneath the water line or at the same or similar or lower depth than the liquid-liquid interface or lowest point of the lower density liquid. This may be advantageous, for example, if the higher density liquid has the same density as the liquid body, such as water body, surrounding the energy storage device.
  • the higher density liquid storage region may comprise, for example, a bladder-like storage device in pressure equilibrium with the surrounding liquid body, such as water body.
  • the higher density liquid storage region may comprise, for example, a storage device with a floating or movable roof in pressure equilibrium with the surrounding liquid body, such as water body.
  • the lower head height vessel may be pressure difference resistant.
  • the pressure resistance required by the lower head height vessel may increase with vertical distance from the liquid-liquid interface or lowest point of the lower density liquid. It may be advantageous to minimize the vertical height of the vessel, minimizing the pressure difference experienced by the lower head height vessel compared. This may transition more or most of the lower density liquid pressure difference to the pipe / tube. It may be advantageous to progressively increase the reinforcement of the lower head height vessel with increasing vertical distance from the liquid- liquid interface or the lowest point of the lower density liquid.
  • the structure of progressively increasing the reinforcement of the lower head height vessel may be similar to water towers, wherein the vessel is progressively more pressurize resistant and reinforced with higher hydrostatic pressure.
  • the higher density liquid storage and lower density liquid storage may be, for example, located beneath the surface, floating on the surface, or on land.
  • the higher density liquid storage may comprise the surrounding water body.
  • the higher density liquid storage may be in a different location than the lower density liquid storage.
  • the higher density liquid storage may be a bladder like expandable and contractible volume storage region beneath the water body surface, while the lower density liquid storage region may be located on land.
  • the energy storage device may undergo charging or discharging at any point in storage capacity. For example, if the device is at least a portion charged, it may be discharged. For example, if the device is at least a portion discharged, it may be charged. For example, if the device is fully charged, it may not have the capacity to further charge. For example, if the device is fully discharged, it may not have the capacity to further discharge.
  • Figure 7 may show an energy storage device undergoing charging.
  • a liquid pump may pressurize and pump the Lower Density Liquid (LDL) into a pipe connected to the lower head height storage region, which may allow the LDL to displace the higher density liquid (HDL) in the lower head height storage.
  • LDL Lower Density Liquid
  • HDL higher density liquid
  • FIG 7 HDL may be shown being transferred it to an HDL storage region above the lower head height storage region.
  • the HDL storage region for example, if it comprises a fluid in equilibrium with the hydrostatic pressure of the surrounding liquid or of the same density as the surround liquid, may be located elsewhere, for example, beneath the surface of the liquid body, or at the same height or depth as the lower head region, or below the depth of the liquid-liquid interface.
  • the pump or pumps may be powered by work, for example, electricity, hydraulic pressure, or mechanical work.
  • the LDL may a volatile liquid (such as propane or butane) and the LDL storage region may be closed. Regardless of whether the LDL is volatile, the LDL storage region may be closed to outside air. If the LDL is sufficiently volatile, the headspace gases in the LDL may comprise the LDL in the gas phase. If the LDL has a sufficiently high partial pressure (for example: propane or butane), the LDL storage region may be pressure resistant and comply with the appropriate safety precautions. [0208]
  • the HDL may be a volatile liquid.
  • the HDL may comprise water. It may be desirable for the HDL storage region to not be open outside air, as biofoubng agents and other contaminants may enter. Alternatively, the headspace of the HDL storage region may comprise, for example, filtered or treated air.
  • Figure 8 may show an energy storage device at a relatively charged state. At a charged, or discharge, or when charged, or when at a steady state, a check valve may be employed to prevent liquid from flowing into the LDL tank.
  • LDL may not be advantageous to have LDL enter the higher density liquid region, which may occur, for example, during overcharging if the HDL storage region is located at a higher height relative to the LDL. If this were to occur, for example, the LDL may float to the surface of the HDL storage region if the HDL storage region is at a higher height relative to the LDL liquid- liquid interface. This may be remediated, for example, by removing the LDL from the HDL using, for example, one or more or a combination of the following: decanting, cyclone, coalescer, filter, or other means of phase or liquid-liquid separations.
  • the LDL may be separated by, for example, including, but not limited to, one or more or a combination of the following: removing LDL gas from the headspace, compression of headspace gases, cooling headspace gases, gas separation methods, pressure swing adsorption, pressure swing absorption, membrane, distillation, combustion, absorption, or adsorption.
  • Figure 9 may show an energy storage device discharging.
  • HDL may displace LDL in the subsurface storage region, which may result in high pressure LDL passing through a generator, generating electricity, and entering, for example, an LDL storage tank.
  • Figure 10 may show an energy storage device at a relatively discharged state. At a discharged or charged or when charged or when at a steady state, a check valve may be employed to prevent liquid from flowing into the LDL tank.
  • Figure 11 may show an example embodiment where the LDL and/or HDL storage regions at a higher head height or above the surface are located on a platform or a floating platform. If desired, the only direct interconnected between the energy storage device and land may be a medium for transporting electricity, such as an electric cable.
  • Figure 12 Figure 12 may show an example embodiment where the LDL and/or HDL storage regions at a higher head height or above the surface are located on land, such as on the shore or on an island.
  • Figure 13 Figure 13 may show an example embodiment where multiple subsurface storage regions are employed for energy storage. If there is more than one subsurface storage region, the subsurface storage regions may be interconnected, which may minimize the number of pipes between the higher head height storage region or regions and the lower head height or subsurface storage region or regions.
  • Tubes may be wrapped in a roll or in another storage configuration.
  • the location of the ports may be of importance, and may be located, for example, to minimize mixing. For example, ports may be located near the top of the vessel for the low-density liquid tube connection and near the bottom of the vessel for the higher density liquid tube.
  • Tubes may be connected to one or more rolls of tubing c. Tubes or vessels may require withstanding pressure, although in some embodiments only the tube transporting the lower density liquid must withstand substantial pressure differences.
  • a liquid at the same or similar density as surrounding water body may be salt water or an aqueous solution containing a dense organic additive, such as glycerol or ethylene glycol or propylene glycol. It may be desirable for the liquid to not comprise bio-foulants, scaling agents, or corrosion or degradation causing agents). Alternatively, the liquid may comprise bio-foulants, scaling agents, or corrosion or degradation causing agents, for example raw ocean water or lake water or raw oil storage liquid or raw waste water or other liquid.
  • the liquid filling the vessel or tubes or both in the present step may be considered the higher density liquid.
  • the implementation may involve attaching one or more weights or anchors to near the bottom of the vessel and one or more buoyant floats to near the top of the vessel.
  • the float or near top of the vessel or combination thereof may be further attached to a line, which may be connected by a connector comprising a detachable mechanism, such as clip, or remotely detachable clip.
  • the guide line When the vessel reaches its desired depth (for example: the depth at which the weight or anchor reaches the bottom) the guide line may be detached or may be attached to a float specifying the location.
  • step 8 To discharge, open valve, allowing pressurized low-density liquid (for example: from step 8) to the generator (which may be, for example, a separate generator or may be a pump that can reversibly be used as a generator).
  • the generator which may be, for example, a separate generator or may be a pump that can reversibly be used as a generator.
  • Embodiment may comprise three tanks (two on surface, one on ocean floor), two pipes and one pump / generator
  • HDL high density liquid
  • reagents that are substantially insoluble or immiscible. It may be desirable for the high density liquid and low density liquid to be substantially insoluble or immiscible in each other.
  • low cost reagents include, but are not limited to, low cost reagents, low density for low density liquid, and / or low corrosion or non- corrosive reagents.
  • low cost reagents include, but are not limited to, low cost reagents, low density for low density liquid, and / or low corrosion or non- corrosive reagents.
  • propane are low cost and liquid at higher pressure operation.
  • polypropylene or HDPE is inexpensive, abundant, corrosion resistant, and compatible with water, seawater, butane and propane.
  • the energy storage device may also be a means of storing hydrocarbon liquids or chemicals or volatile hydrocarbons.
  • the LDL storage region and lower head height storage region may comprise storage for hydrocarbons, such as, for example, including, but not limited to, crude oil, gasoline, diesel, kerosene, ethane, propane, butane, hexane, octane, cyclopropane, or decane, or a combination thereof.
  • Hydrocarbon liquids are stored in small, medium, or large quantities before they are used or transported in various applications, such as polymer production, fuel, or other uses. By employing the energy storage device as a simultaneous relatively low density liquid storage device, the capital expense of the hydrocarbon liquids may be avoided.
  • oil & gas companies, hydrocarbon transport companies, oil traders, commodity traders, chemical companies, and other users of hydrocarbons or other relatively low density liquids may employ the present energy storage device as a hydrocarbon liquid storage device.
  • the owners or operators of the energy storage device may be compensated for the storage or service or storing the relatively low density liquids.
  • the relatively low density liquids may be purchased, in the present embodiment, the relatively low density liquids may advantageously not be purchased by the owner or operator of the energy storage device.
  • the owner or operator of the energy storage device may be compensated for properly storing the relatively low density liquids. This may eliminate the need to pay the capital expense of purchasing the hydrocarbon liquids, while also developing a new revenue source for storing the hydrocarbon liquids.
  • High density liquid may comprise a higher density liquid with limited solubility in water, such as propylene carbonate (density of ⁇ 1.2g/cm3) or ethylene glycol diacetate (density of ⁇ 1.128g/cm3).
  • propylene carbonate density of ⁇ 1.2g/cm3
  • ethylene glycol diacetate density of ⁇ 1.128g/cm3
  • Said higher density liquids may be low cost, non-volatile, and relatively non-toxic, enabling their use in large volumes in aquatic or marine environments. Aquatic and marine are used interchangeably herein.
  • Ridged storage regions or containers may be employed for the storage region or regions located beneath the surface of the water.
  • Said storage regions may include, but are not limited to, storage containers presently employed to store crude oil or chemicals beneath the surface of the ocean or other water body.
  • Storage regions, including non-ridged or ridged storage regions or containers may be located outside the water or liquid body. Alternatively or additionally, the storage regions may be located in strategic oil reserves, oil storage, natural gas storage, liquids storage, saline aquifers, geological formations, or oil & gas wells. It may be desirable for one or more storage regions experiencing greater than atmospheric pressure hydrostatic pressure to be in an environment where the surroundings exert a similar or supplemental pressure to minimize the strength requirements and potential cost of a storage region or container.
  • the geological formation or artificially constructed geological formation may function to contain or store said liquids directly and may function as a storage region on its own.
  • An energy storage device comprising: o Two or more storage regions o Wherein at least one storage region is at a greater pressure than another storage region o Wherein energy is stored using the difference in pressure between a lower density liquid and a higher density liquid at the same head height or depth
  • An energy storage device comprising: o Two or more storage regions o Wherein at least one storage region is at a greater pressure than another storage region o Wherein said energy storage device is charged by pumping a relatively low density liquid into a storage region to displace a relatively higher density liquid o Wherein said energy storage device is discharged by allowing a relatively higher density liquid to displace a relatively lower density liquid and allowing the flow of said lower density liquid to power a generator or hydraulic turbine
  • a subsea oil or chemicals storage facility which simultaneously functions as a large-scale energy storage device comprising: o Two or more storage regions o Wherein at least one storage region is at a greater pressure than another storage region o Wherein energy is stored using the difference in pressure between a lower density liquid and a higher density liquid at the same head height or depth
  • a subsea oil or chemicals storage facility which simultaneously functions as a large-scale energy storage device comprising: o Two or more storage regions o Wherein at least one storage region is at a greater pressure than another storage region o Wherein said energy storage device is charged by pumping a relatively low density liquid into a storage region to displace a relatively higher density liquid o Wherein said energy storage device is discharged by allowing a relatively higher density liquid to displace a relatively lower density liquid and allowing the flow of said lower density liquid to power a generator or hydraulic turbine •
  • a process for storing energy/electricity while simultaneously storing natural gas comprising o Storing natural gas in gas bags or a storage region beneath the surface of a water body o Storing electricity compressing or pumping natural gas into said gas bag or storage region, which may expand the volume of said storage region o Discharging or generating electricity by allowing said natural gas leave said gas bag or storage region and pass through a generator or turbine o Wherein said storage region is connected to a natural gas pipeline or LNG facility or natural gas facility
  • the pump may function as a generator reversibly
  • one storage region is located beneath the surface of a water body and another storage region is located near or above the surface of a water body
  • said said low density liquid or high density liquid or both are the oil or chemicals requiring storage
  • said storage region beneath the surface of a water body contains a concave region with an opening near the bottom of said concave region open to the surrounding water body
  • a drum or separator separates or is located between the lower density liquid and the water from the surrounding water body
  • said storage region beneath the surface of a water body comprises an expandable or contractible or flexible structure, such as a bladder or bag or balloon, which may expand and fill with low density liquid during charging and collapse or contracted or empty during discharging •
  • said storage region comprising an expandable or contractible or flexible structure may displace water around said storage region
  • the high density liquid constitutes water or water body surrounding a storage region
  • said storage region beneath the surface of the water body may be anchored or tethered to the ground near the bottom of said water body
  • the low-density liquid or the high density liquid or a both comprise the chemicals being stored
  • a processing unit is employed to separate out residual high density liquid from low density liquid or vise versa before said liquid or liquids are used or transported after removal from said storage region
  • the storage units may be employed for storage of oil or chemicals when excess storage is required
  • the storage units may contain more of, or filled with, or almost fully filled with, or filled with more of low-density liquid to temporarily or semi-permanently or permanently employed for oil or chemical storage, for example, in the event said storage is needed
  • the storage units may contain more of, or filled with, or almost fully filled with, or filled with more of high-density liquid to temporarily or semi-permanently or permanently employed for oil or chemical storage, for example, in the event said storage is needed •
  • the system may be optimized to prioritize or balance energy storage or oil storage or chemical storage or a combination thereof depending on, for example, including, but not limited to, one or more or a combination of the following: o The amount of chemicals or oil requiring storage o The market rate/price for chemical or oil storage o The market rate/price of energy storage in the electricity grid o The arbitrage value available for energy storage o The arbitrage value available for chemical storage
  • the low density liquid is a low density fluid
  • said low density fluid comprises a gas
  • said low density fluid or gas may comprise natural gas
  • said natural gas may be employed in said system for energy generation and oil natural gas storage
  • natural gas may be stored in the form of compressed natural gas (CNG) or liquid natural gas (LNG)
  • said storage region is connected to a natural gas pipeline or LNG facility or natural gas facility on the surface through one or more tubes or pipes
  • a process for storing energy/electricity while simultaneously storing natural gas comprising o Storing natural gas in gas bags or a storage region beneath the surface of a water body o Storing electricity compressing or pumping natural gas into said gas bag or storage region, which may expand the volume of said storage region o Discharging or generating electricity by allowing said natural gas leave said gas bag or storage region and pass through a generator or turbine o
  • said storage region is connected to a natural gas pipeline or LNG facility or natural gas facility on the surface through one or more tubes or pipes
  • Lower head height, higher pressure storage region may be equivalent to the storage region beneath the surface of a water body Energy Density (Butane - Water):
  • Low density liquid or high density liquid may be sourced from, for example, waste products.
  • the low density liquid or the high density liquid may be sourced from, for example, including, but not limited to, one or more or a combination of the following: waste cooking oil, waste plastic, waste plastic converted into liquids, waste plastic converted into fuel oil, waste glycerol, waste alcohol, waste coolant, waste antifreeze, waste lubricant, waste fuel, contaminated oil, contaminated chemicals, or expired goods.
  • the present invention pertains to a system for storing energy.
  • the present invention stores energy in the hydrostatic pressure difference between a lesser density liquid and a greater density liquid over the same hydraulic head or depth.
  • the present invention may involve storing energy by displacing water or other greater density liquid with a lesser density liquid.
  • Said displacing of water with a lesser density liquid may involve pumping lesser density liquid to a greater depth beneath the surface of water or other body of liquid.
  • Said pumping may consume power, such as electricity, and convert said power into gravitational potential energy and / or energy stored in a hydrostatic pressure difference.
  • Said stored energy may be converted back into power by allowing said lesser density liquid to be released from said greater depth beneath the surface of water or other body of liquid to a lesser depth beneath the surface of water or other body of liquid, passing through a generator in the process.
  • Figure 30 may show an energy storage system where the first storage reservoir is located on land and the pump and / or generator is located on land.
  • the second storage reservoir is located beneath the surface of a water body at a greater hydrostatic pressure and / or greater depth beneath the surface of a water body than the first storage reservoir.
  • the first storage reservoir, the pump and / or generator, and the second storage reservoir may be connected using pipes.
  • Figure 30 may show the energy storage system undergoing charging. Charging may involve storing power by pumping low density liquid from the first storage reservoir to the second storage reservoir.
  • Storage reservoirs may comprise expandable and / or contractable or collapsible tanks.
  • the first storage reservoir may contract or collapse into a smaller volume as liquid is pumped from the first storage reservoir to the second storage reservoir.
  • the second storage reservoir may expand into a larger volume as liquid is pumped from the first storage reservoir to the second storage reservoir.
  • Figure 31 may show an energy storage system where the first storage reservoir is located on land and the pump and / or generator is located on land.
  • the second storage reservoir is located beneath the surface of a water body at a greater hydrostatic pressure and / or greater depth beneath the surface of a water body than the first storage reservoir.
  • the first storage reservoir, the pump and / or generator, and the second storage reservoir may be connected using pipes.
  • Figure 31 may show the energy storage system undergoing discharging. Discharging may involve releasing stored energy by allowing the release of lower density liquid from the first storage reservoir to the second storage reservoir, generating power in the process by allowing said low density liquid to pass through a generator.
  • Storage reservoirs may comprise expandable and / or contractable or collapsible tanks.
  • the first storage reservoir may expand into a larger volume as liquid is released from the second storage reservoir to the first storage reservoir.
  • the second storage reservoir may contract or collapse into a smaller volume as liquid is released from the second storage reservoir to the first storage reservoir.
  • Figure 32 may show an energy storage system where the first storage reservoir is located near, at, or beneath the surface of a water body and/or the pump and / or generator is located near, at or beneath the surface of a water body.
  • the second storage reservoir is located beneath the surface of a water body at a greater hydrostatic pressure and / or greater depth beneath the surface of a water body than the first storage reservoir.
  • the first storage reservoir, the pump and / or generator, and the second storage reservoir may be connected using pipes.
  • Figure 32 may show the energy storage system undergoing charging.
  • Figure 33 may show an energy storage system where the first storage reservoir is located near, at, or beneath the surface of a water body and/or the pump and / or generator is located near, at or beneath the surface of a water body.
  • the second storage reservoir is located beneath the surface of a water body at a greater hydrostatic pressure and / or greater depth beneath the surface of a water body than the first storage reservoir.
  • the first storage reservoir, the pump and / or generator, and the second storage reservoir may be connected using pipes.
  • Figure 33 may show the energy storage system undergoing discharging.
  • Electricity may be transferred from or to an electricity grid or application requiring or supply electricity.
  • Electricity may be transferred using, for example, undersea or underground or above ground or a combination thereof power lines.
  • the lines / arrows between ‘ 1 ’ and ‘3’ and ‘3’ and ‘2’ may represent the transfer of low density liquid between these process elements.
  • Liquid may be transferred using, for example, pipes or transport vehicles. If liquid is transferred using pipes, it may be desirable for said pipe to be, including, but not limited to, one or more or a combination of the following: located on the surface of the ground, or suspended above the surface of the ground, or located beneath the ground, or comprise a subsurface pipeline, or comprise an underground pipeline, or comprise a pipeline beneath water and above ground, or comprise a pipeline beneath ground and beneath water, or comprise a pipeline above water and above ground.
  • Expandable or collapsible reservoir may comprise a liquid storage vessel which can expand or contract in volume to allow for the storage of more or less liquid, respectively.
  • the pressure inside said reservoir may be close to or equal to the pressure surround said reservoir.
  • Said reservoirs may include, but is not limited to, expandable or collapsible liquid storage devices, which may include, but are not limited to, one or more or a combination of the following: pillow tanks, or onion tanks, or balloon tanks, or bag tanks, fabric tanks, or bladder tanks, or folding tanks, or flexible tanks, or bellows tanks, or accordion tanks, or liner tanks.
  • the present invention may comprise a LPG storage facility, or an oil storage facility, or a strategic LPG reserve, or a strategic oil reserve.
  • the present invention may be employed to store a fuel or commodity chemical, while simultaneously employing said fuel or other commodity chemical as an gravitational electricity storage medium. This may enable the owner or operator of the facility to have an additional source of revenue (the storage or release of electricity), in addition to revenue from the storage of the fuel or other commodity chemical.
  • the facility owner may be paid storage fees to store the low density liquid, which may further improve economics of the facility.
  • a proportion of the low density liquid storage in the facility may be available for ‘commodity storage’ while a proportion of the low density liquid storage in the facility may be intended for permanent or semi-permanent storage.
  • the proportion of low density liquid storage available for ‘commodity storage’ relative to the proportion of low density liquid storage intended to be permanently or semi-permanently in the facility may vary by facility and may be dependent on multiple economic factors and the priorities of the facility.
  • Compmodity storage may comprise flexible or semi -flexible storage may comprise a portion of the storage facility’s low density liquid in storage which may be removed or added on a regular basis for market needs, such as commodity traders or other entities involved with the commodity market.
  • the proportional low density liquid storage capacity devoted to ‘commodity storage’ may comprise the proportion of low density liquid which can be added or removed without substantially impacting the performance or capacity or capabilities of the electricity storage.
  • the threshold of said ‘substantially impacting’ may vary by facility based on economic factors and facility priorities.
  • ‘Semi-permanent storage’ may comprise long term storage or storage which may be utilized in periodic or very rare instances.
  • applications for semi-permanent storage may include, but are not limited to, storage for a commodity asset backed fund, storage for a commodity asset backed ETF or ETN, or storage for a strategic reserve.
  • Permanent storage may involve low density liquid which is intended to remain in the facility and / or may be necessary for the proper operation of the facility.
  • Stored low density liquid may be employed as a stored asset or physical asset backing a commodity tracking ETF or other fund.
  • the low density liquid storage facility owner or operator may generate revenue from the electricity markets as an energy storage service, as well as generate revenue from the management fees generated by the ETF for storing the low density liquid backing the ETF.
  • the ability to have these two revenue streams may enable the facility owner or operator to generate more revenue from the facility, or may enable lower CAPEX of the facility, or may enable lower management fees for the ETF, or a combination thereof.
  • a portion of the low density liquid may be always stored in storage reservoir ‘1’ to satisfy short term needs of low density liquid.
  • the temperature of water in the ocean beneath a certain depth may be relatively stable. Liquid in storage reservoir ‘2’ be cooled or heated by the surrounding ocean water temperatures, depending on the ambient temperature conditions surrounding reservoir ‘1’ and the ambient conditions surrounding reservoir ‘2’. For example, the ambient conditions surround reservoir ‘2’ may be colder than the ambient conditions surrounding reservoir ‘1’. In said example, the relatively cool temperatures of liquid transferred from reservoir ‘2’ to reservoir ‘1’ may be harnessed to supply cooling to one or more applications requiring cooling. An example application requiring cooling may be the pump or generator ‘3 ⁇ For example, the ambient conditions surround reservoir ‘2’ may be warmer than the ambient conditions surrounding reservoir ‘1’.
  • the relatively warm temperatures of liquid transferred from reservoir ‘2’ to reservoir ‘1’ may be harnessed to supply heating or enthalpy to one or more applications requiring heating or enthalpy.
  • Said certain depth may comprise less than, greater than or equal to, one or more or a combination of the following: 300 meters, or 400 meters, or 500 meters, or 600 meters, or 700 meters, or 800 meters, or 900 meters, or 1,000 meters, or 1,100 meters, or 1,200 meters, or 1,300 meters, or 1,400 meters, or 1,500 meters, or 1,750 meters, or 2,000 meters.
  • the round trip efficiency of the present pressure and/or gravitational energy storage device may possess a significantly greater round trip efficiency relative to energy storage devices which employ pressurized gases.
  • the round trip efficiency of the present invention may be greater than or equal to 40%, or 50%, or 60%, or 70%, or 75%, or 80%, or 85%, or 90% or 95%.
  • the low density liquid may possess a low viscosity, for example, a viscosity near, equal to, or less than water.
  • a low viscosity for example, a viscosity near, equal to, or less than water.
  • butane possesses a dynamic viscosity of -0.2 cP at 1°C, compared to a dynamic viscosity of 1.73 cP at 1°C for water.
  • Other low density liquids other than or in addition to butane may possess a lesser viscosity than water.
  • Low viscosity may be advantageous, for example, because lower viscosity liquids may enable smaller pipe diameter, lower CAPEX, lower pumping energy losses, greater round-trip efficiency, and greater distances between reservoir ‘1’ and reservoir ‘2’.
  • Reservoir ‘2’ and / or reservoir ‘1’ may be anchored or connected or fixed or tethered to the land on the bottom of the body of liquid (e.g. body of water).
  • body of liquid e.g. body of water
  • Storage reservoirs or tanks may include, but are not limited to, one or more or a combination of the following: a pillow tank, or an onion tank, or a balloon tank, or a bag tank, or a fabric tank, or a bladder tank, or a folding tank, or a flexible tank, or a bellows tank, or an accordion tank, or a liner tank, or a rigid tank, or a piston tank, or an actuator tank, or a valve tank, or a basin tank, or a cement tank, or a wood tank, or a plastic tank, or a ceramic tank, or a fiber tank, or a composite tank, or a rubber tank, or a flexible tank.
  • a pillow tank or an onion tank, or a balloon tank, or a bag tank, or a fabric tank, or a bladder tank, or a folding tank, or a flexible tank, or a bellows tank, or an accordion tank, or a liner tank, or a rigid tank, or a piston tank, or an actuator
  • Pipe materials may include, but are not limited to, one or more or a combination of the following: plastic pipes, composite pipes, metallic pipes, fiber pipes, resin pipes, wood pipes, cement pipes, flexible pipes, rubber pipes, rigid pipes.
  • first and / or second reservoirs may be desirable to attach to higher density materials to reduce the buoyance of the reservoirs.
  • the distance between the reservoir and land at the bottom of a water body be substantial enough to justify the attachment of higher density materials to the first reservoir to reduce the cost of tethering cables.
  • Tethering cables may be employed to counteract the buoyancy of a reservoir and / or to ensure the reservoir is in an appropriate location relative to the other reservoir(s).
  • the distance between the first reservoir and land at the bottom of a water body may be sufficiently substantial the attachment of higher density materials to the first reservoir costs less than the cost reduction in the of tethering cables.
  • the location of the first reservoir may be maintained using a dynamic positioning system.
  • a dynamic positioning system may employ various sensors, or GPS, or radar, or other positioning instruments to inform an operating system of changes in the current position and / or changes in position of the first reservoir and / or external thrust vectors, such as currents. If the position changes of the first reservoir changes and / or if a thrust vector is detected, aquatic or marine engines may be employed to counteract said external thrust vectors and / or changes in position to ensure the first reservoir maintains a desirable position. If desirable, the higher density material attachments to the first reservoir may make the first reservoir at a similar density or neutral density relative to the surrounding water body.
  • the first reservoir may employ mechanisms to dynamically adjust its density, using, for example, the addition of higher density material, the addition of lower density material (for example: low density liquid or a gas, such as air), the release of higher density material, or the release of lower density material).
  • Said mechanism(s) to dynamically adjust density may also be incorporated within a dynamic positioning system.
  • a dynamic positioning system may also be employed in the second reservoir.
  • Collapsible or contractable may involve a structure or vessel or tank which can decrease in occupied volume or storage capacity reversibly.
  • Expandable may involve a structure or vessel or tank which can increase in occupied volume or storage capacity reversibly.
  • Lower density liquid may be soluble or partially soluble in the higher density liquid.
  • the lower density liquid may be separate from the higher density liquid with a physical barrier, which may prevent the dissolution of lower density liquid in higher density liquid.
  • said physical barrier may involve a storage tank liner or walls or pipes or a combination thereof.
  • low density liquids or liquids with a density less than water may have a boiling point near or less than the outside air or water temperature and / or may possess a large vapor pressure at the temperature of the outside air or water.
  • the first reservoir may be a pressurized or rigid tank.
  • a pressurized or rigid storage tank may enable low density liquid to remain at a liquid phase while being at a temperature above the low density liquid’s atmospheric pressure boiling point.
  • a rigid or pressurized tank is employed at the first storage reservoir, when liquid, such as low density liquid, is removed from the first storage reservoir, the total volume of the rigid or pressurized tank may remain the same.
  • a volume in the tank formerly occupied by liquid phase low density liquid may instead be occupied by gas phase low density liquid.
  • Said gas phase low density liquid may exist in the head space above liquid phase inside the tank, such as liquid phase low density liquid.
  • liquid, such as low density liquid is added to the first storage reservoir, the total volume of the rigid or pressurized tank may remain the same.
  • a volume in the tank formerly occupied by gas phase low density liquid may instead be occupied by liquid phase low density liquid.
  • Example low density liquids which may be applicable may include, but not limited to, Liquefied Petroleum Gas (LPG), or propane, or butane, or diethyl ether, or dimethyl ether, or methoxypropane, or methanol, or acetone, or pentane, or hexane, or petroleum ether, or methoxy ethane, or liquid natural gas (LNG), or gasoline, or Diisopropyl ether, or alkanes, or alkenes, or alkynes, or cycloalkanes, or a combination thereof.
  • LPG Liquefied Petroleum Gas
  • propane propane
  • butane or diethyl ether
  • dimethyl ether or methoxypropane
  • methanol or acetone
  • pentane or hexane
  • petroleum ether or methoxy ethane
  • LNG liquid natural gas
  • Diisopropyl ether or alkanes, or alkenes, or alkynes,
  • a containment mechanism such as, for example, including but not limited to, a liner, or blanket, or tarp, or fabric, or funnel, or float, or other containment mechanism, or a combination thereof, may be placed above or suspended above the second reservoir and / or pipes and / or pipe connections.
  • a containment mechanism may be placed above or suspended above the second reservoir and / or pipes and / or pipe connections.
  • low density liquid may rise from the leak and may be captured or caught by said containment mechanism.
  • Said containment mechanism may be effective because low density liquid may tend to float and said containment mechanism may cover a portion or the entire surface area of the second reservoir and / or pipes and / or pipe connections above said second reservoir and / or pipes and / or pipe connections.
  • Low density liquid captured by said containment mechanism may be, if desirable, funneled within said containment mechanism and, if desirable, may be transferred to the surface using a return pipe, where the low density liquid may be recovered.
  • the contact of low density liquid with a portion of the containment vessel or pipe may trigger a sensor or sensors which alert system operators of the need to fix a leak.
  • the said sensor may involve a mechanism for measuring the increased buoyancy of the containment mechanism due to the capturing or containment of leaked low density liquid.
  • said sensor may involve a mechanism for measuring the flow rate of liquid in said return pipe, wherein the presence of at least a certain liquid flow rate may indicate the presence of a low density liquid leak.
  • said sensor may involve a mechanism for detecting low density liquid using spectroscopy or measurements of density or molecular weight or a combination thereof.
  • said sensor may involve measuring the change in mass or pressure or volume in a container connected to said return pipe.
  • said sensor may involve measuring changes in mass or capacity in the first or second reservoir, which may include changes in said mass or energy storage capacity when the process is at a steady state or unexplained changes in mass or energy storage capacity.
  • a first reservoir may employ said containment mechanisms and / or sensors.
  • a first reservoir and / or pump and / or generator may employ said containment mechanisms and / or sensors if, for example, a first reservoir and / or pump and / or generator is located beneath the surface of a water body.
  • Low density liquid or pipes or vessels or reservoirs or a combination thereof may contain a medium which reacts in the event of or at the site of a leak.
  • a material in the walls of a pipe or vessel or reservoir may react with low density liquid if low density liquid begins to leak.
  • Said reaction may inhibit or block or prevent a leak.
  • Said reaction may involve, including, but not limited to one or more or a combination of the following: an absorption reaction, or a swelling reaction, or a foaming reaction, or an expansion reaction, a reaction to form a solid, a reaction to form a viscous liquid, or a combination thereof.
  • the low density liquid or walls of pipes or vessels or reservoirs or a combination thereof may contain a reagent which reacts with water or air or salt in water upon exposure to water or air.
  • Said reaction may inhibit or block or prevent a leak.
  • Said reaction may involve, including, but not limited to one or more or a combination of the following: an absorption reaction, or a swelling reaction, or a foaming reaction, or an expansion reaction, a reaction to form a solid, a reaction to form a viscous liquid, or a combination thereof.
  • Said reaction may involve forming a material which is more easily or readily captured, or a material which is more environmentally friendly, or a material which may inhibit further leakage, or a material which may simplify or facilitate the process of leakage detection, or a material which may reduce the cost or damage associated with a leakage.
  • said reaction may involve forming a liquid of a certain color or said reaction may involve a tracing reagent.
  • a tracing reagent Low density liquid or pipes or vessels or reservoir or a combination thereof may contain a tracing chemical or reagent which may facilitate leak detection.
  • parts or components of pipes or vessels or reservoir may contain a material, which, when exposed to water, or salt water, or low density liquid, or air, or a combination thereof, may change one or more properties to facilitate detection of leaks or wear or other forms of damage or exposure.
  • said properties may include, but are not limited to, color, electrical conductivity, electrical resistivity, thermal conductivity, surface texture, surface morphology, absorbance spectra, vibration frequency, flexibility, temperature, density, rigidity, or a combination thereof.
  • the temperature beneath a water body and the temperature above a water body may be different. Additionally, water bodies themselves may possess a range of different temperatures, which may correlate with depth. The temperature of a water body relative to its depth may be known as a water body thermocline.
  • the temperature of a water body below about 1000 meters or about 1250 meters or about 1500 meters ranges from about 3 to 8°C because water is generally most dense at about 4°C.
  • the temperature of the water below 1500 meters is generally near 4°C, even if the temperature of the water at the ocean surface is warm, such as, for example, greater than 15°C or greater than 20°C.
  • the second reservoir may be located at a different depth than the first reservoir.
  • the temperature of the water surrounding the second reservoir may be relatively constant or stable, if, for example, the second reservoir is located at a depth beneath a water body of greater than 100 meters, or 200 meters, or 300 meters, or 500 meters, or 700 meters, or 900 meters, or 1000 meters, or 1250 meters, or 1500 meters.
  • the temperature of the air or water adjacent to or surrounding the first reservoir may be different from the temperature off the water surrounding the second reservoir.
  • the temperature difference between the second reservoir and the first reservoir may be beneficially utilized or harnessed.
  • the temperature of the second reservoir is less than the first reservoir or the temperature of things adjacent to the first reservoir, power may be generated from the difference in temperature between liquid returning from the second reservoir and the surrounding ambient temperature near the first reservoir or the temperature inside the first reservoir or another heat source or thermal source or enthalpy source.
  • the temperature of the second reservoir is greater than the first reservoir or the temperature of things adjacent to the first reservoir, power may be generated from the difference in temperature between liquid returning from the second reservoir and the surrounding ambient temperature near the first reservoir or the temperature inside the first reservoir or another cold source or heat sink or enthalpy sink.
  • liquid from the second reservoir may be employed as a cooling medium or cooling source or for district cooling to provide valuable or useful cooling to one or more applications requiring cooling.
  • liquid from the second reservoir may be employed as a heating medium or heat source or for district heating to provide valuable or useful heating to one or more applications requiring heating.
  • liquid from the second reservoir may be employed as a cooling source to power or facilitate a desalination process or a process for removing water from gas streams or air.
  • the temperature of the second reservoir is less than the first reservoir or the temperature of things adjacent to the first reservoir, it may be desirable to insulate said first reservoir or one or more pipes. Said insulation may enable the first reservoir to remain at a cooler temperature, which may be advantageous, for example, if the low density liquid has a low boiling point or is volatile and minimizing temperature in the first reservoir minimizes pressure in the first reservoir. Said insulation may also prevent the formation of condensation on a tank.
  • the present invention may also be employed as a means for ocean thermal energy conversion (OTEC).
  • OEC ocean thermal energy conversion
  • one or more components of the present invention may be heated or cooled or temperature controlled or a combination thereof.
  • Low density liquid may possess a freezing point less than water, which may be advantageously utilized.
  • the first reservoir may be employed as a cold or thermal storage unit, for, for example, providing cooling for a refrigerated or frozen storage facility.
  • Said cold storage may be employed, for example, to optimize energy consumption or for grid load shifting or load curtailment.
  • the first reservoir may be employed as a cryogenic cold storage or thermal storage unit.
  • cool low density liquid may be employed as a low temperature heat transfer fluid and / or as a low temperature thermal storage medium.
  • low density liquid may be employed in applications which require cooling, which may include, but are not limited to, one or more or a combination of the following: district cooling, or cooling for a desalination facility, or cooling for a power plant, or cooling for an air separation unit, or cooling for a liquification facility, or cooling for a HVAC system.
  • LNG gasification facilities may produce significant waste cooling.
  • LNG gasification facilities may employ low density liquid in or from said first reservoir as a heat source or enthalpy source, cooling said low density liquid in the process. Due to its potentially lower freezing point, low density liquid may be cooled to a lower temperature than water while remaining at a liquid phase, enabling heat transfer or large scale thermal storage or both at temperatures near, at, or below the freezing point of water.
  • ‘warm’ low density liquid may be near 4°C or otherwise below ambient temperature.
  • ‘warm’ low density liquid may be significantly less than ambient temperatures, more energy may be recovered from ‘cold sources’ than if said low density liquid was near or at ambient temperatures o
  • Low density liquid or high density liquid or both may be employed as a heat transfer fluid, or as a thermal storage fluid, or may be employed in ocean thermal energy conversion.
  • a system for storing or generating electricity comprising: a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water; a second storage reservoir configured to be located below the surface of the body of water; a pump; and a generator; wherein the pump, generator, and the first and second reservoir are operatively connected such that electricity is stored by displacing water adjacent the second storage reservoir by pumping low density fluid in the first storage reservoir to the second storage reservoir and electricity is generated or discharged by allowing the low density fluid in the second storage reservoir to return to the first storage reservoir; and, wherein the water and the fluid which has a lower density than water are both in liquid form.
  • said second storage reservoir is a pillow tank, an onion tank, a balloon tank, a bag tank, a fabric tank, a bladder tank, a folding tank, a flexible tank, a bellows tank, an accordion tank, or a liner tank.
  • said second storage reservoir comprises a concave region with an opening near the bottom of said concave region wherein said opening is open to the body of water.
  • a system for storing or generating electricity comprising: a first storage reservoir configured to store a fluid which has a lower density than water; a second storage reservoir configured to be located below a surface of a body of water wherein the second storage reservoir is at a greater depth beneath the surface of a water body than the first storage reservoir; a pump; and a generator; wherein the pump, generator, and the first and second reservoir are operatively connected such that
  • Embodiment 7 The system of Embodiment 5 wherein the displaced water is water within the body of water and wherein the displaced water is adjacent the second storage reservoir.
  • said first storage reservoir, said second storage reservoir, or both comprise a pillow tank, an onion tank, a balloon tank, a bag tank, a fabric tank, a bladder tank, a folding tank, a flexible tank, a bellows tank, an accordion tank, or a liner tank.
  • Embodiment 13 The system of Embodiment 5 wherein the fluid having a lower density than water comprises a hydrocarbon liquid.
  • Embodiment 5 which further comprises a dynamic positioning system to maintain or adjust a position of the first reservoir, the second reservoir or both.
  • Embodiment 5 further comprising an operative connection to an electricity grid or electricity transmission infrastructure.
  • Embodiment 5 wherein the fluid having a lower density than water comprises propane, butane, LPG, pentane, hexane, or a mixture thereof.
  • Embodiment 21 The system of Embodiment 5 wherein the fluid having a lower density than water comprises an alcohol, an ether, an ester, or a mixture thereof.
  • Embodiment 5 wherein the fluid having a lower density than water comprises methanol, ethanol, propanol, acetone, dimethyl ether, diethyl ether, or a mixture thereof.
  • Embodiment 26 wherein said collapsing or contracting is due to water adjacent said second reservoir displacing the fluid having a lower density than water.
  • the present invention pertains to systems and methods for storing or generating electricity. Some embodiments pertain to systems or methods for the storage of energy by displacing a higher density liquid with a lower density liquid. Some embodiments relate to systems or methods for facilitating the storage or generation of electricity. Some embodiments relate to environmental, health, and safety mechanisms. Some embodiments related to systems and configurations to enable energy storage in particular geography types. Some embodiments related to systems and configurations to enable energy storage with low density liquid working fluids with various levels of volatility or vapor pressure. Some embodiments pertain to ensuring optimal energy storage performance.
  • Condensable Gas A chemical or mixture of chemicals which phase transitions from a liquid to a gas or a gas to a liquid or both reversibly or possesses a boiling point or a combination thereof at the following conditions: o Vapor pressures less than 2.5 atm, or less than 5 atm, or less than 10 atm, or less than 15 atm, or less than 20 atm o Vapor pressures greater than 0.1 atm, or greater than 0.2 atm, or greater than 0.3 atm, or greater than 0.4 atm, or greater than 0.5 atm, or greater than 0.6 atm, or greater than 0.7 atm, or greater than 0.8 atm, or greater than 0.9 atm, or greater than 1.0 atm o Temperature in the range of 230 Kelvin to 380 Kelvin • Partially Discharged or Partially Charged: A state where the energy storage system contains stored energy, although the stored energy is less than the energy storage system’s full capacity to store energy. For example, when a surface LDL storage tank contains an
  • Maximum capacity may comprise the maximum amount of HDL or water and / or the maximum amount of LDL or both which can be stored in a given storage tank or in a region of the energy storage device or in general.
  • the maximum capacity of LDL in a subsea tank may comprise the maximum amount of LDL which can be stored in a subsea tank before the LDL is at risk of or may enter or enters a pipeline designed for transferring water.
  • the maximum capacity of HDL in a subsea tank may comprise the maximum amount of water or HDL which can be stored in a subsea tank before the HDL is at risk of or may enter or enters a pipeline designed for transferring LDL.
  • the maximum capacity of LDL in a subsea tank may comprise the maximum amount of LDL which can be stored in a subsea tank before the LDL is at risk of or may enter or enters a surface HDL or water tank.
  • the maximum capacity of HDL in a subsea tank may comprise the maximum amount of water or HDL which can be stored in a subsea tank before the HDL is at risk of or may enter or enters a surface LDL tank.
  • Minimum capacity may comprise the minimum amount of HDL or water and / or the maximum amount of LDL or both which can be stored in a given storage tank or in a region of the energy storage device or in general.
  • the minimum capacity of a tank for LDL or HDL may comprise the tank containing no or very little LDL or HDL.
  • the minimum capacity of LDL in a subsea tank may comprise the minimum amount of LDL which can be stored in a subsea tank before the HDL is at risk of or may enter or enters a pipeline designed for transferring LDL.
  • the minimum capacity of HDL in a subsea tank may comprise the minimum amount of water or HDL which can be stored in a subsea tank before the LDL is at risk of or may enter or enters a pipeline designed for transferring HDL.
  • the minimum capacity of LDL in a subsea tank may comprise the minimum amount of LDL which can be stored in a subsea tank before the HDL is at risk of or may enter or enters a surface LDL tank.
  • the minimum capacity of HDL in a subsea tank may comprise the minimum amount of water or HDL which can be stored in a subsea tank before the LDL is at risk of or may enter or enters a surface HDL or water tank.
  • the minimum volume or amount of LDL in the floating underwater tank may comprise the minimum amount of LDL required to ensure the floating underwater tank is buoyant.
  • a pump and a generator may comprise a combined pump/generator unit, which may include, but is not limited to, a hydraulic power recovery turbine (HPRT). Alternatively, or additionally, some embodiments may employ a separate pump and a separate generator.
  • HPRT hydraulic power recovery turbine
  • the first reservoir comprises one or more or a combination of tanks configured to store low density liquid and may be located at an elevation higher or greater than a second reservoir.
  • the second reservoir comprises one or more or a combination of tanks configured to store low density liquid and may be located at an elevation lower or less than the first reservoir.
  • the second reservoir may be configured to store both low density liquid and water.
  • the second reservoir may be configured to store both low density liquid and water in a manner which low density liquid and water exchange volume or pressure, while preventing mixing or direct physical contact between the water and the low density liquid.
  • the third reservoir may be interconnected to or comprise the ocean.
  • the third reservoir may comprise a water tank or storage vessel.
  • Said water tank or storage device may be on the surface, or above water, or underwater, or a combination thereof.
  • An underwater water reservoir may comprise a tank or storage vessel or reservoir or water body comprising water interconnected to the second reservoir via a pipe. If desirable, at least a portion of the water tank or storage vessel third reservoir or water interconnected to the third reservoir may possess similar pressures or equilibrium pressure with the hydrostatic pressure of the ocean. If the density of the liquid inside the third reservoir is the same as ocean water, the third reservoir may be located at any elevation between the elevation of the first storage reservoir and the second storage reservoir or any elevation underwater.
  • a storage vessel or tank may comprise a barrier to contain a material, such as a liquid, solid, or gas.
  • a storage vessel or tank may comprise various configurations or materials, and may include, but is not limited to, storage tanks or vessels employed for storing liquid or multiphase media or a combination thereof known in the art.
  • Treated Ocean Water Treated ocean water may comprise water or aqueous solution origination from ocean water which is less corrosive than ocean water, or possesses a lower dissolved oxygen concentration than ocean water, or is less prone to the formation of biofouling or scaling than ocean water, or a combination thereof. It may be desirable for treated ocean water to possess a similar density to ocean water.
  • a tether may comprise a cable or line or connector which connects a floating or buoyant structure with another structure.
  • Said ‘another structure’ may comprise, including, but not limited to: the seafloor or a mooring or a vessel or another tank or an anchor, or a combination thereof.
  • the present term may describe a reservoir or storage which is designed for the storage of water and a lower density liquid.
  • the present term may include configuring storage which prevents water and lower density liquid from reacting, or dissolving, or forming a new phase.
  • the present term may include configuring storage which ensures water and lower density liquid are physically separate while stored the same storage vessel.
  • Low Density Liquid A liquid with a lower density than a higher density liquid. A liquid with a lower density than the density of water. A liquid with a lower density than liquid water at a temperature greater than 3°C and / or less than 50°C.
  • Substantial Low Density Liquid - Water Hydrates “Substantial” may mean an amount or location or combination thereof of Low Density Liquid - Water Hydrates such that Low Density Liquid - Water Hydrates interferes with or disrupts the operation of the energy storage system.
  • a sub-tank may comprise a tank within or located on the inside of another tank or enclosed structure or concave structure or a combination thereof.
  • a rigid containment structure may comprise an enclosure or cover which holds a sub-tank or one or more other structures.
  • a rigid containment structure may capture or recover low density liquid and / or debris in the event of a breach in a sub-tank or one or more other structures.
  • An underwater tank mechanically isolated from ocean water surrounding or adjacent to it may involve a tank in which contents inside the tank operate under pressures isolated or independent from the pressure of the contents surrounding the tank.
  • a mechanically isolated tank may be a tank which does not exchange pressure with fluids or materials outside or surrounding the tank.
  • an underwater tank may possess a pressure inside the tank which is different from the pressure of the water surrounding the underwater tank - the shape and / or volume of the tank may remain unchanged.
  • the pressure inside an underwater tank may be close to or about equivalent to the hydrostatic pressure of water at the same depth as the tank, however the internal contents of the tank may not be exchanging pressure with the ocean water adjacent to or surrounding the tank.
  • an engineered head space gas or condensable head space gas may be engineered to have a vapor pressure in the pressure range of the hydrostatic pressure of ocean water at the same depth as tank at a temperature in the range of the temperature inside the tank and / or the temperature of water surrounding or adjacent to said tank.
  • an underwater tank or underwater rigid tank for example, can be made from less material or less expensive materials or a combination thereof.
  • Breach A breach may comprise a break or leak or disconnection or accidental release which may result in the release of internal liquids, which may include, but is not limited to, low density liquid and / or water.
  • Figure 34 The present figure may show an energy storage system which stores electricity by pumping a low density liquid from a tank at a higher elevation to a tank at a lower elevation, displacing water in the tank at a lower elevation.
  • the present figure may show the present embodiment charging or storing electricity.
  • the tank with low density liquid at a higher elevation may comprise a first reservoir.
  • the tank with low density liquid and water at a lower elevation may comprise a second reservoir.
  • the tank with water at a higher elevation may comprise a third reservoir or surface water tank.
  • the density of water in the surface water tank may be close to or equal to the density of the ocean water.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 35 The present figure may comprise the same embodiment as Figure 34.
  • the present figure may show the present embodiment at a nearly fully charged state.
  • Figure 36 The present figure may comprise the same embodiment as Figure 34.
  • the present figure may show the present embodiment discharging or generating electricity.
  • Figure 37 The present figure may comprise the same embodiment as Figure 34.
  • the present figure may show the present embodiment at a nearly fully discharged state.
  • Figure 38 Figure key for figures 34, 35, 36, and 37.
  • Figure 39 An energy storage system which stores electricity by pumping low density liquid from a first reservoir (“1”) near the surface into an underwater second reservoir (“2”), displacing ocean water surrounding said second reservoir.
  • the present figure shows the energy storage system charging by pumping low density liquid from the first reservoir to a second reservoir, displacement water surrounding the second reservoir.
  • the first reservoir (“1”) near the surface may be at an elevation greater than the elevation of the second reservoir (“2”).
  • the first reservoir may be above water on land, or floating in the water, or underwater.
  • the second reservoir is floating above the ocean floor.
  • the second reservoir may be suspended above the ocean floor and may be buoyant.
  • the second reservoir may be tethered to the ocean floor and / or anchored to the ocean bottom.
  • the second reservoir may be surrounded by ocean water.
  • the second reservoir may comprise a piston tank.
  • the second reservoir may comprise an expandable or collapsible structure, such as an onion tank, or a bladder tank, or a pillow tank, or a storage bag.
  • the internal pressure of the second reservoir may be close to or about equivalent to the hydrostatic pressure of water in contact with the bottom of the second reservoir.
  • Figure 40 An energy storage system which stores electricity by pumping low density liquid from a first reservoir (“1”) near the surface into an underwater second reservoir (“2”), displacing ocean water surrounding said second reservoir.
  • the present figure shows the energy storage system fully charged at a steady state.
  • the first reservoir (“1”) near the surface may be at an elevation greater than the elevation of the second reservoir (“2”).
  • the first reservoir may be above water on land, or floating in the water, or underwater.
  • the second reservoir is floating above the ocean floor.
  • the second reservoir may be suspended above the ocean floor and may be buoyant.
  • the second reservoir may be tethered to the ocean floor and / or anchored to the ocean bottom.
  • the second reservoir may be surrounded by ocean water.
  • the second reservoir may comprise a piston tank.
  • the second reservoir may comprise an expandable or collapsible structure, such as an onion tank, or a bladder tank, or a pillow tank, or a storage bag.
  • the internal pressure of the second reservoir may be close to or about equivalent to the hydrostatic pressure of water in contact with the bottom of the second reservoir.
  • Figure 41 An energy storage system which stores electricity by pumping low density liquid from a first reservoir (“1”) near the surface into an underwater second reservoir (“2”), displacing ocean water surrounding said second reservoir.
  • the present figure shows the energy storage system discharging or generating electricity, wherein low density liquid inside the second reservoir is displaced by water surrounding the second reservoir (“2”) and transferred through a pipe, through a generator, generating electricity, and into the first reservoir (“1”).
  • the first reservoir (“1”) near the surface may be at an elevation greater than the elevation of the second reservoir (“2”).
  • the first reservoir may be above water on land, or floating in the water, or underwater.
  • the second reservoir is floating above the ocean floor.
  • the second reservoir may be suspended above the ocean floor and may be buoyant.
  • the second reservoir may be tethered to the ocean floor and / or anchored to the ocean bottom.
  • the second reservoir may be surrounded by ocean water.
  • the second reservoir may comprise a piston tank.
  • the second reservoir may comprise an expandable or collapsible structure, such as an onion tank, or a bladder tank, or a pillow tank, or a storage bag.
  • the internal pressure of the second reservoir may be close to or about equivalent to the hydrostatic pressure of water in contact with the bottom of the second reservoir.
  • Figure 42 An energy storage system which stores electricity by pumping low density liquid from a first reservoir (“1”) near the surface into an underwater second reservoir (“2”), displacing ocean water surrounding said second reservoir.
  • the present figure shows the energy storage system at a fully discharged state.
  • the first reservoir (“1”) near the surface may be at an elevation greater than the elevation of the second reservoir (“2”).
  • the first reservoir may be above water on land, or floating in the water, or underwater.
  • the second reservoir is floating above the ocean floor.
  • the second reservoir may be suspended above the ocean floor and may be buoyant.
  • the second reservoir may be tethered to the ocean floor and / or anchored to the ocean bottom.
  • the second reservoir may be surrounded by ocean water.
  • the second reservoir may comprise a piston tank.
  • the second reservoir may comprise an expandable or collapsible structure, such as an onion tank, or a bladder tank, or a pillow tank, or a storage bag.
  • the internal pressure of the second reservoir may be close to or about equivalent to the hydrostatic pressure of water in contact with the bottom of the second reservoir.
  • Figure 43 is an energy storage system with tethers or anchors or tie down tethers labeled. “C” is labeling the tethers or anchors or tie downs. Said tethers or anchors or tie downs may be employed to connect an underwater tank (e.g. ‘2’) to the seafloor, which may enable an underwater tank (e.g. ‘2’) to be floating above the seafloor.
  • Figure 44 shows a water or HDL storage tank with a condensable gas in the headspace.
  • the storage tank may be rigid in construction.
  • “A” is labeling the yellow layer (light colored in black/white).
  • “A” represents a practically insoluble condensed liquid comprising a condensable gas at a condensed (i.e. liquid) state.
  • the said insoluble condensed liquid may comprise the same composition as the at least a portion of the gas in the headspace, “B”, and / or said insoluble condensed liquid vapor pression may be at equilibrium or in equilibrium with the headspace gas.
  • “B” represents the gases occupying the headspace.
  • a condensable headspace gas may enable the water tank to be drained of water while maintaining a relatively stable pressure inside said tank or without substantially reducing the pressure inside the water tank.
  • a condensable headspace gas may enable the inside of an underwater rigid water tank to have an internal pressure close to the hydrostatic pressure of ocean water at the depth of the underwater rigid tank, while remaining mechanically isolated from the ocean water at the depth of the underwater rigid tank.
  • a condensable headspace gas may have a vapor pressure or boiling point engineered to match a design pressure range within a design temperature range.
  • Figure 45 shows a water or HDL storage tank with a condensable gas in the headspace.
  • the storage tank may be rigid in construction.
  • “A” is labeling the yellow layer (light colored in black/white).
  • “A” represents a practically insoluble condensed liquid comprising a condensable gas at a condensed (i.e. liquid) state.
  • the said insoluble condensed liquid may comprise the same composition as the at least a portion of the gas in the headspace, “B”, and / or said insoluble condensed liquid vapor pression may be at equilibrium or in equilibrium with the headspace gas.
  • “B” represents the gases occupying the headspace.
  • a condensable headspace gas may enable the water tank to be drained of water while maintaining a relatively stable pressure inside said tank or without substantially reducing the pressure inside the water tank.
  • a condensable headspace gas may enable the inside of an underwater rigid water tank to have an internal pressure close to the hydrostatic pressure of ocean water at the depth of the underwater rigid tank, while remaining mechanically isolated from the ocean water at the depth of the underwater rigid tank.
  • a condensable headspace gas may have a vapor pressure or boiling point engineered to match a design pressure range within a design temperature range.
  • Figure 46 An energy storage system which stores electricity by pumping low density liquid into a rigid underwater tank to displace water inside said rigid tank, wherein said water is displaced to an external underwater water reservoir.
  • the present figure shows the present embodiment at a state of charging, for example, wherein electricity is powering a pump (“4”) to transfer low density liquid from a reservoir near the surface (“1”) to an underwater reservoir (“2”), for example, whereby low density liquid displaces water inside said underwater reservoir.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 46 An energy storage system which stores electricity by pumping low density liquid into a rigid underwater tank to displace water inside said rigid tank, wherein said water is displaced to an external underwater water reservoir.
  • the present figure shows the present embodiment at a fully charged, steady state.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 48 An energy storage system which stores electricity by pumping low density liquid into a rigid underwater tank to displace water inside said rigid tank, wherein said water is displaced to an external underwater water reservoir.
  • the present figure shows the present embodiment at a state of generating electricity or discharging.
  • a valve (“5”) may open, allowing water inside an underwater reservoir (“2”) to displace low density liquid from said underwater reservoir through a pipe (“3”), through a generator (“4”), generating electricity or discharging stored electricity, and into the reservoir near the surface (“1”).
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 49 An energy storage system which stores electricity by pumping low density liquid into a rigid underwater tank to displace water inside said rigid tank, wherein said water is displaced to an external underwater water reservoir.
  • the present figure shows the present embodiment at a fully discharged, steady state.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 50 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir, wherein said water is displaced to an external underwater water reservoir (third reservoir).
  • the present figure shows the present embodiment at a fully discharged, steady state.
  • “2” may represent a rigid underwater tank, which may comprise the second reservoir.
  • S may represent a separator or barrier, which may be located between the low density liquid and the water or may physically separate or prevent or minimize direct contact between the low density liquid and the water. Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water. Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “8” may represent an external water reservoir or the third reservoir. In the present figure, the external water reservoir may be located underwater. In the present figure, the external water reservoir may be underwater at a similar depth to the second reservoir.
  • “9” may represent a water pipe interconnecting an external water reservoir to the second reservoir.
  • the external water reservoir, or the pipe interconnecting the external water reservoir to the second reservoir, or a combination thereof may possess an internal pressure close to the hydrostatic pressure of the ocean water at or near the depth of the second reservoir.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 51 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir, wherein said water is displaced to an external underwater water reservoir (third reservoir).
  • the present figure shows the present embodiment at a state of charging, for example, wherein electricity is powering a pump (“4”) to transfer low density liquid from a reservoir near the surface (“1”) to a underwater reservoir (“2”), for example, whereby low density liquid displaces water inside said underwater reservoir.
  • “2” may represent a rigid underwater tank, which may comprise the second reservoir.
  • S may represent a separator or barrier, which may be located between the low density liquid and the water or may physically separate or prevent or minimize direct contact between the low density liquid and the water.
  • Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water. Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “8” may represent an external water reservoir or the third reservoir. In the present figure, the external water reservoir may be located underwater. In the present figure, the external water reservoir may be underwater at a similar depth to the second reservoir.
  • “9” may represent a water pipe interconnecting an external water reservoir to the second reservoir.
  • the external water reservoir, or the pipe interconnecting the external water reservoir to the second reservoir, or a combination thereof may possess an internal pressure close to the hydrostatic pressure of the ocean water at or near the depth of the second reservoir.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 52 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir, wherein said water is displaced to an external underwater water reservoir (third reservoir).
  • the present figure shows the present embodiment at a fully charged, steady state.
  • “2” may represent a rigid underwater tank, which may comprise the second reservoir.
  • “S” may represent a separator or barrier, which may be located between the low density liquid and the water or may physically separate or prevent or minimize direct contact between the low density liquid and the water. Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water.
  • Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “8” may represent an external water reservoir or the third reservoir. Said physical separation or barrier may comprise a membrane.
  • the external water reservoir may be located underwater. In the present figure, the external water reservoir may be underwater at a similar depth to the second reservoir.
  • “9” may represent a water pipe interconnecting an external water reservoir to the second reservoir.
  • the external water reservoir, or the pipe interconnecting the external water reservoir to the second reservoir, or a combination thereof may possess an internal pressure close to the hydrostatic pressure of the ocean water at or near the depth of the second reservoir. The pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • FIG. 53 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir, wherein said water is displaced to an external underwater water reservoir (third reservoir).
  • the present figure shows the present embodiment at a state of generating electricity or discharging.
  • a valve (“5”) may open, allowing water inside an underwater reservoir (“2”) to displace low density liquid from said underwater reservoir through a pipe (“3”), through a generator (“4”), generating electricity or discharging stored electricity, and into the reservoir near the surface (“1”) ⁇ “2” may represent a rigid underwater tank, which may comprise the second reservoir.
  • S may represent a separator or barrier, which may be located between the low density liquid and the water or may physically separate or prevent or minimize direct contact between the low density liquid and the water. Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water. Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “8” may represent an external water reservoir or the third reservoir. In the present figure, the external water reservoir may be located underwater. In the present figure, the external water reservoir may be underwater at a similar depth to the second reservoir.
  • “9” may represent a water pipe interconnecting an external water reservoir to the second reservoir.
  • the external water reservoir, or the pipe interconnecting the external water reservoir to the second reservoir, or a combination thereof may possess an internal pressure close to the hydrostatic pressure of the ocean water at or near the depth of the second reservoir.
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 54 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir into a separate water reservoir (third reservoir).
  • the third reservoir may comprise a tank at a higher elevation than the second reservoir and / or a tank which is at a lower elevation than the second reservoir and / or a rigid tank which is mechanically isolated from the water submerging the tank and / or a tank on or above the surface of the water body and / or a tank located on land.
  • the present figure shows the present embodiment at or near a fully discharged, steady state.
  • “2” may comprise an underwater second reservoir, which may comprise low density liquid and water inside an underwater tank.
  • the low density liquid may be physically separate from the water by a physical barrier or separator (“S”).
  • S The physical barrier or separator may enable low density liquid to exchange pressure with the water, while ensuring the water and low density liquid are physically separate or not in direct contact.
  • the physical barrier or separator may be rigid, or flexible, or a combination thereof.
  • the physical separation or barrier may comprise a membrane.
  • the physical barrier or separator may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water.
  • Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “6” may comprise a third reservoir, which, in the present figure, comprises storage for displaced water and may be located on land.
  • “1” may comprise a first reservoir, which may comprise storage for low density liquid and may be located at a greater elevation than a second reservoir. Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”).
  • Electricity may be generated or discharged by allowing low density liquid in the second reservoir to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir.
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 55 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir into a separate water reservoir (third reservoir).
  • the third reservoir may comprise a tank at a higher elevation than the second reservoir and / or a tank which is at a lower elevation than the second reservoir and / or a rigid tank which is mechanically isolated from the water submerging the tank and / or a tank on or above the surface of the water body and / or a tank located on land.
  • the present figure shows the present embodiment at a state of storing electricity or charging, wherein electricity may be stored by powering a pump to transfer low density liquid from the first reservoir to the second reservoir, displacing water in the second reservoir.
  • “2” may comprise an underwater second reservoir, which may comprise low density liquid and water inside an underwater tank. In the second reservoir, the low density liquid may be physically separate from the water by a physical barrier or separator (“S”).
  • the physical barrier or separator may enable low density liquid to exchange pressure with the water, while ensuring the water and low density liquid are physically separate or not in direct contact.
  • the physical barrier or separator may be rigid, or flexible, or a combination thereof.
  • the physical barrier or separator may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water.
  • Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “6” may comprise a third reservoir, which, in the present figure, comprises storage for displaced water and may be located on land.
  • “1” may comprise a first reservoir, which may comprise storage for low density liquid and may be located at a greater elevation than a second reservoir. Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”).
  • Electricity may be generated or discharged by allowing low density liquid in the second reservoir to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir.
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • Figure 56 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir into a separate water reservoir (third reservoir).
  • the third reservoir may comprise a tank at a higher elevation than the second reservoir and / or a tank which is at a lower elevation than the second reservoir and / or a rigid tank which is mechanically isolated from the water submerging the tank and / or a tank on or above the surface of the water body and / or a tank located on land.
  • the present figure shows the present embodiment at or near a fully charged, steady state.
  • “2” may comprise an underwater second reservoir, which may comprise low density liquid and water inside an underwater tank.
  • the low density liquid may be physically separate from the water by a physical barrier or separator (“S”).
  • S physical barrier or separator
  • the physical barrier or separator may enable low density liquid to exchange pressure with the water, while ensuring the water and low density liquid are physically separate or not in direct contact.
  • the physical barrier or separator may be rigid, or flexible, or a combination thereof.
  • the physical barrier or separator may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water.
  • Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “6” may comprise a third reservoir, which, in the present figure, comprises storage for displaced water and may be located on land.
  • “1” may comprise a first reservoir, which may comprise storage for low density liquid and may be located at a greater elevation than a second reservoir. Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”). Electricity may be generated or discharged by allowing low density liquid in the second reservoir to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir.
  • a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”). Electricity may be generated or discharged by allowing low density liquid in the second reservoir to be displaced by water from the third reservoir, wherein water from the third reservoir dis
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • FIG. 57 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (second reservoir) to displace water inside said second reservoir into a separate water reservoir (third reservoir).
  • the third reservoir may comprise a tank at a higher elevation than the second reservoir and / or a tank which is at a lower elevation than the second reservoir and / or a rigid tank which is mechanically isolated from the water submerging the tank and / or a tank on or above the surface of the water body and / or a tank located on land.
  • the present figure shows the present embodiment at an electricity generating or discharging state. Electricity may be generated by allowing low density liquid to be displaced from the second reservoir, through a pipe, into a generator, generating electricity, and into the first reservoir.
  • Low density liquid in the second reservoir may be allowed to be displaced by water. Said allowing may involve opening a valve (“5”) in a low density liquid pipe.
  • “2” may comprise an underwater second reservoir, which may comprise low density liquid and water inside an underwater tank.
  • the low density liquid may be physically separate from the water by a physical barrier or separator (“S”).
  • the physical barrier or separator may enable low density liquid to exchange pressure with the water, while ensuring the water and low density liquid are physically separate or not in direct contact.
  • the physical barrier or separator may be rigid, or flexible, or a combination thereof.
  • the physical barrier or separator may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • Said separator or barrier may prevent direct contact between the low density liquid and water and / or may provide a physical separation between the low density liquid and water. Said separator or barrier may allow the low density liquid to displace the water, while, for example, preventing or minimizing direct contact between the water and the low density liquid.
  • “6” may comprise a third reservoir, which, in the present figure, comprises storage for displaced water and may be located on land.
  • “1” may comprise a first reservoir, which may comprise storage for low density liquid and may be located at a greater elevation than a second reservoir.
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”). Electricity may be generated or discharged by allowing low density liquid in the second reservoir to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir.
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • FIG. 58 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (“2”) (second reservoir) to displace water inside said second reservoir into a separate water reservoir (“8”) (third reservoir).
  • the second reservoir may comprise an underwater rigid tank which may contain both low density liquid and water.
  • low density liquid may be stored in a sub-reservoir or sub-tank (“10”) which may comprise an expandable or collapsible structure, such as a bladder tank or piston or a combination thereof. Said sub-tank may be employed to prevent direct contact between low density liquid and water in the second reservoir.
  • the leaked low density liquid may remain inside this rigid tank or rigid containment structure, preventing exposure of the low density liquid to the surrounding environment.
  • Said sub-tank may be considered a physical barrier or separator, and may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • the present figure shows the present embodiment at a near fully discharged state.
  • the third reservoir which may be connected to the second reservoir using a pipe, may comprise nearby ocean water, or a water tank at pressure equilibrium with the ocean, or a rigid water tank mechanically isolated from nearby ocean and at similar pressure to the hydrostatic pressure of the nearby ocean, or a water tank on or near the ocean surface, or a water tank on land. If the third reservoir is at pressure equilibrium with the surrounding ocean and / or the density of the liquid inside the third reservoir is close to the density of ocean water, the third reservoir may be located at any elevation relative to the second reservoir. For example, the third reservoir may be located at the same elevation as or similar elevation to the second reservoir, as is shown in the present figure. For example, the third reservoir may be located at a deeper depth or lower elevation than the second reservoir.
  • the third reservoir may be located at a shallower depth or greater elevation than the second reservoir.
  • the third reservoir may be located on land.
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”).
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”), specifically the low density liquid second reservoir sub-tank (“10”), and displace water from the second reservoir through a pipe (“9”) to a third reservoir (“8”).
  • Electricity may be generated or discharged by allowing low density liquid in the second reservoir, specifically the low density liquid second reservoir sub-tank (“10”), to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir (“1”).
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • An electricity storage system with a surface tank (‘1’), an underwater rigid tank (‘2’), a bladder sub-tank configured to store low density liquid (‘10’), and an interconnected external bladder tank configured to store water (‘8’).
  • FIG 59 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (“2”) (second reservoir) to displace water inside said second reservoir into a separate water reservoir (“8”) (third reservoir).
  • the second reservoir may comprise an underwater rigid tank which may contain both low density liquid and water.
  • low density liquid may be stored in a sub-reservoir or sub-tank (“10”) which may comprise an expandable or collapsible structure, such as a bladder tank or piston or a combination thereof.
  • Said sub-tank may be employed to prevent direct contact between low density liquid and water in the second reservoir.
  • the leaked low density liquid may remain inside this rigid tank or rigid containment structure, preventing exposure of the low density liquid to the surrounding environment.
  • Said sub-tank may be considered a physical barrier or separator, and may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • the present figure shows the present embodiment storing electricity or ‘charging’, wherein low density liquid is pumped from the first reservoir to the second reservoir, displacing water from the second reservoir into the third reservoir.
  • the third reservoir which may be connected to the second reservoir using a pipe, may comprise nearby ocean water, or a water tank at pressure equilibrium with the ocean, or a rigid water tank mechanically isolated from nearby ocean and at similar pressure to the hydrostatic pressure of the nearby ocean, or a water tank on or near the ocean surface, or a water tank on land. If the third reservoir is at pressure equilibrium with the surrounding ocean and / or the density of the liquid inside the third reservoir is close to the density of ocean water, the third reservoir may be located at any elevation relative to the second reservoir. For example, the third reservoir may be located at the same elevation as or similar elevation to the second reservoir, as is shown in the present figure. For example, the third reservoir may be located at a deeper depth or lower elevation than the second reservoir.
  • the third reservoir may be located at a shallower depth or greater elevation than the second reservoir.
  • the third reservoir may be located on land.
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”).
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”), specifically the low density liquid second reservoir sub-tank (“10”), and displace water from the second reservoir through a pipe (“9”) to a third reservoir (“8”).
  • Electricity may be generated or discharged by allowing low density liquid in the second reservoir, specifically the low density liquid second reservoir sub-tank (“10”), to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir (“1”).
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • the present embodiment storing electricity (‘charging’).
  • Low density liquid is pumped (‘4’) from the surface tank (‘ 1 ’), through a pipe (‘3’), to the underwater rigid tank (‘2’), displacing water in the underwater rigid tank (‘2’).
  • the displaced water travels through a pipe (‘9’) into the external bladder tank (‘8’).
  • Figure 60 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (“2”) (second reservoir) to displace water inside said second reservoir into a separate water reservoir (“8”) (third reservoir).
  • the second reservoir may comprise an underwater rigid tank which may contain both low density liquid and water.
  • low density liquid may be stored in a sub-reservoir or sub-tank (“10”) which may comprise an expandable or collapsible structure, such as a bladder tank or piston or a combination thereof.
  • Said sub-tank may be employed to prevent direct contact between low density liquid and water in the second reservoir.
  • the leaked low density liquid may remain inside this rigid tank or rigid containment structure, preventing exposure of the low density liquid to the surrounding environment.
  • Said sub-tank may be considered a physical barrier or separator, and may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • the present figure shows the present embodiment at a near fully charged state.
  • the third reservoir which may be connected to the second reservoir using a pipe, may comprise nearby ocean water, or a water tank at pressure equilibrium with the ocean, or a rigid water tank mechanically isolated from nearby ocean and at similar pressure to the hydrostatic pressure of the nearby ocean, or a water tank on or near the ocean surface, or a water tank on land. If the third reservoir is at pressure equilibrium with the surrounding ocean and / or the density of the liquid inside the third reservoir is close to the density of ocean water, the third reservoir may be located at any elevation relative to the second reservoir. For example, the third reservoir may be located at the same elevation as or similar elevation to the second reservoir, as is shown in the present figure. For example, the third reservoir may be located at a deeper depth or lower elevation than the second reservoir.
  • the third reservoir may be located at a shallower depth or greater elevation than the second reservoir.
  • the third reservoir may be located on land.
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”).
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”), specifically the low density liquid second reservoir sub-tank (“10”), and displace water from the second reservoir through a pipe (“9”) to a third reservoir (“8”).
  • Electricity may be generated or discharged by allowing low density liquid in the second reservoir, specifically the low density liquid second reservoir sub-tank (“10”), to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir (“1”).
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • FIG. 61 An energy storage system which stores electricity by pumping low density liquid into an underwater tank (“2”) (second reservoir) to displace water inside said second reservoir into a separate water reservoir (“8”) (third reservoir).
  • the second reservoir may comprise an underwater rigid tank which may contain both low density liquid and water.
  • low density liquid may be stored in a sub-reservoir or sub-tank (“10”) which may comprise an expandable or collapsible structure, such as a bladder tank or piston or a combination thereof.
  • Said sub-tank may be employed to prevent direct contact between low density liquid and water in the second reservoir.
  • the leaked low density liquid may remain inside this rigid tank or rigid containment structure, preventing exposure of the low density liquid to the surrounding environment.
  • Said sub-tank may be considered a physical barrier or separator, and may be removable or replaceable or adjustable or a combination thereof, which may facilitate operations, or maintenance, or efficiency, or system longevity, or cost, or a combination thereof.
  • the present figure shows the present embodiment generating electricity or ‘discharging’. For example, discharging may involve allowing low density liquid in the second reservoir to be displaced by water in the third reservoir, and wherein said low density liquid is displaced into a pipe, into a generator, generating electricity, and into the first reservoir.
  • the third reservoir which may be connected to the second reservoir using a pipe, may comprise nearby ocean water, or a water tank at pressure equilibrium with the ocean, or a rigid water tank mechanically isolated from nearby ocean and at similar pressure to the hydrostatic pressure of the nearby ocean, or a water tank on or near the ocean surface, or a water tank on land. If the third reservoir is at pressure equilibrium with the surrounding ocean and / or the density of the liquid inside the third reservoir is close to the density of ocean water, the third reservoir may be located at any elevation relative to the second reservoir. For example, the third reservoir may be located at the same elevation as or similar elevation to the second reservoir, as is shown in the present figure. For example, the third reservoir may be located at a deeper depth or lower elevation than the second reservoir.
  • the third reservoir may be located at a shallower depth or greater elevation than the second reservoir.
  • the third reservoir may be located on land.
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”) and displace water from the second reservoir through a pipe (“7”) to the third reservoir (“6”).
  • Electricity may be stored by powering a pump (“4”) to pump low density liquid from the first reservoir through a pipe (“3”) to the second reservoir (“2”), specifically the low density liquid second reservoir sub-tank (“10”), and displace water from the second reservoir through a pipe (“9”) to a third reservoir (“8”).
  • Electricity may be generated or discharged by allowing low density liquid in the second reservoir, specifically the low density liquid second reservoir sub-tank (“10”), to be displaced by water from the third reservoir, wherein water from the third reservoir displaces low density liquid from the second reservoir through a pipe (“3”), through a generator (“4”), generating electricity, and into the first reservoir (“1”).
  • the pump and generator may comprise the same unit(s) which can reversibly function as a pump and a generator, which may comprise a hydraulic power recovery turbine (HPRT).
  • HPRT hydraulic power recovery turbine
  • the pressure inside the second reservoir may be close to or about equivalent to the hydrostatic pressure of the ocean at the underwater depth of the second reservoir.
  • the present embodiment generating electricity (‘discharging’).
  • Water in the external bladder tank (‘8’) is allowed to displace low density liquid in the underwater rigid tank (‘2’).
  • the displaced low density liquid travels through a pipe (‘3’), through a generator (‘4’), to the surface tank (‘1’).
  • Figure 62 The present figure may comprise a similar embodiment to Figures 58 - 61.
  • the present figure may show the present embodiment as a near fully discharged state.
  • the present figure may employ a third reservoir comprising nearby ocean water or open ocean water.
  • the sub tank within the second reservoir (“10”), the second reservoir, and the external water pipe connected to the second reservoir (“11”) may be configured such that when low density liquid is pumped into “10”, water displaced from the second reservoir exits the second reservoir in a manner which prevents low density liquid from exiting the second reservoir in the event of a release or leak of low density liquid.
  • said configuration may comprise a pipe and / or tank setup such that a liquid or material exiting the tank must have a density greater than or equal to or close to the density of water.
  • said configuration may involve the external water pipe “11” possessing an outlet or external outlet which faces toward the seafloor or faces downward or a bend which faces downward.
  • said configuration may involve the external water pipe “11” possessing a pipe inside the underwater tank which has a bend upward and / or faces upward and / or faces toward the sea surface and / or faces away from the seafloor and / or possesses an opening inside the underwater tank which faces upward.
  • said configuration may involve the external water pipe containing a chemical or reagent or material which will swell or absorb low density liquid or react with low density liquid when in presence or contact with low density liquid, which may occur in the event of, for example, a low density liquid leak or release from the sub-tank, which may, for example, trigger the closure of a valve inside the pipe or passively clog or close the pipe or a combination thereof in the event of a low density liquid leak or release from the sub-tank.
  • “11” may be removable or replaceable.
  • the second reservoir internal sub-tank, or the external water pipe, or the third reservoir (if comprising a tank), or a combination thereof may be removable, or replicable.
  • second reservoir internal sub-tank, or the external water pipe, or the third reservoir (if comprising a tank), or a combination thereof may be removed or replaced while the second storage reservoir remains in operation.
  • second reservoir internal sub-tank, or the external water pipe, or the third reservoir (if comprising a tank), or a combination thereof may be removed or replaced while the second storage reservoir remains installed.
  • second reservoir internal sub-tank, or the external water pipe, or the third reservoir (if comprising a tank), or a combination thereof may be removed or replaced or maintained while one or more or components remain installed and / or operating, which may include one or more or a combination of the previously described components or other parts of the present invention described herein.
  • the underwater rigid tank (‘2’) is in direct fluid communication with the adjacent deep sea ocean water by a pipe (‘11’).
  • the present embodiment at a nearly fully discharged state.
  • FIG 63 The present figure may comprise the embodiment described in the description of Figure 62.
  • the present figure shows the present embodiment at a state of ‘charging’ or storing energy or electricity.
  • Charging may involve pumping low density liquid from the first reservoir to the second reservoir, displacing water in the second reservoir. Water may exit the second reservoir during said displacing such that, even if even the low density liquid leaks from the internal sub-tank within the second reservoir, the low density liquid may remain in the second reservoir.
  • the present embodiment storing electricity (‘charging’).
  • Low density liquid is pumped (‘4’) from the surface tank (‘ 1 ’), through a pipe (‘3’), to the underwater rigid tank (‘2’), displacing ocean water from the underwater rigid tank (‘2’).
  • the displaced ocean water travels through a pipe (‘11’) into the ocean adjacent the underwater rigid tank (‘2’).
  • Figure 64 The present figure may comprise the embodiment described in the description of Figure 62. The present figure shows the present embodiment at a nearly fully charged state.
  • Figure 65 The present figure may comprise the embodiment described in the description of Figure 62.
  • the present figure shows the present embodiment at a state of ‘discharging’ or generating energy or generating electricity.
  • Discharging may involve allowing low density liquid to be displaced from the second reservoir into a pipe, through a generator, generating electricity, and into the first reservoir.
  • Said displacing may involve ocean water passing through a pipe (“11”) into the second reservoir. Water may exit the second reservoir during said displacing such that, even if even the low density liquid leaks from the internal sub-tank within the second reservoir, the low density liquid may remain in the second reservoir.
  • the present embodiment generating electricity (‘discharging’).
  • Ocean water adjacent to the underwater tank in direct fluid communication with the underwater rigid tank (‘2’) through a pipe (‘11’) is allowed to displace low density liquid in the underwater rigid tank (‘2’).
  • the displaced low density liquid travels through a pipe (‘3’), through a generator (‘4’), to the surface tank (‘1’).
  • Figure 66 An energy storage embodiment with a second reservoir and / or third reservoir with a containment cover or containment barrier (“CB” or “CCB”).
  • CB may comprise a cover located over or above one or more components of the system.
  • Said CB may comprise a cover located over or above components of the system which may hold or contain low density liquid. In the event low density liquid escapes from the second reservoir, the low density liquid may float upward, due to, for example, its low density than the water, and may be captured by the CB.
  • FIG. 67 An energy storage embodiment with a second reservoir and / or third reservoir with a containment cover or containment barrier (“CB” or “CCB”).
  • CB may comprise a cover located over or above one or more components of the system.
  • Said CB may comprise a cover located over or above components of the system which may hold or contain low density liquid. In the event low density liquid escapes from the second reservoir, the low density liquid may float upward, due to, for example, its low density than the water, and may be captured by the CB.
  • FIG. 68 An energy storage embodiment with a second reservoir and / or third reservoir with a containment cover or containment barrier (“CB” or “CCB”).
  • CB may comprise a cover located over or above one or more components of the system.
  • Said CB may comprise a cover located over or above components of the system which may hold or contain low density liquid. In the event low density liquid escapes from the second reservoir, the low density liquid may float upward, due to, for example, its low density than the water, and may be captured by the CB.
  • FIG. 69 An energy storage embodiment with a second reservoir and / or third reservoir with a containment cover or containment barrier (“CB” or “CCB”).
  • CB may comprise a cover located over or above one or more components of the system.
  • Said CB may comprise a cover located over or above components of the system which may hold or contain low density liquid.
  • the low density liquid may float upward, due to, for example, its low density than the water, and may be captured by the CB.
  • “S” may comprise a separator or barrier, which may prevent or minimize the physical or direct contact between low density liquid and water within the second reservoir.
  • Figure 70 An energy storage system which stores electricity by pumping low density liquid into a sub-tank (“5”) within ta second reservoir (“2”) to displace water inside said second reservoir.
  • the second reservoir may comprise a rigid tank or rigid containment structure, which may surround or contain a sub-tank (“5”) configured to store low density liquid.
  • Said sub-tank may comprise an expandable or collapsible tank.
  • Said sub-tank may be situated above a water port or hole or pipe or the outlet or a combination thereof to, for example, ensure low density liquid remains in the second reservoir in the event of a leak or accidental release of low density liquid.
  • Said water port or hole or pipe or the outlet or a combination thereof may be employed to enable displaced water during the ‘storing’ of electricity to exit the second reservoir; and / or enable water to enter the second reservoir to displace low density liquid during the discharging or generating of electricity.
  • the sub-tank may comprise a membrane or membrane-like structure.
  • a rigid tank or rigid containment structure may surround the sub-tank and / or cover the top portion of the sub tank.
  • An example characteristic of the rigid tank or rigid containment structure may comprise the ability to control the entering or exiting of water or other liquids or substances from the second reservoir, which may include, but is not limited to, the ability to open or close a valve or port which may enable or disable or both the flow of water, or other liquids or other substances to and / or from the second reservoir.
  • the present figure shows the present embodiment ‘charging’/. Said charging may involve pumping low density liquid from the first reservoir to the second reservoir, displacing water from the second reservoir with the low density liquid.
  • Figure 71 An energy storage system which stores electricity by pumping low density liquid into a sub-tank (“5”) within a second reservoir (“2”) to displace water inside said second reservoir.
  • the second reservoir may comprise a rigid tank or rigid containment structure, which may surround or contain a sub-tank (“5”) configured to store low density liquid.
  • Said sub-tank may comprise an expandable or collapsible tank.
  • Said sub-tank may be situated above a water port or hole or pipe or the outlet or a combination thereof to, for example, ensure low density liquid remains in the second reservoir in the event of a leak or accidental release of low density liquid.
  • Said water port or hole or pipe or the outlet or a combination thereof may be employed to enable displaced water during the ‘storing’ of electricity to exit the second reservoir; and / or enable water to enter the second reservoir to displace low density liquid during the discharging or generating of electricity.
  • a rigid tank or rigid containment structure may surround the sub-tank and / or cover the top portion of the sub-tank.
  • An example characteristic of the rigid tank or rigid containment structure may comprise the ability to control the entering or exiting of water or other liquids or substances from the second reservoir, which may include, but is not limited to, the ability to open or close a valve or port which may enable or disable or both the flow of water, or other liquids or other substances to and / or from the second reservoir.
  • the present figure shows the present embodiment at a nearly fully charged state.
  • Figure 72 An energy storage system which stores electricity by pumping low density liquid into a sub-tank (“5”) within a second reservoir (“2”) to displace water inside said second reservoir.
  • the second reservoir may comprise a rigid tank or rigid containment structure, which may surround or contain a sub-tank (“5”) configured to store low density liquid.
  • Said sub-tank may comprise an expandable or collapsible tank.
  • Said sub-tank may be situated above a water port or hole or pipe or the outlet or a combination thereof to, for example, ensure low density liquid remains in the second reservoir in the event of a leak or accidental release of low density liquid.
  • Said water port or hole or pipe or the outlet or a combination thereof may be employed to enable displaced water during the ‘storing’ of electricity to exit the second reservoir; and / or enable water to enter the second reservoir to displace low density liquid during the discharging or generating of electricity.
  • a rigid tank or rigid containment structure may surround the sub-tank and / or cover the top portion of the sub-tank.
  • An example characteristic of the rigid tank or rigid containment structure may comprise the ability to control the entering or exiting of water or other liquids or substances from the second reservoir, which may include, but is not limited to, the ability to open or close a valve or port which may enable or disable or both the flow of water, or other liquids or other substances to and / or from the second reservoir.
  • the present figure shows the present embodiment discharging or generating electricity.
  • Discharging or generating electricity may involve low density liquid from the second reservoir being displaced into a pipe, through a generator, generating electricity and into the first reservoir.
  • the displacement of low density liquid from the second reservoir may be allowed by opening a valve near or within the pump or generator or a valve near or within the second reservoir tank or a combination thereof.
  • the displacement of low density liquid in the second reservoir may comprise water entering the second reservoir and displacing the low density liquid in the second reservoir.
  • Figure 73 An energy storage system which stores electricity by pumping low density liquid into a sub-tank (“5”) within a second reservoir (“2”) to displace water inside said second reservoir.
  • the second reservoir may comprise a rigid tank or rigid containment structure, which may surround or contain a sub-tank (“5”) configured to store low density liquid.
  • Said sub-tank may comprise an expandable or collapsible tank.
  • Said sub-tank may be situated above a water port or hole or pipe or the outlet or a combination thereof to, for example, ensure low density liquid remains in the second reservoir in the event of a leak or accidental release of low density liquid.
  • Said water port or hole or pipe or the outlet or a combination thereof may be employed to enable displaced water during the ‘storing’ of electricity to exit the second reservoir; and / or enable water to enter the second reservoir to displace low density liquid during the discharging or generating of electricity.
  • a rigid tank or rigid containment structure may surround the sub-tank and / or cover the top portion of the sub-tank.
  • An example characteristic of the rigid tank or rigid containment structure may comprise the ability to control the entering or exiting of water or other liquids or substances from the second reservoir, which may include, but is not limited to, the ability to open or close a valve or port which may enable or disable or both the flow of water, or other liquids or other substances to and / or from the second reservoir.
  • the present figure shows the present embodiment at a nearly fully discharged state.
  • Figure 74 The present figure shows the present embodiment charging or storing electricity.
  • the present figure shows an embodiment where the first reservoir (“1”) and / or pump (“4”) and / or generator (“4”) is located underwater at a higher elevation or lesser water depth than the second reservoir.
  • the first reservoir may comprise a rigid tank or a bladder tank.
  • the first reservoir is shown as a rigid tank.
  • a subsea power cable (“15”) connects the pump and / or generator (“4”) to electricity power sources, and / or electricity demand sources, and / or an electricity grid.
  • Electricity power sources, and / or electricity demand sources, and / or an electricity grid, which may include transmission infrastructure, may be represented by “13” and “14” in the present figure and may be located on land or underwater.
  • the subsea power cable may interconnect the present energy storage system with offshore power sources, such as, for example, including, but not limited to, one or more or a combination of the following: offshore wind, offshore solar, and offshore rigs, offshore generating, or other power sources.
  • the subsea power cable may interconnect the present energy storage system with offshore demand sources, such as, for example, including, but not limited to, offshore pipelines, offshore transmission stations, offshore compression stations, offshore drilling, heated flow lines, offshore oil rigs, offshore production systems, hydrogen production, ammonia production, CO2 conversion, gas processing facilities, and / or other energy consumption sources.
  • offshore demand sources such as, for example, including, but not limited to, offshore pipelines, offshore transmission stations, offshore compression stations, offshore drilling, heated flow lines, offshore oil rigs, offshore production systems, hydrogen production, ammonia production, CO2 conversion, gas processing facilities, and / or other energy consumption sources.
  • the subsea power cable may interconnect the present energy storage system with on-shore energy demand and on-shore power production sources, which may include, but are not limited to, one or more or a combination of the following: industrial electricity demand, commercial electricity demand, residential electricity demand, transportation electricity demand, renewable power sources, residential power sources, electricity grid load balancing, electricity grid services, on shore solar plant, on-shore wind, on-shore hydropower, on-shore combustion power generation, hydrogen production, storing excess renewable electricity, discharging electricity during peak demand or when intermittent renewables are underproducing power.
  • the present figure may show an energy storage system which stores electricity by pumping low density liquid into a sub-tank (“5”) within a second reservoir (“2”) to displace water inside said second reservoir.
  • the present embodiment leverages multiple aspects of the technical limitations of offshore technologies, and the geography of many offshore regions.
  • the offshore seafloor in most of the world is relatively shallow within 10 miles, or 20 miles, or 30 miles, or 40 miles or 50 miles, or 60 miles or 70 miles, or 80 miles, or 90 miles, or 100 miles or a combination thereof of shore.
  • Relatively shallow water depth may comprise a water depth less deep than 1,000 meters, or 900 meters, or 800 meters, or 700 meters, or 600 meters, or 500 meters, or 400 meters, or 300 meters, or 200 meters, or 100 meters or a combination thereof.
  • said relatively shallow water eventually reaches a precipitous ledge or continental shelf, which drops to a water depth of 1,500 meters, or 2,000 meters, or 2,500 meters, or 3,000 meters, or even greater depths.
  • the present embodiment places the first reservoir and / or pump and generator at a near said ledge or continental shelf, which may minimize the length of the pipeline from the first reservoir to the second reservoir. Minimizing the length of the pipeline increases round-trip energy efficiency and reduces capital cost.
  • the pump and / or generator may be interconnected to a power source or power demand or an electricity grid or a combination thereof by a subsea power cable.
  • Subsea power cables are least expensive and / or simplest to install on relatively shallow and / or relatively flat subsea terrain.
  • the subsea cable in the present may be installed on relatively shallow and / or relatively flat subsea terrain.
  • Modem day offshore wind farms require relatively shallow water depths, generally less than 1,000 meters in water depth, to be economically viable.
  • the present embodiment enables the present invention to be integrated with current day offshore wind farms by being located relatively close to shallow water ideal for offshore wind farms.
  • the present invention may integrate with pre-existing or pre-planned subsea power cables or power transmission infrastructure.
  • the present invention may improve the economics of said technologies and other technologies, facilitating the construction of the subsea power infrastructure and / or the present invention. For example, offshore Virginia, North Carolina, Delaware, and Maryland (all locations with proposed offshore wind farms) possess shallow water and a nearby precipitous ledges and / or continental shelf.
  • the only ‘shore crossing infrastructure’ in the present embodiment may be a subsea power cable and related transmission interconnections and infrastructure.
  • the minimal ‘shore crossing’ and ‘on- shore’ infrastructure of the present embodiment may reduce the required permitting and / or approvals and / or timeline and / or regulatory bodies. Additionally, the lack of tanks or generators on-shore may enable the present embodiment to occupy less onshore land and / or may enable the present embodiment to be less visually obvious and / or make the present embodiment more visually appealing
  • the first reservoir and / or pump and / or generator may be located at a water depth sufficiently deep to be minimally exposed to ocean waves and / or ocean weather.
  • the first reservoir and / or pump and / or generator may be located at a water depth sufficiently shallow to enable a significant elevation difference between the first and second reservoirs.
  • a significant elevation difference may comprise an elevation or depth difference greater than or equal to 500 meters, or 1,000 meters, or 1,500 meters, or 2,000 meters.
  • it may be advantageous for the first reservoir and / or pump and / or generator may be located at a water depth sufficiently shallow to enable professional divers and / or professional diving vessels access or convenient access for monitoring and / or maintenance.
  • the present embodiment possesses practically limitless land area and / or geographic area for energy storage.
  • the amount of subsea seafloor with suitable geography vastly exceeds the seafloor land area required for multi-hour, or multi-day, or even multi-month electricity storage using the present embodiment.
  • Figure 75 The present figure comprises the same embodiment as Figure 74. The present figure shows the present embodiment at a nearly fully charged state.
  • Figure 76 The present figure comprises the same embodiment as Figure 74. The present figure shows the present embodiment discharging or generating electricity.
  • Figure 77 The present figure comprises the same embodiment as Figure 74. The present figure shows the present embodiment at a nearly fully discharged state.
  • FIG. 78 The present figure shows the present embodiment charging or storing electricity.
  • the present figure shows an embodiment where the first reservoir (“1”) and / or pump (“4”) and / or generator (“4”) is located in a floating vessel (“16”).
  • Said floating vessel may comprise a carrier, or a carrier retrofihed to enable greater unloading or loading flow rates than conventional carriers, or a specially designed carrier, or a combination thereof.
  • Said carrier may comprise a ship, such as, for example, an LPG carrier.
  • Said floating vessel may be interconnected to a subsea power cable and / or subsea low density liquid pipeline using or facilitated by one or more buoys.
  • the present figure may show the low density liquid pipeline interconnect buoy as “L” and the subsea cable electricity interconnect buoy as “X”.
  • L low density liquid pipeline interconnect buoy
  • X subsea cable electricity interconnect buoy
  • One or more or multiple or a combination of subsea pipelines, floating vessels, buoys, subsea tanks, or subsea tanks may be employed.
  • Floating vessels may be connectable or disconnectable or both. Floating vessels may be connectable or disconnectable to each other. Floating vessels may be connectable or disconnectable to or from floating buoys. For example, said floating vessels may be added or removed (connected or disconnected) when more or less energy storage or power capacity or both is required. Floating vessels may be transferred between one or more installations or projects to, for example, optimize required resources. For example, in some regions, greater electricity storage or power capacity may be required during certain time periods or seasons and / or less electricity storage or power capacity may be required during certain other time periods or seasons. Floating vessels may be transferred to and added to some regions during time periods of greater demand. Floating vessels may be disconnected and / or transferred away during time periods of lesser demand.
  • Floating vessels may be transferred from regions of lesser demand to regions of greater demand as needed. For example, a futures market or spot market or both may be created to lease floating vessels. Floating vessels may be employed as LPG carriers or other forms of carriers when demand for energy storage is low. In some instances, it may be desirable for one or more of the floating vessels and / or the low density liquid and / or a portion of the low density liquid to be leased by the project operator or owner instead of, for example, outright owned.
  • Floating vessels may disconnect to avoid severe weather, such as hurricanes. Floating vessels may be disconnected for maintenance. Floating vessels may be updated or replaced over time. For example, new technology advances or application needs or performance needs may be integrated into floating vessels as a retrofit or new floating vessels may be constructed or both. Floating vessels may be disconnected or connected due to changes in demand.
  • Floating vessels may exist in multiple forms.
  • a floating vessel may comprise a low density liquid storage unit.
  • a floating vessel may comprise both a low density liquid storage unit and the pump and / or generator.
  • a floating vessel may comprise a pump and / or generator.
  • Floating vessels of multiple forms may be combined or integrated as needed. Floating vessels may be changed or exchanged or integrated differently or possess updated configurations or a combination thereof, which may be simple to conduct in response to, for example, changing needs from one or more application.
  • a floating vessel connection buoy may contain an anchor connection or similar device to enable the floating vessel to remain in a general position without or with minimal need for a dynamic positioning system.
  • floating vessels may enable practically unlimited energy storage capacity.
  • floating vessels may be interconnected to increase energy storage capacity or power capacity or both.
  • the present embodiment may benefit from the current global capacity to construct and ship large scale floating carriers for LPG and other hydrocarbons and / or the available of floating carriers currently used for, for example, transporting hydrocarbons or offshore floating storage or both.
  • the use of floating vessels for the first reservoir and/or pump and / or generator may minimize the permitting and / or approvals required due to, for example, pre-existing permitting for carrier vessels.
  • the floating vessels may connect to the buoy by means of a Turret and Swivel Stack, which may be located on the floating vessel.
  • a turret and swivel stack may allows ships to rotate to face the wind or otherwise move while being interconnected a low density liquid pipeline and / or subsea electric cable.
  • Figure 79 The present figure comprises the embodiment in Figure 78.
  • the present figure shows the present embodiment at a nearly fully charged state.
  • Figure 80 The present figure comprises the embodiment in Figure 78.
  • the present figure shows the present embodiment discharging or generating electricity.
  • Figure 81 The present figure comprises the embodiment in Figure 78. The present figure shows the present embodiment at a nearly fully discharged state.
  • Figure 82 The present figure shows an embodiment where the first reservoir (“1”) and / or pump (“4”) and / or generator (“4”) is located in a floating vessel (“16”).
  • the present figure may show an embodiment where a floating vessel is capable of connecting to a subsea low density liquid pipeline (“3”) and a subsea electrical cable (“15”) by a combined buoy (“LX”).
  • Said combined buoy may be capable of connecting to and / or disconnecting from the floating vessel.
  • Said combined buoy may simplify the connection and / or disconnection process between the floating vessel and the combined buoy. In the present figure, the combined buoy may be shown disconnected from the floating carrier.
  • Figure 83 The present figure may comprise the same embodiment as Figure 82.
  • the combined buoy may be shown connected to the floating carrier.
  • Figure 84 An electricity storage system with a surface low density liquid tank (‘1’), an underwater rigid tank (‘2’), a bladder sub-tank configured to store low density liquid (‘10’), and a surface water tank (‘6’).
  • Figure 85 The present embodiment comprises the embodiment in Figure 84.
  • FIG. 86 The present embodiment comprises the embodiment in Figure 84. The present embodiment at a nearly fully discharged state.
  • Figure 87 The present embodiment comprises the embodiment in Figure 84.
  • An electricity storage system generating electricity (‘discharging’). Water in the surface water tank (‘6’) is transferred through a pipe (‘7’) into the underwater rigid tank (‘2’), where it is allowed to displace low density liquid in the underwater rigid tank (‘2’). The displaced low density liquid travels through a pipe (‘3’), through a generator (‘4’), to the surface tank (‘ 1 ’).
  • a low density liquid possessing a high vapor pressure may be employed as the low density liquid working fluid.
  • the system may be designed such that the underwater first reservoir is located at a water depth where the hydrostatic pressure of the water is close to the vapor pressure of the low density liquid at the temperature of the ocean water.
  • the tank installed may require less pressure difference resistance and may possess relatively thinner walls or may be lower cost than a tank storing the same liquid on the surface.
  • the temperature of water beneath the ocean may be relatively consistent depending on the climate and location, which my enable simpler prediction of low density liquid vapor pressure and / or design of tank pressure requirement and / or design water depth. Also, advantageously, the temperature of water beneath the ocean may be relatively consistently below a certain temperature range, which my enable simpler prediction of low density liquid vapor pressure and / or design of tank pressure requirement and / or design water depth.
  • liquid Ethane has a vapor pressure of 2807 kPa at 280°K and 4357 kPa at 300°K, which is equivalent to the hydrostatic pressure of water at about a 286 meter water depth and 445 meter water depth, respectively.
  • the first reservoir and / or pump and / or generator may be placed at, for example, a water depth deeper than 150 meters deep and less deep than 500 meters deep. Ethane remains at a liquid phase, rather than a supercritical phase, below its critical point of 305.322°K.
  • the temperature of ocean water at greater than 150 meter water depth, even in equatorial regions, is generally consistently less than 300°K, which may ensure ethane remains at a liquid phase rather than a supercritical phase.
  • Ethane has a density of 304 kg / m 3 at 300°K and 383 kg / m 3 at 280°K.
  • the present embodiment may be configured similar to the configuration of Figure 74. Alternatively, or additionally, the present embodiment may be configured similar to Figure 55, except where ‘1’, ‘6’, and / or ‘4’ are located underwater, although still at a higher elevation than ‘2’.
  • the present embodiment may be configured similar to other figures herein, although the first reservoir, or third reservoir, or pump/generator, or a combination thereof may be placed under the ocean in figures wherein the first reservoir, or third reservoir, or pump/generator, or a combination thereof may be shown above the ocean or on land adjacent to the ocean.
  • liquid ethane may be more abundant and / or less expensive than other low density liquid options.
  • liquid ethane may possess a lower density liquid than other low density liquid options.
  • the present embodiment pertains to an energy storage device employing a low density liquid and a high density liquid. Electricity is stored by displacing a high density liquid with a low density liquid and electricity is generated by allowing a high density liquid to displace a low density liquid.
  • said displacing occurs in an underwater storage reservoir configured to store both low density liquid and high density liquid.
  • An example high density liquid may include, but is not limited to, water.
  • An example low density liquid may include, but is not limited to, propane, butane, ethane, or LPG.
  • the underwater storage reservoir may comprise a rigid storage tank.
  • low density liquid comprises the hydraulic fluid employed in the pump and generator for generating electricity.
  • the low-density liquid floats above the high-density liquid.
  • the low density liquid may comprise the hydraulic fluid or working fluid employed in a pump or generator.
  • the present invention may employ a rigid underwater tank.
  • a rigid underwater tank or rigid underwater structure may be employed to contain or store at least a portion of the low-density liquid.
  • a rigid underwater tank may possess numerous advantages, which may include, but is not limited to, longer lifespan, lower risk of leaks or breaks, and resiliency to the elements.
  • o The energy storage system may continue to remain operational o Low density liquid may be safely removed and / or recoverable by allowing the electricity storage system to generate electricity or ‘discharge’ by allowing low density liquid to be transferred from the underwater reservoir to the reservoir near the surface. o Low density liquid may remain within the underwater storage region o Low density liquid may not leak or escape the underwater storage region
  • Low density liquid may be contained within a rigid region of the underwater storage tank, which may possess longer lasting or safer storage characteristics.
  • the present embodiment can employ density-based methods for passive risk mitigation, error correction, and emergency response, which may include, but are not limited to, the following: o
  • the present embodiment may employ a floating plug which possesses a density greater than low density liquid and less than water. Said plug may stop liquid flow into the low-density liquid pipe when the water level in the second reservoir is above a pre-defmed level. Said plug may prevent water from entering the low-density liquid pipe. Said plug may be employed to ensure a pre- defmed minimum volume of low-density liquid is present in the underwater storage reservoir. o If a barrier or separator breaks, within or o During charging, low density liquid may displace water downwards and out of the underwater tank through a bottom port in the underwater tank.
  • low density liquid may be prevented from coming into direct contact with the high density liquid by means of a physical separation.
  • Said physical separation may comprise a liquid with a density greater than the low density liquid and less than the high density liquid, while being insoluble in both the low density liquid and high density liquid.
  • Said physical separation may comprise a solid.
  • Said physical separation may comprise a barrier which possesses a density greater than low density liquid and less than high density liquid.
  • Said physical separation may comprise an impermeable material, such as a synthetic fabric or liner.
  • Said physical separation may be located below the low density liquid and above the water within the underwater storage reservoir or within a rigid underwater storage tank.
  • Said physical separation may be located within the underwater storage reservoir.
  • Said physical separation may be present within a tank which comprises rigid construction, which may comprise the underwater storage reservoir.
  • CB Containment Cover or Barrier or Boundary
  • the present invention may involve a containment cover or boundary or barrier (CB or CBB) over the underwater storage reservoir.
  • CB may capture low density liquid in the event of a leak or accidental release of low density liquid.
  • CB may be located over or above the underwater storage reservoir.
  • CB may comprise a liner or fabric or solid or a sheet or a combination thereof.
  • CB may be configured to funnel low density liquid (if captured) into particular regions of the CB to, for example, facilitate recovery of the LDL.
  • LDL or LDL hydrate or LDL composition may rise above the underwater reservoir and may be captured by or float into the CB.
  • CB may be floating above the underwater reservoir and may be anchored to the ocean bottom.
  • CB may be less dense than the ocean water, which may facilitate floatation. Alternatively, or additionally, the CB itself may be suspended or floating due to float(s) attached to the CB. In some embodiments, CB may cover or be above a surface area greater than or equal to the surface area of the underwater reservoir and / or underwater valves or connections. In some embodiments, CB may only cover or be above certain sections of the underwater reservoir, such as, for example, only covering the surface area above a connection or port. There may be more than one CB. For example, there may be a CB above certain connection points or ports. In some embodiments there may be redundant CBs. For example, a CB may cover a particular port, while another CB may cover the port and / or an entire section of the underwater reservoir.
  • CB may comprise materials which are compatible with water and / or the LDL.
  • CB may comprise materials that repel both water and LDL.
  • CB may comprise hydrophobic materials which absorb LDL.
  • CB may contain sensors or systems or mechanisms to determine if there is a LDL leak or if LDL has been captured by the CB.
  • said sensors may involve measuring the buoyancy force acting on a CB. If LDL is released and floats into a CB, the buoyancy force acting on the CB will increase, which may be measured by one or more sensors.
  • a sensor or indicator may involve a hydrophobic material which absorbs LDL. If LDL contacts said hydrophobic material, LDL may be absorbed, which may trigger the sensor and / or provide an indicator of the occurrence of a leak or accidental release of LDL.
  • a sensor may involve spectroscopy, which may provide indication of the presence of a new liquid other than ocean water, such as LDL.
  • a sensor may involve a float, which is less density than water and more density than LDL. If LDL leaks in sufficient quantities and collects in the CB, the float may begin to sink within a LDL layer which may form.
  • Other mechanisms for sensors may include, but is not limited to, conductivity, spectroscopy, spectrometric, visible color, absorbance, viscosity, pH, dissolution, polarity, dielectric constant, or a combination thereof.
  • a system may be employed to notify system operators of the occurrence of a LDL release.
  • Passive and / or active systems may be employed to remediate the problem or shut down the system or undergo pre-defmed procedures or undergo new procedures or a combination thereof autonomously or semi-autonomously or with the presence of a human system operator, or a combination thereof.
  • An example embodiment or configuration may comprise a rigid tank with a bladder tank inside to store LDL.
  • the remaining storage volume not occupied by the LDL bladder tank may be occupied by water.
  • the water may be interconnected to or comprise the surrounding or adjacent ocean.
  • the water may comprise water from an interconnected to a water reservoir.
  • Said water reservoir may comprise a surface water reservoir or an underwater reservoir.
  • An underwater water reservoir may comprise a tank containing water interconnected to the rigid tank via a pipe. The water reservoir may possess similar pressures or equilibrium pressure with the hydrostatic pressure of the ocean.
  • the LDL port in the rigid tank and/or the LDL bladder within the rigid tank may be located in the top portion of the rigid tank and/or away from the water port.
  • the water port maybe located at the bottom or in the bottom portion of the rigid tank and/or away from the LDL and/or the LDL port.
  • the water reservoir may contain freshwater or Deionized water if desired. Freshwater or deionized water may be advantageous to prevent corrosion inside the underwater rigid tank.
  • the LDL will remain in the rigid tank. LDL may be safely removed through the LDL port, which may involve the same procedure as is typically employed for discharging/generating electricity in the present invention
  • LDL may rise to the top of the rigid tank, which may prevent LDL from leaking and/or escaping to the surrounding water body or ensure LDL is contained within the system or ensure the LDL is salvageable for the system.
  • LDL hydrates may form, which may be significantly more dense than the LDL. If the underwater tank is full of LDL, the underwater reservoir may be designed to ensure the rigid tank water port clogs with LDL hydrates to prevent escape of LDL from the water port. Said design may include, but is not limited to, a filter or screen in the port which may intentionally clog or collect solids in the event LDL hydrates form.
  • LDL hydrates may sink to the bottom of the tank or float in the interface between water and the LDL
  • one or more valves may close.
  • the water pipe or port may possess a valve which closes.
  • the LDL port or pipe may possess a valve which closes.
  • the present embodiment possesses multiple redundancies.
  • the present embodiment may enable LDL to remain contained within a rigid structure or rigid tank, which may ensure the LDL does not escape into the surrounding ocean and / or may ensure LDL is recoverable of salvageable and / or the process is operational, even in the event one or more bladders or barriers fail or burst or break. Additionally, the present embodiment may enable the inside of the rigid tank to be in contact with a water with less corrosive species than ocean water.
  • the present invention may pertain to a gravitational energy storage system involving the displacement of water with a low-density liquid, wherein an underwater storage tank is floating above the ocean floor.
  • the floating underwater storage tank may be buoyant due to the floating underwater storage possessing a lower density or lower average density than the surrounding ocean water.
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be located at a higher elevation and configured to store a fluid which has a lower density than water
  • a second storage reservoir configured to be located at a lower elevation and configured to store a fluid which has a lower density than water and water;
  • a third storage reservoir configured to store water
  • electricity is generated or discharged by allowing water in the third reservoir to displace low density fluid in the second storage reservoir to the first storage reservoir.
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir is configured to store water and a low-density liquid.
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir is a rigid tank configured to store water and a low- density liquid.
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a low density liquid
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir is configured to store the water and the low density liquid and wherein the low density liquid has a density below the density of liquid water.
  • said physical barrier comprises a material with an average density less than liquid water and more than the low density liquid at a temperature greater than 3oC and less than 50oC at the same hydrostatic pressure.
  • the system of exemplary embodiment 1 further comprising a third reservoir operably connected to transfer water displaced by low density liquid during the storing of electricity from the second reservoir to the third reservoir.
  • the third reservoir comprises a liquid with a density which is within +/- 0.5%, or 1%, or 2%, or 3%, or 4%, or 5%, or 6%, or 7%, or 8%, or 9%, or 10% of the density of ocean water, which may be a liquid at a temperature greater than 3oC and less than 40oC at the same hydrostatic pressure
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be located at a higher elevation and configured to store a fluid which has a lower density than water
  • a second storage reservoir configured to be located at a lower elevation
  • a third storage reservoir configured to store water
  • the second storage reservoir is configured to store water and a low-density liquid.
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be located at a higher elevation and configured to store a fluid which has a lower density than water
  • a second storage reservoir configured to be located at a lower elevation and configured to store low density liquid and water
  • a third storage reservoir configured to store water
  • electricity is generated or discharged by allowing water in the third reservoir to displace low density fluid in the second storage reservoir to the first storage reservoir.
  • a system for storing or generating electricity comprising: [0396] a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir is configured to store water and a low-density liquid.
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir is configured to store water and a low-density liquid
  • low density liquid comprises the hydraulic fluid in the pump and generator
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir is configured to store water and low-density liquid
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • the pump, generator, and the first and second reservoir are operatively connected such that electricity is stored by displacing water inside the second storage reservoir by pumping low density fluid in the first storage reservoir to the second storage reservoir and electricity is generated or discharged by allowing the low density fluid in the second storage reservoir to return to the first storage reservoir;
  • the second storage reservoir is configured to store water and low-density liquid
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water
  • a second storage reservoir configured to be located below the surface of the body of water
  • the second storage reservoir contains a low density liquid - water liquid-liquid interface
  • CB Containment Cover or Containment Barrier
  • a system for storing or generating electricity comprising:
  • a first storage reservoir configured to be near the surface of a body of water and configured to store a fluid which has a lower density than water;
  • a second storage reservoir configured to be located below the surface of the body of water and configured to store a fluid which has a lower density than water;
  • the pump, generator, and the first and second reservoir are operatively connected such that electricity is stored by displacing water adjacent the second storage reservoir by pumping low density liquid in the first storage reservoir to the second storage reservoir and electricity is generated by allowing the low density fluid in the second storage reservoir to return to the first
  • An energy storage system comprising:
  • a surface tank A Subsea tank, A pipe, A pump, and A generator;
  • An energy storage system comprising:
  • a surface tank A Subsea tank, A pipe, A pump, and A generator;
  • Subsea tank contains a water - low density liquid interface
  • a rigid tank with a low density liquid and water configured to store LDL and water; and, [0449] A bladder tank configured to store water;
  • bladder tank is located at the same elevation as the rigid tank;
  • the location of the bladder tank and elevation of the bladder tank relative to the rigid tank may be virtually any elevation beneath the water body because the water inside the tank is at the same density as the water in the surrounding water body.
  • Bladder tank is sunk as a fully collapsed tank and may be connected to the rigid tank, via, for example, a pipe.
  • the rigid tank is sunk by flooding the rigid tank.
  • the bladder tank may be floating or sit on the ocean bottom.
  • the energy storage system may be charged when at a partially charged state.
  • the energy storage system may be charged when at a fully discharged state. • Note: The energy storage system may be discharged when at a partially charged or partially discharged state.
  • the energy storage system may be discharged when at a fully charged state.
  • the pressure of the water transferred to or from the surface water tank (‘inside water’) may be desirable for the pressure of the water transferred to or from the surface water tank (‘inside water’) to equal to the gravitational hydrostatic pressure of the water surrounding the pipes (‘outside water’).
  • the pressure of the inside water may be less than or greater than the outside water by the pressure tolerance of a subsea tank, or one or more components or parts in contact with inside water, or a combination thereof.
  • An example method to ensure the pressure of inside water and outside water is similar is to place a valve or pressure regulator between surface water tank(s) and subsea tank(s).
  • said valve or pressure regulator may be attached to or inside a pipeline connecting surface water tank(s) and subsea tank(s).
  • the pressure inside the second reservoir may differ from the pressure of the hydrostatic pressure surrounding or adjacent to the second reservoir by less than 10 PSI, or 15 PSI, or 20 PSI, or 1 atm, or 2 atm, or 3 atm, or 4 atm, or 5 atm, or 6 atm, or 7 atm, or 8 atm, or 9 atm, or 10 atm, or 11 atm, or 12 atm, or 15 atm, or 20 atm, or 30 atm, or 40 atm, or 50 atm, or 60 atm, or 70 atm, or 80 atm, or 90 atm, or 100 atm.
  • the low density liquid or the high density liquid may be enclosed in a bladder tank within a rigid underwater tank.
  • the water may be enclosed within a bladder tank inside the rigid underwater tank, while the low density liquid may float above said bladder tank.
  • the low density liquid may be enclosed within a bladder tank inside the rigid underwater tank, while the water may sink below or may be present below said bladder tank.
  • Water inside the rigid underwater tank may comprise or be fluid connected or may be in hydrostatic pressure equilibrium with adjacent or surrounding ocean water.
  • the separator or physical barrier may comprise a layer of a solid hydrate of low density liquid,.
  • Said solid hydrate may possess a density greater than low density liquid and less than water.
  • Said solid hydrate layer may inhibit further mixing or formation of hydrate.
  • the pump / generator in the present invention may comprise a Hydraulic Power Recovery Turbine (HPRT).
  • HPRTs may be currently employed as pump / generator in, including, but not limited to, the hydrocarbon transport, processing, and refining industries. HPRTs are known to be more energy efficient with lower viscosity of the working fluid.
  • the present invention may employ ultra-low viscosity liquids, such as liquid propane, liquid butane, or LPG, which may possess a substantially lower viscosity than water, which may enable the HPRT to possess a round trip efficiency greater than the round-trip efficiencies associated with water.
  • the surface water tank or the third reservoir configured to store water on the surface or at a higher elevation than the second reservoir may comprise a rigid tank or a bladder tank or a combination thereof.
  • the third reservoir configured to store water and / or located near, on, or above the ocean surface may comprise a bladder tank, which may be at a pressure in equilibrium with the pressure outside or adjacent to said third reservoir.
  • HPRTs can operate most efficiently at certain ranges of capacity utilization (flow rate) and pressure head. HPRTs are generally most efficient closer to their maximum capacity utilization and pressure head. There are multiple methods to ensure near maximum efficiency in the pump / generator, when, for example, employing HPRTs, which may include, but are not limited to, one or more or a combination of the following: o Multiple smaller HPRTs may be employed, wherein HPRTs which are running are run at or near maximum efficiency and / or maximum capacity (highest efficiency is near or at highest capacity). If the demand for storing power changes, the number and / or capacity of the HPRTs online or ‘on’ for storing power may be adjusted. If the demand for generating power changes, the number and / or capacity of the HPRTs online or ‘on’ for generating power may be adjusted. o If the energy requiring storing is less than the capacity of the HPRTs there may be a few options:
  • each of said lower capacity HPRTs may operate at near maximum efficiency and / or maximum capacity when in operation
  • fly-wheels or capacitors or Li-Ion batteries or other standard energy storage devices may be employed to fill in this relatively smaller storage need.
  • Said ‘other standard energy storage devices’ may be discharged to charge the liquid displacement energy storage technology by powering a pump (such as a HPRT) when desirable or may supply electricity directly to the grid or application or a combination thereof.
  • the floating subsea tank may be rigid or collapsible / expandable or a combination thereof.
  • the floating subsea tank may be suspended over the seafloor by tethers or anchors or attachment lines or other mechanisms.
  • the floating subsea tank may be designed to disconnect from its tether(s) and / or pipeline(s) as part of an emergency disconnect system.
  • Said emergency disconnect system may enable the subsea tank to float to the surface, which may enable to subsea tank to avoid rupture or other catastrophic failure, which may otherwise occur due to debris from an underwater landslide or other catastrophic event.
  • a floating subsea tank may enable the tank to be easier to implement when, for example, the seafloor is uneven or steep or otherwise challenging for the placement of a tank on the seafloor surface.
  • Installation of a floating subsea bladder tank may involve, for example: o 1) Sinking a fully collapsed bladder tank to the ocean floor o 2) Attaching bladder tank tethers and / or anchors to the ocean floor and / or to moorings or weights. Attaching LDL pipeline to the bladder tank o 3) Using the LDL pipeline, add LDL to the bladder tank, resulting in the bladder tank becoming buoyant.
  • the bladder tank may be floating above the ocean floor and / or suspended above the ocean floor due to, including, but not limited to, one or more or a combination of the following: tethers or anchors.
  • LDL pipeline may be placed or sunk to the ocean bottom while containing or full of LDL.
  • LDL pipeline may be weighted or attached to anchors or weights or a combination thereof to, for example, prevent the LDL pipeline from floating to the ocean surface.
  • LDL pipeline may be placed or sunk to the ocean bottom.
  • LDL pipeline may be flooded with ocean water during the sinking process. Once on the ocean bottom or once placed in the appropriate location, water in the LDL pipeline may be displaced with LDL by pumping LDL into the pipeline and / or allowing displaced ocean water to exit the pipeline. Displaced ocean water may exit the pipeline, for example, into the surrounding ocean or into a separate containment tank. Said separate containment tank, if employed may be temporary or permanent.
  • one or valves may be closed to, for example, prevent the escape of LDL to the surround ocean and / or prevent the intrusion of ocean water into the LDL pipeline.
  • said pipeline may be attached to an underwater tank or a floating underwater tank, when, for example, the pipeline is sufficiently full of LDL.
  • LDL pipeline may be weighted or attached to anchors or weights or a combination thereof to, for example, prevent the LDL pipeline from floating to the ocean surface.
  • the minimum volume or amount of LDL in the floating underwater tank may comprise the minimum amount of LDL required to ensure the floating underwater tank is buoyant.
  • One or more or a combination of components of the present invention may be located underground or partially underground.
  • the first storage reservoir which may comprise a rigid tank on land or underwater, may be located underground.
  • one or more or a portion of or a combination of pipes or valves or pumps or generators may be located underground or partially underground.
  • the second reservoir which may comprise an underwater rigid tank, may be located underground.
  • Placing one or more tanks or other components underground may conceal the tanks from public view, which may increase safety and / or reduce the potential eyesore of a tank. Placing one or more tanks or other components underground may increase the longevity of said tanks. Placing one or more tanks or other components underground may increase the system’s resilience to severe weather, natural disasters, or man-made risks.
  • ‘8’ may be buoyant, or neutrally buoyant, or may be at a greater density than the surrounding water body, or a combination thereof.
  • the density of a subsea tank may vary depending on the volume or amount of liquid stored in the tank.
  • LPG propane, butane, or other liquified gases, which may be employed as low density liquids, may be semi-refrigerated or partial refrigerated or refrigerated in the surface storage tanks.
  • the surface storage tanks or floating storage tanks or the first reservoir may be capable of greater carrying capacity or may be lower capital cost or a combination thereof.
  • the low density liquid may be stored at ambient temperatures and / or temperatures matching or near the temperature of the water surrounding the second storage reservoir and / or may be stored pressurized.
  • Refrigerated or semi-refrigerated or partially refrigerated or cooled vessels may comprise temperatures less than or equal to one or more or a combination of the following: 50°C, or 40°C, or 30°C, or 20°C, or 10°C, or 5°C, or, 0°C, or -10°C, or -20°C, or -30°C, or -40°C, or -50°C.
  • a configuration involving a subsea rigid tank configured to store water and LDL and a separate or interconnected bladder tank configured to stored water may be advantageous, due to, for example, including but not limited to, one or more or a combination of the following: o No need for a water pipeline to the surface or for a tank on the surface o Bladder tank underwater is storing primarily water, instead of LDL.
  • a bladder tank may possess a longer longevity or lifespan with water compared to LDL
  • a bladder tank configured for water may be less expensive or comprise less expensive materials than a bladder tank configured for LDL
  • a valve in the pipe connecting the bladder tank to the rigid tank may be closed, which may comprise an emergency shutdown procedure. If said valve fails to close, LDL in the rigid tank will naturally remain in the rigid tank, For example, LDL may remain in the rigid tank due to the location or configuration of the pipe connecting the rigid tank to the bladder tank.
  • the pressure inside the rigid tank will likely remain constant and the composition of the water inside the rigid tank may remain constant.
  • Bladder tank enables the rigid underwater tank to experience the same pressure inside the tank as the pressure outside the tank or the pressure of the surrounding hydrostatic pressure.
  • Some embodiments may involve a floating separator separating water from the LDL in an underwater tank
  • the round trip electrical efficiency may be greater than or equal to 30%, or 40%, or 50%, or 60%, or 70%, or 80%, or 90%
  • the present invention may contain multiple pipelines, surface tanks, subsea tanks, HPRT units or pump generator units, valves, other components or a combination thereof.
  • Rigid tank or rigid containment structure which may surround at least a portion or the top of an internal sub-reservoir or sub-tank, which may comprise a flexible structure or expandable or collapsible structure, such as a bladder.
  • Said rigid structure may comprise a steel tank or composite tank or a combination thereof.
  • the internal sub-tank may store water, while low density liquid may be stored in the rigid tank.
  • the low density liquid and the water are stored in internal sub-tank inside the rigid tank or rigid containment structure.
  • the ‘rigid containment structure’ may also or alternatively be a flexible structure
  • Dashed line in figure may indicate a labelling line.
  • the dashed line or dashed box may indicate a label only.
  • Dashed lines or dashed boxes may not be process elements in and of themselves.
  • the water depth of, for example, the second reservoir may be deeper than or equal to, one or more or a combination of the following: 200 meters, or 300 meters, or 400 meters, or 500 meters, or 600 meters, or 700 meters, or 800 meters, 900 meters, or 1,000 meters, 1,100 meters, or 1,200 meters, or 1,300 meters, or 1,400 meters, or 1,500 meters, or 1,600 meters, or 1,700 meters, 1,800 meters, or 1,900 meters, or 2,000 meters, 2,100 meters, or 2,200 meters, or 2,300 meters, or 2,400 meters, or 2,500 meters, or 2,600 meters, or 2,700 meters, 2,800 meters, or 2,900, or 3,000 meters • Note: o
  • the water reservoir may comprise a liquid of the same density as the surrounding or adjacent ocean water and in pressure equilibrium with the surrounding or adjacent ocean water.
  • a valve in a pipe interconnecting the water reservoir with the rigid tank may close, if desired.
  • Said valve may prevent low density liquid or other contents of the rigid tank or end-to-end system from leaking or contaminating the surrounding ocean.
  • the rigid tank and pipes may be configured such that low-density liquid naturally remains in the tank and / or minimally escapes or leaks from the rigid tank.
  • said low density liquid may be present floating above water in the second reservoir and said pipe interconnecting the water reservoir with the rigid tank may be located beneath the low density liquid - water liquid-liquid interface.
  • Reservoirs may comprise multiple interconnected reservoirs or tanks or storage vessels or multiple interconnected process elements or a combination thereof.
  • the an underwater storage reservoir may comprise multiple interconnected underwater tanks.
  • the third reservoir may enable the same hydrostatic pressure as ocean water, while possessing properties which are less corrosive or less prone to biofouling than ocean water.
  • the third reservoir may comprise ocean water treated with an oxygen scavenger to remove dissolved oxygen and / or prevent corrosion.
  • the third reservoir may comprise ocean water treated with a biocide or a non-corrosive or non oxidizing biocide.
  • the third reservoir may comprise an aqueous solution with the same or similar density as ocean water, except comprising a different mixture or compositions of salts and / or other reagents than ocean water which may be less corrosive or possess other advantageous properties compared to ocean water.
  • the third reservoir may comprise an aqueous solution with the same or similar density as ocean water, except comprising reagents which inhibit the formation of low density liquid - water hydrates
  • the third reservoir may comprise deep sea ocean water, which may comprise low dissolved oxygen concentrations and may be less corrosive compared to surface ocean water.
  • Separator or Flexible tank or bladder inside rigid tank may removable or replaceable. This enables the separator or Flexible tank or bladder inside rigid tank to undergo maintenance or be replaced at or near its end of life
  • Low density liquid may include, but is not limited to, one or more or a combination of the following: propane, butane, ethane, pentane, hexane, LPG, gas-liquids, oils, or other low density liquids described herein, or other liquids described in the art.
  • Ocean water temperature is generally between -2°C and 40°C.
  • Deep ocean water is generally about 4°C
  • the density of the Low Density Liquid is less than water at least in the temperature range of greater than 3°C and / or less than 40°C.
  • a condensable gas in the headspace may ensure the pressure inside the third reservoir is close to the hydrostatic pressure of the ocean at the same underwater depth, which may be beneficial if, for example, said the third reservoir is a rigid tank.
  • the vapor pressure of the condensable headspace gas may be tuned or engineered to ensure it matches or is close to hydrostatic pressure of the ocean at the same underwater depth at the expected operating temperature.
  • the expected operating temperature may range from, for example, -2°C to 50°C, depending on the water body, the depth, the time of year, the surface temperature, the local climate, the water temperature surrounding or in contact with one or more components of the system, other conditions, or a combination thereof.
  • the pipe connection between an underwater tank and a pipe may be designed to be capable of safe disconnection or re-connection or both.
  • An underwater tank may be disconnected from a pipe for maintenance or replacement or expansion or monitoring of the underwater tank, underwater pipe, other underwater component, or a combination thereof.
  • an underwater tank or pipe or both may contain low density liquid during disconnection.
  • An underwater tank may be disconnected from a pipe for maintenance or replacement.
  • an underwater tank or pipe or both may contain low density liquid during disconnection.
  • low density liquid may be removed from an underwater tank before disconnecting said underwater tank.
  • Safe disconnection may involve minimal or no leaks of low density liquid.
  • Some embodiments of the present invention may be designed to enable replacement or maintenance of an underwater tank.
  • Some embodiments of the present invention may be designed to enable the transfer of an underwater tank to the surface and / or return of said underwater tank to its original location. Some embodiments of the present invention may enable one or more components or subcomponents of an underwater tank or other underwater components to be removed, or replaced, or maintained if desirable. Some embodiments of the present invention may enable the addition of one or more tanks underwater while integrating with pre-existing underwater infrastructure and / or surface infrastructure. For example, a Separator or Flexible tank or bladder inside a rigid tank may be removable or replaceable.
  • Removability or replaceability may involve the ability to remove or replace a component while maintaining operations or with minimal disruption to operations.
  • projects may initially employ depths less than or equal to a 3,000 meter ocean water depth. As pipelaying techniques and subsea services advance, depths greater than a 3,000 meter ocean water depth may be employed.
  • a dilute concentration of propane may exist in the water due to the high pressures under the water enabling some propane solubility. Because the present embodiment is closed / not open to air, the propane cannot be released into the air.
  • the headspace may be occupied by a hydrocarbon refrigerant which boils at around room temperature.
  • a hydrocarbon refrigerant which boils at around room temperature.
  • refrigerant compresses and condensed into a liquid (significantly reducing the amount of compression required).
  • the condensed refrigerant forms a floating layer on the water.
  • the refrigerant boils on the surface of the water.
  • propane or butane gas may be removed from the tank headspace to enable the water to occupy the space without compressing the propane.
  • the propane gas may be removed via compression into a separate tank.
  • the present invention may store electricity by displacing water with a low- density liquid (LDL). Electricity may be stored in the form of gravitational potential energy from the gravitational hydrostatic pressure difference between the LDL and water.
  • LDL low- density liquid
  • the surface valve (5) is opened. Water inside the surface water tank (6) travels through the water pipe (7) and naturally displaces LDL inside the underwater rigid tank (2). Displaced LDL travels through the LDL pipe (3) and into the generator (4) at the surface, generating electricity, and flowing LDL into the rigid LDL surface tank. When charging is complete, the surface valve (5) is closed.
  • Supplemental Thermal storage may comprise a process or system for storing or recovering or both thermal energy from low density liquid, high density liquid, or a combination thereof.
  • Thermal energy recovered may comprise, for example, thermal energy retained in the ‘cold’ temperature of refrigerated or cooled low density liquid.
  • Supplemental thermal storage may be required to enable an efficient operation in a system with various system components operating at different temperatures.
  • Supplemental thermal storage may be required to enable an efficient operation in a system with a cooled or refrigerated higher elevation low density liquid reservoir which may operate at temperatures lower than surface ocean water or ground or air or combination thereof temperatures.
  • Parasitic Energy Energy consumption which reduces system performance or efficiency or both.
  • Non-Parasitic Energy Energy consumption which has a negligible impact or no impact or positive impact or a combination thereof on system performance or efficiency or both.
  • Reservoir or tank may comprise an equipment or a device for storing material, such as low density liquid or higher density liquid or both. Reservoir or tank may be used interchangeably. It is important to note that in some instances, reservoir may be used broadly to describe the general storage of a fluid or fluids in a region, or zone, or depth, or a range, or a combination thereof. It is important to note that in some instances, tank may be used broadly to describe the general storage of a fluid or fluids in a region, or zone, or depth, or a range, or a combination thereof.
  • tank may be used narrowly to describe an individual storage unit for the storage of a fluid or fluids in a region, or zone, or depth, or a range, or a combination thereof.
  • reservoir may be used narrowly to describe an individual storage unit for the storage of a fluid or fluids in a region, or zone, or depth, or a range, or a combination thereof.
  • Low Density Liquid or Lower Density Liquid or LDL A working fluid which has a lower density than a high density liquid.
  • High Density Liquid or Higher Density Liquid or HDL or Greater Density Liquid A working fluid which has a higher density than a low density liquid.
  • Cooling or ‘Refrigerate’ Removing heat from liquid or system or both. Removing heat using, for example, heat transfer, heat exchange, refrigeration cycle, radiant cooling, or other heat removal, or a combination thereof.
  • a reservoir or working fluid or both which is cooled to a temperature less than at least some ambient temperature.
  • a reservoir or working fluid or both which is cooled to a temperature less than at least some ambient temperature, although the working fluid may require a pressure greater than atmospheric pressure to be stored at a liquid phase.
  • Working Lluid A liquid or gas or both which is employed in the system to store potential energy or heat or both.
  • Thermal Storage Medium or Thermal Storage Media or Thermal Storage Liquid A material which stores, or transfers, or a combination thereof heat.
  • ‘Cold’ Thermal Storage Medium or ‘Cold’ Thermal Storage Media Material which is at a temperature colder than ‘Warm’ Thermal Storage Medium or ‘Warm’ Thermal Storage Media.
  • ‘Cold’ Thermal Storage Medium or ‘Cold’ Thermal Storage Media may be at or near the temperature of refrigerated or cooled low density liquid or near or at the temperature of low density liquid in a cooled or refrigerated or semi-refrigerated higher elevation low density liquid reservoir.
  • ‘Cold’ Thermal Storage Medium or ‘Cold’ Thermal Storage Media may be at a temperature of refrigerated or cooled low density liquid plus or minus the heat exchanger losses and other potential losses.
  • ‘Warm’ Thermal Storage Medium or ‘Warm’ Thermal Storage Media Material which is at a temperature warmer than ‘Cold’ Thermal Storage Medium or ‘Cold’ Thermal Storage Media. ‘Warm’ Thermal Storage Medium or ‘Warm’ Thermal Storage Media may be at a temperature above the temperature of refrigerated or cooled low density liquid or above the temperature of low density liquid in a cooled or refrigerated or semi-refrigerated higher elevation low density liquid reservoir.
  • ‘Cold’ A temperature of a medium which is a temperature less than the same medium at a ‘warm’ temperature.
  • ‘cold’ may be a temperature less than an ambient air temperature or an ambient water temperature or an ambient ground temperature or a combination thereof.
  • ‘cold’ may be a temperature near or at or less than the temperature or temperature range of a cooled or refrigerated or semi- refrigerated low density liquid reservoir.
  • ‘Warm’ A temperature of a medium which is a temperature greater than the same medium at a ‘warm’ temperature.
  • ‘warm’ may be a temperature greater than an ambient air temperature or an ambient water temperature or an ambient ground temperature or a combination thereof.
  • ‘warm’ may be a temperature near or at or greater than the temperature or temperature range of a cooled or refrigerated or semi-refrigerated low density liquid reservoir.
  • ‘Cold’ Low Density Liquid Low density liquid at a temperature less than ‘warm’ low density liquid.
  • ‘cold’ low density liquid may be a temperature of a low density liquid where the low density liquid possesses a vapor pressure near or equal to or less than the pressure limit or pressure rating of a cooled or refrigerated or semi- refrigerated higher elevation low density liquid reservoir
  • ‘Warm’ Low Density Liquid Low density liquid at a temperature greater than ‘cold’ low density liquid.
  • ‘warm’ low density liquid may be a temperature of a low density liquid where the low density liquid possesses a vapor pressure near or equal to or greater than the pressure limit or pressure rating of a cooled or refrigerated or semi-refrigerated higher elevation low density liquid reservoir
  • Thermal Management A process for removing, adding, or otherwise transferring heat. A process which may monitor and / or adjust the temperature of one or more or a combination of fluids or components and may, automatically or with oversight or both, make adjustments or add or remove heat or a combination thereof.
  • a low boiling point liquid may comprises a liquid with a vapor pressure about equal to or greater than 1 atm at a temperature less than 60 degrees Celsius, or 50 degrees Celsius, or 40 degrees Celsius, or a combination thereof.
  • a low boiling point liquid may comprises a liquid with a vapor pressure about equal to or greater than 1 atm at a temperature less than 100 degrees Celsius, or 90 degrees Celsius, or 80 degrees Celsius, or 70 degrees Celsius, or 60 degrees Celsius, or 50 degrees Celsius, or 40 degrees Celsius, or 30 degrees Celsius or a combination thereof.
  • Enhanced Density Higher Density Liquid In some embodiments, a liquid with a density greater than water or ocean water or the water of a water body or a combination thereof. In some embodiments, a solution comprising a solvent and reagents with a density greater than said solvent.
  • Solubility A reagent or liquid or a combination thereof which possesses a solubility less than 99%, or 90%, or 80%, or 70%, or 60%, or 50%, or 40%, or 30%, or 20%, or 10%, or 5%, or 1% or a combination thereof in another reagent or liquid.
  • Parasitic Load The energy or material or a combination thereof demand from processes which reduce the performance or efficiency of a system, although may be required or helpful or desired for said system’s operation.
  • Ocean May comprise ocean, or a body of water, or a lake, or a body of liquid comprising a high density liquid, or a combination thereof.
  • Figure 88 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a cold supplemental thermal storage reservoir, a warm supplemental thermal storage reservoir, a heat exchanger, a pump and / or generator, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment storing energy, such as electricity, which may also be referred to as undergoing a state of charging.
  • Figure 89 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a cold supplemental thermal storage reservoir, a warm supplemental thermal storage reservoir, a heat exchanger, a generator and / or pump, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment generating energy, such as electricity, which may also be referred to as undergoing a state of discharging.
  • Figure 90 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a higher elevation high density liquid reservoir, a cold supplemental thermal storage reservoir, a warm supplemental thermal storage reservoir, a heat exchanger, a generator and / or pump, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment storing energy, such as electricity, which may also be referred to as undergoing a state of charging.
  • Figure 91 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a higher elevation high density liquid reservoir, a cold supplemental thermal storage reservoir, a warm supplemental thermal storage reservoir, a heat exchanger, a pump and / or generator, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment generating energy, such as electricity, which may also be referred to as undergoing a state of discharging.
  • Figure 92 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a supplemental thermal storage reservoir which may possess temperature layers or a temperature gradient, a heat exchanger, a pump and / or generator, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment storing energy, such as electricity, which may also be referred to as undergoing a state of charging.
  • Figure 93 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a supplemental thermal storage reservoir which may possess temperature layers or a temperature gradient, a heat exchanger, a generator and / or pump, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment generating energy, such as electricity, which may also be referred to as undergoing a state of discharging.
  • Figure 94 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a higher elevation high density liquid reservoir, a supplemental thermal storage reservoir which may possess temperature layers or a temperature gradient, a heat exchanger, a pump and / or generator, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment storing energy, such as electricity, which may also be referred to as undergoing a state of charging.
  • Figure 95 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a higher elevation high density liquid reservoir, a supplemental thermal storage reservoir which may possess temperature layers or a temperature gradient, a heat exchanger, a generator and / or pump, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment generating energy, such as electricity, which may also be referred to as undergoing a state of discharging.
  • Figure 96 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a heat exchanger, a pump and / or generator, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment storing energy, such as electricity, which may also be referred to as undergoing a state of charging.
  • Figure 97 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a heat exchanger, a generator and / or pump, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment generating energy, such as electricity, which may also be referred to as undergoing a state of discharging.
  • Figure 98 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a higher elevation high density liquid reservoir, a supplemental thermal storage reservoir which may possess temperature layers or a temperature gradient, a heat exchanger, a generator and / or pump, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment generating energy, such as electricity, which may also be referred to as undergoing a state of discharging.
  • Figure 99 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present embodiment may comprise, including, but not limited to, one or more or a combination of the following: a higher elevation low density liquid reservoir, a cooling system for cooling said higher elevation low density liquid reservoir, a heat exchanger, a pump and / or generator, a lower elevation reservoir, and interconnecting pipes.
  • the present figure may show the present embodiment storing energy, such as electricity, which may also be referred to as undergoing a state of charging.
  • Figure 100 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation reservoir low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located on land and the lower elevation reservoir may be located under water.
  • Figure 101 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located on land and the lower elevation reservoir may be located underwater.
  • Figure 102 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located underwater near or on the seabed and the lower elevation reservoir may be located under water near or on the seabed.
  • Figure 103 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located underwater near or on the seabed and the lower elevation reservoir may be located under water near or on the seabed.
  • Figure 104 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located in the water as a semi-submersible or fully submersed or combination thereof vessel and the lower elevation reservoir may be located under water near or on the seabed.
  • Figure 105 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located in the water as a semi-submersible or fully submersed or combination thereof vessel and the lower elevation reservoir may be located under water near or on the seabed.
  • Figure 106 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located in the water as a floating vessel and the lower elevation reservoir may be located under water near or on the seabed.
  • Figure 107 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a higher elevation low density liquid reservoir and a lower elevation reservoir, wherein the higher elevation reservoir may be located in the water as a floating vessel and the lower elevation reservoir may be located underwater near or on the seabed.
  • Figure 108 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or above and / or on the seabed.
  • Figure 109 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or above and / or on the seabed.
  • Figure 110 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or above and / or on the seabed.
  • Figure 111 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or above and / or on the seabed.
  • Figure 112 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or underground beneath the seabed or buried or a combination thereof.
  • Figure 113 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or underground beneath the seabed or buried or a combination thereof.
  • Figure 114 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or underground beneath the seabed or buried or a combination thereof.
  • Figure 115 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underwater and / or underground beneath the seabed or buried or a combination thereof.
  • Figure 116 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underground.
  • Figure 117 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underground.
  • Figure 118 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underground.
  • Figure 119 A process for energy storage which stores electricity by displacing a higher density liquid with a lower density liquid.
  • the present figure may show an embodiment with a lower elevation reservoir underground.
  • Figure 94 and Figure 95 [0495] Figure 96 and Figure 97:
  • Figure 98 and Figure 99 Example Step-by-Step Descriptions of Figures [0497]
  • Figure 88 Example Step-by-Step Descriptions of Figures [0497]
  • Figure 88 Example Step-by-Step Descriptions of Figures [0497]
  • Figure 88 Example Step-by-Step Descriptions of Figures [0497]
  • Figure 88 Example Step-by-Step Descriptions of Figures [0497]
  • Figure 88 Example Step-by-Step Descriptions of Figures
  • ‘Cold’ low density liquid may be transferred from a refrigerated or cooled higher elevation low density liquid reservoir to a heat exchanger.
  • Said heat exchanger may involve heat exchanging ‘cold’ low density liquid with ‘warm’ thermal storage medium, forming ‘warm’ low density liquid and ‘cold’ thermal storage medium.
  • ‘Cold’ thermal storage medium may be stored in a ‘cold’ thermal storage reservoir.
  • ‘Warm’ low density liquid is transferred to ‘2)’.
  • ‘Warm’ low density liquid is pumped using one or more pumps to a lower elevation reservoir, where low density liquid displaces high density liquid.
  • Said pump may be powered by energy, such as electricity, and said energy may be stored during said displacing of a high density liquid with a low density liquid.
  • Low density liquid in a lower elevation reservoir may be allowed to be displaced by high density liquid. Displaced low density liquid may be transferred in a pipe to a generator, generating electricity. Upon reaching higher elevation parts, which may include said generator, low density liquid may be ‘warm’, which may mean the low density liquid is at a higher temperature than low density liquid in a cooled or refrigerated higher elevation reservoir.
  • ‘Warm’ low density liquid may enter a heat exchanger.
  • Said heat exchanger may involve heat exchanging ‘warm’ low density liquid with ‘cold’ thermal storage medium, forming ‘cold’ low density liquid and ‘warm’ thermal storage medium.
  • ‘Warm’ thermal storage medium may be stored in a ‘warm’ thermal storage reservoir.
  • ‘Cold’ low density liquid may be transferred to a refrigerated or cooled higher elevation low density liquid reservoir.
  • ‘Cold’ low density liquid may be transferred from a refrigerated or cooled higher elevation low density liquid reservoir to a heat exchanger.
  • Said heat exchanger may involve heat exchanging ‘cold’ low density liquid with ‘warm’ thermal storage medium, forming ‘warm’ low density liquid and ‘cold’ thermal storage medium.
  • ‘Cold’ thermal storage medium may be stored in a ‘cold’ thermal storage reservoir.
  • ‘Warm’ low density liquid is transferred to ‘2)’.
  • ‘Warm’ low density liquid is pumped using one or more pumps to a lower elevation reservoir, where low density liquid displaces high density liquid.
  • Said pump may be powered by energy, such as electricity, and said energy may be stored during said displacing of a high density liquid with a low density liquid. Displaced high density liquid may be transferred through a pipe to a higher elevation high density liquid reservoir.
  • Low density liquid in a lower elevation reservoir may be allowed to be displaced by high density liquid in a higher elevation reservoir.
  • High density liquid from a higher elevation reservoir is transferred in a pipe to a lower elevation reservoir, displacing low density liquid in said lower elevation reservoir.
  • Said displaced low density liquid may be transferred in a pipe to a generator, generating electricity.
  • low density liquid may be ‘warm’, which may mean the low density liquid is at a higher temperature than low density liquid in a cooled or refrigerated higher elevation reservoir.
  • ‘Warm’ low density liquid may enter a heat exchanger.
  • Said heat exchanger may involve heat exchanging ‘warm’ low density liquid with ‘cold’ thermal storage medium, forming ‘cold’ low density liquid and ‘warm’ thermal storage medium.
  • ‘Warm’ thermal storage medium may be stored in a ‘warm’ thermal storage reservoir.
  • ‘Cold’ low density liquid may be transferred to a refrigerated or cooled higher elevation low density liquid reservoir.
  • ‘Cold’ low density liquid may be transferred from a refrigerated or cooled higher elevation low density liquid reservoir to a heat exchanger.
  • Said heat exchanger may involve heat exchanging ‘cold’ low density liquid with ‘warm’ thermal storage medium, forming ‘warm’ low density liquid and ‘cold’ thermal storage medium.
  • ‘Cold’ thermal storage medium may be stored in a thermal storage reservoir.
  • ‘Warm’ low density liquid may be transferred to ‘2)’.
  • ‘Warm’ low density liquid may be pumped using one or more pumps to a lower elevation reservoir, where low density liquid displaces high density liquid.
  • Said pump may be powered by energy, such as electricity, and said energy may be stored during said displacing of a high density liquid with a low density liquid.
  • Low density liquid in a lower elevation reservoir may be allowed to be displaced by high density liquid. Displaced low density liquid may be transferred in a pipe to a generator, generating electricity. Upon reaching higher elevation parts, which may include said generator, low density liquid may be ‘warm’, which may mean the low density liquid is at a higher temperature than low density liquid in a cooled or refrigerated higher elevation reservoir.
  • ‘Warm’ low density liquid may enter a heat exchanger. Said heat exchanger may involve heat exchanging ‘warm’ low density liquid with ‘cold’ thermal storage medium, forming ‘cold’ low density liquid and ‘warm’ thermal storage medium. ‘Warm’ thermal storage medium may be stored in a thermal storage reservoir. ‘Cold’ low density liquid may be transferred to a refrigerated or cooled higher elevation low density liquid reservoir.
  • ‘Cold’ low density liquid may be transferred from a refrigerated or cooled higher elevation low density liquid reservoir to a heat exchanger.
  • Said heat exchanger may involve heat exchanging ‘cold’ low density liquid with ‘warm’ thermal storage medium, forming ‘warm’ low density liquid and ‘cold’ thermal storage medium.
  • ‘Cold’ thermal storage medium may be stored in a thermal storage reservoir.
  • ‘Warm’ low density liquid is transferred to ‘2)’.
  • ‘Warm’ low density liquid is pumped using one or more pumps to a lower elevation reservoir, where low density liquid displaces high density liquid.
  • Said pump may be powered by energy, such as electricity, and said energy may be stored during said displacing of a high density liquid with a low density liquid. Displaced high density liquid may be transferred through a pipe to a higher elevation high density liquid reservoir.
  • Low density liquid in a lower elevation reservoir may be allowed to be displaced by high density liquid in a higher elevation reservoir.
  • High density liquid from a higher elevation reservoir is transferred in a pipe to a lower elevation reservoir, displacing low density liquid in said lower elevation reservoir.
  • Said displaced low density liquid may be transferred in a pipe to a generator, generating electricity.
  • low density liquid may be ‘warm’, which may mean the low density liquid is at a higher temperature than low density liquid in a cooled or refrigerated higher elevation reservoir.
  • ‘Warm’ low density liquid may enter a heat exchanger. Said heat exchanger may involve heat exchanging ‘warm’ low density liquid with ‘cold’ thermal storage medium, forming ‘cold’ low density liquid and ‘warm’ thermal storage medium. ‘Warm’ thermal storage medium may be stored in a thermal storage reservoir. ‘Cold’ low density liquid may be transferred to a refrigerated or cooled higher elevation low density liquid reservoir. [0505] Figure 96:
  • ‘Cold’ low density liquid is pumped using one or more pumps to a lower elevation reservoir, where low density liquid displaces high density liquid.
  • Said pump may be powered by energy, such as electricity, and said energy may be stored during said displacing of a high density liquid with a low density liquid.
  • Low density liquid in a lower elevation reservoir may be allowed to be displaced by high density liquid. Said displaced low density liquid may be transferred in a pipe to a generator, generating electricity. Upon reaching higher elevation parts, which may include said generator, low density liquid may be ‘warm’, which may mean the low density liquid is at a higher temperature than low density liquid in a cooled or refrigerated higher elevation reservoir. Said ‘warm’ low density liquid may undergo cooling before, during, or after or a combination thereof entering a cooled or refrigerated low density liquid higher elevation reservoir.
  • ‘Cold’ low density liquid is pumped using one or more pumps to a lower elevation reservoir, where low density liquid displaces high density liquid.
  • Said displaced high density liquid may be transferred in a pipe to a higher elevation high density liquid reservoir.
  • Said pump may be powered by energy, such as electricity, and said energy may be stored during said displacing of a high density liquid with a low density liquid.
  • Low density liquid in a lower elevation reservoir may be allowed to be displaced by high density liquid in a higher elevation reservoir.
  • High density liquid from a higher elevation reservoir is transferred in a pipe to a lower elevation reservoir, displacing low density liquid in said lower elevation reservoir.
  • Said displaced low density liquid may be transferred in a pipe to a generator, generating electricity.
  • low density liquid may be ‘warm’, which may mean the low density liquid is at a higher temperature than low density liquid in a cooled or refrigerated higher elevation reservoir.
  • Said ‘warm’ low density liquid may undergo cooling before, during, or after or a combination thereof entering a cooled or refrigerated low density liquid higher elevation reservoir.
  • the low density liquid may possess a low boiling point.
  • the external pressure or ambient pressure surrounding a low density liquid reservoir may be less than the vapor pressure of the low density liquid if the low density liquid is stored at ambient temperature. If the pressure of the low density liquid inside a reservoir exceeds the pressure surrounding or adjacent to said reservoir, the reservoir may be ‘pressurized’ and must be resistant to said pressure to ensure safety and prevent rupture.
  • Pressurized reservoirs such as ASME pressurized tanks, are utilized for storing butane, propane, LPG, and other volatile liquid storage in the art and may be employed.
  • pressurized tanks may require thicker walls, or stronger reinforcement, or stronger materials, or a combination thereof compared to non-pressurized tanks.
  • pressurized tanks are generally more expensive than non-pressurized tanks for storing the same mass of volatile liquid.
  • the higher the pressure rating or pressure resistance generally the more expensive the tank.
  • one or more low density liquid reservoirs may be cooled or actively cooled or undergo some form of thermal management.
  • a higher elevation low density liquid reservoir may be cooled or refrigerated. Cooling or ‘refrigerate’ may be employed interchangeably, and may simply describe the active removing of heat.
  • a higher elevation low density liquid storage reservoir may be cooled or refrigerated to reduce the required pressure resistance of a higher elevation low density liquid storage reservoir or enable a higher elevation low density liquid storage reservoir to be non-pressurized or a combination thereof.
  • Refrigerated storage tanks are utilized for storing butane, propane, LPG, and other volatile liquids in the art and may be employed.
  • Active refrigerating or cooling may require energy input and said energy input may be parasitic.
  • the energy required to refrigerate or cool low density liquid may decrease total round trip energy efficiency.
  • Minimizing energy required in refrigerating or cooling a low density liquid storage reservoir may be advantageous to maximizing round trip energy efficiency of the energy storage system.
  • a higher elevation low density liquid storage reservoir may be refrigerated.
  • a refrigerated or cooled storage reservoir may enable lower capital cost due to, for example, the capability of using a non-pressurized tank or less pressurized tank.
  • a refrigerated higher elevation low density liquid storage reservoir may be employed with the integration of supplemental thermal storage.
  • Supplemental thermal storage may be employed to minimize parasitic energy requirements associated with refrigerating or cooling a low density liquid storage reservoir.
  • Supplemental thermal storage may be employed to minimize the required cooling or refrigeration capacity, or ‘cooling tonnage’, to refrigerate or cool a low density liquid storage reservoir, which may minimize the capital cost or energy demands or a combination thereof of the cooling equipment.
  • Supplemental thermal storage may be integrated to recover the ‘cold’ stored in a low density liquid’s specific heat capacity before a low density liquid is transferred to a lower elevation reservoir during the storing of electricity or ‘charging’ of the energy storage system.
  • Supplemental thermal storage may be integrated to cool a low density liquid before transferring said low density liquid into a refrigerated or cooled higher elevation low density liquid storage reservoir during the generation of electricity or ‘discharging’ of the energy storage system.
  • an integrated supplemental thermal storage system may involve a thermal storage reservoir, a thermal storage media, a heat transfer media, and a heat exchanger.
  • the thermal storage media and the heat transfer media may comprise the same media and may comprise a high heat capacity liquid, which may include, but is not limited to, water, or water with a freezing point depressant, or aqueous salt brine, or aqueous brine, or a liquid-liquid phase transition liquid.
  • the thermal storage reservoir may comprise one or more storage tanks which store thermal storage media.
  • the thermal storage reservoir may comprise one tank with a temperature gradient or thermocline.
  • the thermal storage reservoir may comprise two tanks, wherein one tank may be for ‘cold’ thermal storage media and one tank may be for ‘warm’ thermal storage media.
  • the present example may a thermal storage reservoir comprising two tanks, one tank for ‘cold’ thermal storage media and one tank for ‘warm’ thermal storage media.
  • the heat exchanger may comprise a heat exchanger which facilitates heat transfer between the thermal storage media and the low density liquid.
  • the present example may employ normal butane as a low density liquid, although other low density liquids may be employed if desired.
  • the present example may store electricity or energy by pumping a low density liquid from a higher elevation reservoir to a lower elevation reservoir, displacing water in the lower elevation reservoir.
  • the present example may generate electricity or energy by allowing water to displace low density liquid in a lower elevation reservoir, displacing the low density liquid into a pipe to a generator, generating electricity or energy, and into a higher elevation reservoir.
  • low density liquid exiting or after exiting a refrigerated higher elevation storage reservoir may pass through a heat exchanger, where the ‘cold’ low density liquid may be heat exchanged with ‘warm’ thermal storage liquid, which may result in the formation of ‘warm’ low density liquid and ‘cold’ thermal storage liquid.
  • the cold thermal storage liquid may be transferred to a thermal storage reservoir.
  • ‘Warm’ low density liquid may be transferred in a pipe to a lower elevation reservoir. Said heat exchanging may be conducted before, during, or after a pumping step.
  • the present example may involve a first pump which increases the pressure of the ‘cold’ low density liquid to a pressure greater than the vapor pressure of the low density liquid at the ‘warm’ temperature range, then, after heat exchanging in the heat exchanger, the resulting ‘warm’ low density liquid may undergo a subsequent pumping step which increases the pressure of the low density liquid to a pressure sufficient to transfer the low density liquid to a lower elevation reservoir.
  • the present example may involve pumping the ‘cold’ low density liquid to a pressure sufficient to transfer the low density liquid to the lower elevation reservoir, then heat exchanging said ‘cold’ low density liquid with ‘warm’ heat transfer liquid, and transferring the resulting ‘warm’ low density liquid to a lower elevation reservoir.
  • the heat exchanging may occur before or during the transferring of the low density liquid to a lower elevation reservoir.
  • the heat exchanger may comprise, including, but not limited to, one or more or a combination of the following: a shell in tube heat exchanger, or a plate heat exchange, or a coil wrapped around a low density liquid pipe, a thermally conductive low density liquid pipe segment, or one or more heat exchanging methods known in the art.
  • low density liquid before, during, or after, or a combination thereof entering a generator may pass through a heat exchanger, where the ‘warm’ low density liquid may be heat exchanged with ‘cold’ thermal storage liquid, which may result in the formation of ‘cold’ low density liquid and ‘warm’ thermal storage liquid.
  • the warm thermal storage liquid may be transferred to a thermal storage reservoir.
  • ‘Cold’ low density liquid may be transferred to a higher elevation reservoir, which comprise a cooled or refrigerated higher elevation reservoir.
  • said ‘cold’ low density liquid resulting from said heat exchange may be at a temperature near, or equal to, or less than the temperature of a refrigerated or cooled higher elevation low density liquid reservoir.
  • the present example may involve generating electricity from the high pressure warm low density liquid, which may depressurize the ‘warm’ low density liquid to a pressure greater than the vapor pressure of the low density liquid at the ‘warm’ temperature, then, after heat exchanging in the heat exchanger, the resulting ‘cold’ low density liquid may enter a second generator or depressurization step which may decrease the pressure of the ‘cold’ low density liquid to a pressure appropriate from transfer into a cooled or refrigerated low density liquid storage reservoir.
  • the present example may involve generating electricity from the high pressure warm low density liquid, then heat exchanging the warm low density liquid to form cold low density liquid, then transferring the cold low density liquid into a higher elevation low density liquid storage reservoir.
  • the warm low density liquid entering the heat exchanger may be at a pressure greater than or equal to the vapor pressure of the low density liquid at the ‘warm’ temperature and the ‘cold’ low density liquid exiting the heat exchanger may be at a pressure sufficient for transfer into a cooled or refrigerated higher elevation low density liquid reservoir. In some embodiments, the warm low density liquid entering the heat exchanger may be at a pressure greater than or equal to the vapor pressure of the low density liquid at the ‘warm’ temperature and the ‘cold’ low density liquid exiting the heat exchanger may require further depressurization before transfer into a cooled or refrigerated higher elevation low density liquid reservoir.
  • the warm low density liquid entering the heat exchanger may be at a pressure greater than or equal to the vapor pressure of the low density liquid at the ‘warm’ temperature and the ‘cold’ low density liquid exiting the heat exchangers may require further depressurization before transfer into a cooled or refrigerated higher elevation low density liquid reservoir.
  • the heat exchanger may comprise, including, but not limited to, one or more or a combination of the following: a shell in tube heat exchanger, or a plate heat exchange, or a coil wrapped around a low density liquid pipe, a thermally conductive low density liquid pipe segment, or one or more heat exchanging methods known in the art.
  • the pump and generator may comprise the same unit, such as a reversible pump/generator or hydraulic power recovery turbine.
  • the same heat exchanger may be employed during changing as is employed during discharging.
  • supplemental thermal storage may be beneficial to maximizing system round trip efficiency.
  • the calculations for an example system are shown below:
  • liquid normal butane may be provided as an example low density liquid.
  • the example outside ambient temperature is 30 degrees Celsius.
  • the present example comprises 1 GWh of energy storage
  • Liquid normal butane has a boiling point of about -1°C at atmospheric pressure
  • the liquid butane in the present example may be stored in a refrigerated higher elevation reservoir at about -3°C when at a stable state or emptying, and -1°C when the higher elevation reservoir is filling.
  • the present example stores electricity (charging) by pumping a low density liquid from a higher elevation reservoir to a lower elevation reservoir, displacing water in the lower elevation reservoir.
  • the present example generates electricity (discharging) by allowing water to displace a low density liquid in lower elevation reservoir, and the displaced low density liquid is transferred in a pipe to a generator, generating electricity, and into a higher elevation reservoir.
  • the temperature of the low density entering at least one higher elevation part of the system may include, but are not limited to, higher elevation pipe segments, the generator, tanks, reservoirs, and / or any heat exchangers) during discharging may be at the ambient temperature, which for the present example is 30 degrees Celsius.
  • the temperature of the low density liquid entering at least one higher elevation part of the system during discharging may be lower than ambient temperature due to the lower temperature of the deep ocean (generally about 0 to 5°C) and the generally colder temperature of the ocean (the temperature of the ocean in most of the world, including at surface water depths, is generally less than 30°C most of the year).
  • the present example shows a full charge/discharge cycle, where the higher elevation reservoir is practically emptied during charging and practically filled during discharging.
  • an energy storage system may operate at various charge and discharge states, an may undergo charging or discharging or a combination thereof when a higher elevation reservoir is partially filled or empty or full or a combination thereof.
  • the ‘warm’ thermal storage liquid is assumed to be at the example ambient temperature, or 30 degrees Celsius. In practice, the ‘warm’ thermal storage liquid may be at a temperature less than ambient due to, for example, including, but not limited to, the returning low density liquid during discharging being at a temperature less than ambient, or due to thermal management systems, or due to a combination thereof.
  • an example embodiment with a refrigerated or cooled higher elevation low density liquid reservoir with supplemental thermal storage may require significantly less cooling energy or parasitic cooling than an example embodiment with a refrigerated or cooled higher elevation low density liquid reservoir without supplemental thermal storage.
  • an example embodiment with a refrigerated or cooled higher elevation low density liquid reservoir without supplemental thermal storage may require a parasitic load or reduction in round trip efficiency of about 14 - 28% for cooling.
  • an example embodiment with a refrigerated or cooled higher elevation low density liquid reservoir with supplemental thermal storage may require a parasitic load or reduction in round trip efficiency of about 1 - 3% for cooling.
  • a supplemental thermal storage system can be advantageous to maximize the round trip efficiency of embodiments employing a refrigerated higher elevation low density liquid reservoir. Additionally, a supplemental thermal storage system can be advantageous to minimizing CAPEX, due to the smaller cooling capacity requirements in embodiments employing a refrigerated higher elevation low density liquid reservoir with supplemental thermal storage compared to embodiments employing a refrigerated higher elevation low density liquid reservoir without supplemental thermal storage.
  • normal liquid butane it may be desirable for the normal liquid butane to be cooled to a design storage temperature or design emptying temperature.
  • normal liquid butane in a refrigerated or cooled higher elevation low density liquid storage reservoir may be cooled from a temperature of -1°C to a temperature of -3°C. Said cooling may occurring during filling or during storage or during emptying or a combination thereof.
  • cooling will require 102,241 MJ of electricity or 28.4 MWh of electricity.
  • the present example energy storage system stores 1 GWh of electricity, so 28.4 MWh of electricity is a cooling parasitic load of 2.84% or reduces the overall round trip efficiency of the energy storage system by about 2.84%.
  • a cold thermal storage may be cooled to a design temperature lower than or equal to the design low density liquid storage temperature before, during, or after or a combination thereof heat exchange with ‘cold’ low density liquid.
  • ⁇ 2 Discharging: During discharging from 100% to 0%, 134,823 metric tons of ‘warm’ liquid normal butane enters higher elevation parts .
  • the ‘warm’ liquid normal butane is ambient temperature, which for this example is 30°C.
  • ‘warm’ low density liquid may be colder than ambient temperature or may be warmer than ambient temperature or both.
  • ‘warm’ liquid butane must be cooled from 30°C to -3°C, or at least to - 1°C, before entering a refrigerated or cooled low density liquid higher elevation reservoir.
  • ‘warm’ liquid butane must be cooled from 30°C to -3°C, or at least to -1°C. Said cooling may occurring during filling or during storage or during emptying or a combination thereof.
  • cooling will require 1,012,183 MJ of electricity or 281.2 MWh of electricity.
  • the present example energy storage system stores 1 GWh of electricity, so 281.2 MWh of electricity is a cooling parasitic load of 28.12% or reduces the overall round trip efficiency of the energy storage system by about 28.12%.
  • cooling will require 506,091 MJ of electricity or 140.58 MWh of electricity.
  • the present example energy storage system stores 1 GWh of electricity, so 140.58 MWh of electricity is a cooling parasitic load of 14.058% or reduces the overall round trip efficiency of the energy storage system by about 14.058%.
  • ‘cold’ thermal storage medium may be maintained at a temperature less than or equal to the temperature of low density liquid in a refrigerated or cooled low density liquid storage reservoir. Said maintaining may involve some form of thermal management. For example, said thermal management may involve systems and methods for cooling or temperature control or temperature monitoring or a combination thereof described herein or known in the art or a combination thereof.
  • a thermal management system employed for a ‘cold’ thermal storage medium may be overlapping or integrated with the thermal management system employed in cooling a refrigerated low density liquid storage reservoir.
  • a thermal management system employed for a ‘cold’ thermal storage medium may be separate from the thermal management system employed in cooling a refrigerated low density liquid storage reservoir.
  • Additional systems and methods for minimizing parasitic energy consumption related to cooling or refrigerating a low density liquid reservoir may include, but are not limited to:
  • the resulting low density liquid vapors may be recirculated internally by, for example, condensing said vapors into a liquid by means of compression, cooling, or both.
  • Said condensed low density liquid vapors which may comprise liquid low density liquid, may be returned to a low density liquid reservoir at a liquid phase.
  • said low density liquid vapors may be used for another application, which may include, but is not limited to, as a fuel or an industrial feedstock or a chemical feedstock or a refrigerant, or a combination thereof.

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EP4183024A4 (en) 2024-09-04
MX2023000800A (es) 2023-06-01
WO2022016034A1 (en) 2022-01-20
CA3186194A1 (en) 2022-01-20
AU2021308651A1 (en) 2023-02-16
BR112023000854A2 (pt) 2023-04-04
IL299912A (en) 2023-03-01
JP2023535158A (ja) 2023-08-16

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