GB2586336A

GB2586336A - A boost pumped hydro energy storage system

Info

Publication number: GB2586336A
Application number: GB2009397.7A
Authority: GB
Inventors: Ball Stanley
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-14
Filing date: 2020-06-19
Publication date: 2021-02-17
Anticipated expiration: 2040-06-19
Also published as: GB202009397D0; GB201911635D0; GB2586336B

Abstract

A boost pumped hydro energy storage system has boost pumps 26 located at a high water storage reservoir level 20, which take in water at the ambient reservoir pressure level and boost compress it to an increased pressure for injection into an existing conduit 27 at the water storage level, or inject it to the top of a vertically extended conduit 29. A buffer tank 24 and remote control station 25 may be installed at the top of the vertically extended conduit 29. The water pressure (head) for generation is therefore greater than is produced by the height difference alone between the upper reservoir 20 and the lower reservoir 14.

Description

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Field of Invention

The present invention relates to a hydro energy storage system and in particular a boost pumped hydro energy storage system without a requirement for the reservoir to be at an appropriate height.

Background

Global warming is a major problem caused by carbon dioxide (CO2) from fossil fuel powered power stations across the world.

Green energy systems are being built but they are all inconsistent in their generation capacity.

Pumped hydro energy storage (PHES) systems are the most efficient at 80 -90% efficiency but sites with appropriate geological locations and height are very difficult to find.

Conventional PHES systems on high mountains requires about 200m to 300m for high reservoirs to be economic.

Existing systems do not disclose boost pressure pumps at the high storage reservoir level and often rely on gravitational pressure of water. To hold sufficient water volumes all storage reservoirs are open top and therefore can only have ambient air pressure on the surface of the storage level reservoir and also in any connecting canals.

The present invention provides a means generate energy without a requirement for the reservoir to be at height.

Prior Art

US2008/253837 (MILLER) discloses a reservoir system with pumps.

US2962599 (PIRKEY) discloses a reservoir system with a penstock that drives a turbine.

Summary of Invention

The present invention relates to a boost pumped system of hydroelectric regeneration, in which boost pumps located at a high water storage reservoir level, take in water at the ambient reservoir pressure level and boost compress it to an increased pressure for injection into an existing conductor at the water storage level or inject it to the top of a vertically extended conductor.

The present invention is a modification to a conventional (PHES) pumped hydro energy storage system, design to overcome geological problems and increase its economical capacity by a boost pumped system located at the high water storage reservoir level, and where necessary an increased conductor height to increase the return flow capacity.

Conventional (PHES) pumped hydro energy storage systems have a ground level supply reservoir and a ground level reversible pump / generator which pumps water to a high level storage water level.

The water conductor determines the pressure of water which is 1.4 times the meter height of the conductor (which = 0.43PSI per foot).

The volume of water in the high water storage reservoir needs to be large and therefore the reservoir needs to be open tap and at ambient pressure of its height.

When required the water flow in the conductor is reversed down to the reversible pump / generator for electrical regeneration.

For geological and design reasons it may be necessary that an extended conductor is at a vertical angle above the storage reservoir, which may give a small reduction of the vertical conductor height and hence a small reduction in the vertical extended conductor height and pressure.

Pumped hydro generation is calculated as weight of water lifted in the conductor pipe X volume of water.

It is herein proposed that more sites can become available by the use of a boost pumped hydroelectric storage system.

In which green energy such as, solar, wind, wave, or tidal energy surplus to grid requirements or waste energy from the likes of industry or remaining power stations waste energy.

Many lower mountainous countries have low fresh water reservoirs with hydro generation, by through dam hydro generators with only a water differential pressure of part of the reservoir height say 30m such reservoirs could be converted to pump water to a higher constructed reservoir at say 100m and use booster pumps at the constructed higher reservoir, to gain the gravitational hydrostatic pressure of say 140 psi. With a vertically increased conductor-This would increase the pressure at the top of the conductor but not the volume-However the boost pump suction could take the full operational volume of 100m high storage reservoir-By boost pumping both pressure and volume could be injected into the conductor either at the 100m or 200 m level. Depending on geology location and design these calculation would be varied to suit. Some modification may also be required to accommodate the increased generation.

In well-known conventional high mountainous countries the reservoirs can have small volumetric capacities, so in the past a group of reservoirs have transferred water to the higher reservoir to increase the volumetric capacity of the highest reservoir; however the resultant pressure is the same as the original high reservoir pressure.

It is the purpose of this boost pump proposal to increase the electrical regeneration pressure above the pressure of the highest reservoir.

This boost pump system can be applied to the highest reservoir on the individual grouped reservoirs or can be considered as separate entities for modification to the boost pump system.

This proposed boost pump system can be applied without the need for water volume transfer, which is also advantageous to lower uneconomical reservoirs.

The boost pumped hydro energy storage system can also benefit the operation of desalination plants in appropriate areas.

To improve difficult and uneconomical hydro systems.

Well known are pumped hydro energy storage systems in which fresh water from a near ground level, large volume reservoir in which a near ground level reversible pump / generator pumps water up a pipe like conduit to a large volume storage reservoir on the likes of a high mountain range.

The power on the reversible pump / generator is the pressure of water in the conduit between the reversible pump / generator and the outlet to the storage reservoir times the volume of water pumped per unit of time.

At the reservoir storage the open top reservoir pressure is the ambient air pressure at that height.

However the stored water has a potential energy of its height but this potential energy of its height but this potential energy is the pressure on the surface holding the stored water up.

When required the water flow is reversed so that it has the pressure at the reversible pump! generator of the water weight in the conductor plus its potential energy.

The reversible pump! generator has near equal energy from pumping up to running back down less the electricity [mechanical / friction inefficiencies which gives it approximately 80 -90% overall efficiency.

Pump hydro energy storage need large reservoir volumes and high mountain ranges or terrain storage reservoirs, but such conditions are hard to locate Some USA geology has groups of smaller volume reservoirs, which can transfer water to a main storage reservoir to increase the water volumetric capacity, but not the pressure of the main high storage reservoir.

Such grouping only has the pressure of the main reservoir, but can be improved by boost pumping at the main high reservoir. Or each of the individual group reservoirs can be considered as separate boost pump applications.

If the highest reservoir is used to recharge the lower group reservoirs then the pressure head between the high and low level reservoirs, is the difference is the hydrostatic pressure loss.

In many countries the geology is only low level mountainous levels or terrain, and appropriate sites are difficult to identify or create, and for this reason well known conventional (PHES) pumped hydro energy storage systems are not possible and such countries revert to smaller and less economical hydroelectric generation systems.

Some with smaller reservoirs at uneconomical heights and volumes, and as such these sites can be made efficient by including boost pumped designs.

Some run on the river locations can be improved by boost pump designs.

Some through reservoir dam hydro generation can be improved by boost pump designs.

Some industrial and domestic water storage reservoirs can extract and return water to the reservoir without loss, as this can be use full at times of drought.

The power to drive a boost pump / hydro system can be grid / green energy! or self generation.

A typical example of a boost pumped hydro system will now be explained with the aid of drawings, with valves and pipes not shown,

Brief Description of Figures

Figure 1 shows a well-known conventional pumped hydro energy storage system as used in Scotland for over fifty years; Figure 2 shows a pumped hydro energy storage (PHES) system and Figure 3 shows a fresh water supply reservoir with a dam and through dam hydro generators.

Detailed Description

Figure 1 shows the ground level (1) a supply reservoir (2) a mountain (3) a high storage reservoir (4) a control station (5) the grid electrical supply (6) the green energy supply (7) The reversible pump / generators (8) the water conductor (9) the high terrain (10) with a storage reservoir (11).

Figure 2 shows a pumped hydro energy storage (PHES) system with lower terrain (13) and a lower uneconomical storage reservoir (20).

Figure 2 shows the ground level (12) a ground level supply reservoir (14) a control centre (15) with electrical yid supply (16) and the green energy electrical supply (17) a reversible pump / generator (18) a pumped water conductor (19) and with a supply pipe (21) to the uneconomical storage reservoir (20) a vertical extended conductor (22) with a tunnel (23) a buffer tank (24) a remote control station (25) a boost pump (26) drawing water from the storage reservoir (20) and pumping by pipe connection (27) to the riser pipe (28) insulated to stop the boost water from freezing (29) and a coupling for the extended conductor (30).

Figure 3 shows an existing supply reservoir (31) has a through dam hydro system (32) with through dam generators (33) which flows down a spill way to the river (34) Through dam generators only have poor generation with only a maximum of thirty meters of head pressure and the oufflow water is lost to a lower river.

It is therefore proposed that the through dam hydro system be supplemented with a pumped hydro system as described.

A reversible pump / generator (35) pumps water up a conductor (36) to an existing or constructed uneconomical median height storage reservoir (37) on low terrain (38) a boost pump (39) pumps the boosted water up a vertically extended conductor (40) leading to a buffer tank (41) and remote operational and central data centre (42) in the tunnel (43).

The higher pressurised return water regenerates electricity at times of use and also at times of high water demand and higher electricity demand. The boost pumped water being restored to the supply reservoir (29).

Such a system with a low head pressure but reasonable volume storage can supplement the through dam hydrogenation with the boost system water returned to the supply reservoir at times of drought or extended periods of electrical or thermal storage.

Claims

Claims 1 A boost pumped system of hydroelectric regeneration, in which boost pumps located at a high water storage reservoir level, take in water at the ambient reservoir pressure level and boost compress it to an increased pressure for injection into an existing conductor at the water storage level, or inject it to the top of a vertically extended conductor.
2 A boost pumped system according to claim 1 wherein the vertically extended conductor has a buffer tank and remote control centre to transmit control and operational data.
3. A boost pumped system according to claim 1 or claim 2 wherein the extended conductor is insulated against freezing.
4 A boost pumped system according to any preceding claim wherein the pumped hydro system is designed to take the increased electrical generation.
A boost pumped system according to any preceding claim wherein an existing or proposed hydro system only has low and uneconomical water storage potential, then such systems can be designed to have a boost pumped hydro system
6 A fresh water supply reservoir with through dam hydro generators can be supplemented with a boost pumped system according to any preceding claim and the operating free water can be returned to the original fresh water supply reservoirs, this can be an advantage at times of drought or excess water usage.
7 A boost pumped system according to any preceding claim wherein operation electricity power can be grid / green energy / self generated or from alternative energy storage systems.
8 A boost pumped system according to any preceding claim wherein the described boost pumping system can be designed to charge an alternative energy storage system other than reservoir water.
9. A boost pumped system according to any preceding claim wherein a boost pumped system is designed to operate with one or more through dam hydro generators.