WO2008118217A2

WO2008118217A2 - Generation of electricity and thermal energy from renewable energy sources

Info

Publication number: WO2008118217A2
Application number: PCT/US2007/084978
Authority: WO
Inventors: Norvell Nelson; Matthew Van Steenwyk
Original assignee: Norvell Nelson; Matthew Van Steenwyk
Priority date: 2006-11-17
Filing date: 2007-11-16
Publication date: 2008-10-02
Also published as: WO2008118217A3

Abstract

Cascade energy collection and containment devices are described herein and include: a) a renewable radiant energy source comprising at least one functional temperature energy unit, b) an energy extraction device, wherein the device collects the at least one functional temperature energy unit; and c) an energy storage device, wherein the storage device independently stores each of the at least one functional temperature energy units. Electricity generation devices are also described herein and include: a) the cascade energy collection and containment devices described, b) an expansion engine comprising a mechanical motion, and c) an alternator, wherein the alternator converts the mechanical motion to electricity. In addition, thermal energy generation devices are also described herein and include: a) the cascade energy collection and containment devices described, b) an expansion engine comprising a mechanical motion, and c) a converter, wherein the converter converts the mechanical motion to thermal energy.

Description

GENERATION OF ELECTRICITY AND THERMAL ENERGY FROM RENEWABLE ENERGY SOURCES, METHODS OF GENERATION AND USES

THEREOF

This application claims priority to United States Provisional Application Serial Number 60/859699 filed on November 17, 2006.

FIELD OF THE SUBJECT MATTER

The field of the subject matter is generation of electricity and thermal energy from renewable energy sources, methods of generation and uses thereof.

BACKGROUND

There is growing concern regarding climate change and the increasing levels of greenhouse gases in the atmosphere and their potential for accelerating the warming of the planet, Further, the rate of increase of atmospheric carbon dioxide, a greenhouse gas, is accelerating as the worldwide demand for electricity is rapidly growing as more countries begin to industrialize. Coal combustion remains the primary method for generation of electricity in the industrialized countries and is expected do so through this century and beyond. The projected increase in the use of coal will result in the acceleration in the amount of carbon dioxide in the atmosphere.

Many organizations have been exploring and developing technologies that can be used for generation of electric power without concomitant production of greenhouse gas emissions. Most visible among these are technologies such as wind power and solar photovoltaic (PV) technologies for conversion of solar-based energy directly into electrical energy.

These solar power technologies have experienced rapid growth during the past several years. While both wind power and solar PV have their respective advantages and enjoy the support of many organizations, they each have their own particular disadvantages. Wind power, for example, is typified by large structures that support the massive propellers needed to capture the solar energy in an economically usable manner. Such structures have an impact on the visual environment and are not readily accepted in urban areas. Further, wind power suffers from its inherent unpredictability and, as such, can not be considered as part of the base load generation infrastructure. Also, wind power generation systems are typically found in rural, more sparsely populated areas, and often at large distances from the electric grid.

Solar PV technologies are less obtrusive and have found widespread deployment in all areas of the country where suitable levels of solar insolation are available, especially in the southern portions of the US. As used herein, insolation means an act or an instance of exposing to sunlight. Solar PV technologies convert a fraction of the incident solar radiant energy striking their surfaces directly to electrical energy. The electrical energy produced is instantaneous and must be used as produced or be stored using some other technology. It's the storage of solar PV generated electrical energy that has been one of the barriers to deployment of the solar PV technology. Recent regulatory changes have in many areas removed this impediment by allowing the solar PV systems to be connected to the power grid so that unused electrical power generated may be "stored" on the grid. This recent option has increased the acceptance of the solar PV technology.

Most solar PV technologies are based upon the use of single crystal wafers of silicon for the active element in the deployed devices. The silicon devices are limited by the solid state physics of the device, which dictates that only a small fraction of the incident solar radiant energy can be converted to electrical energy.

Only the solar radiation having photon energies greater than the semiconductor band gap of the active element, which for silicon is about 1.1 EV, will be effective for electricity generation. The energy carried in photons with less energy than the band gap, as well as the "excess" photon energy above the band gap of the active element, is all converted to heat, not electricity. These thermal losses limit current

PV devices to about 22% efficiency for the best performing silicon devices in the development stage and a 17-18% efficiency range for commercially deployed units, Additionally, the conversion efficiency drops even lower as the PV materials heat up from solar thermal energy absorption. Of course, it is obvious that the solar PV devices only produce electrical energy when exposed to direct sunlight: and therefore, no power is provided during the night. Researchers in the field have turned their investigations into how to effectively use heat energy, such as that generated by solar PV materials. D. M. Clucas and J. K. Raine in "Development of a hermetically sealed Stirling engine battery charger" in Proc. Instn. Mech. Engrs (1994) 208, 357 has described the use of heat engines to generate electricity. Related disclosure of the application of Stirling engines are provided in US Patent Nos,: 6,637,312, 6,525,431. 6,220,030 and 5,630,351 ail issued to Clucas et. al., which disclose the design and use of external combustion Stiriing engines for the generation of electricity. The use, design and control of Rankine cycle heat engines for generation of electrical power and heat energy are disclosed by van de Loo in US 6,838,781 , US 2005/0091980 and 2006/6905227. All of these patents and published applications are hereby incorporated by reference herein.

Researchers sought to demonstrate combined heat and power or CHP generation for electricity generation, absorption cooling and water heating, (see J, Childress et. al., "Development of a Tri-Generation System", Florida State University, April 6, 2006) In these experiments, the heat source is waste heat from an internal combustion or IC engine. The electricity was generated using the IC engine as prime mover; the waste heat from the engine was used to drive the absorption cooler and to heat domestic water. While the operation of the several systems are demonstrated, the entire system does not represent an energy "cascade" in that two energy sources are used instead of one that "cascades" into many uses, the IC engine runs on the energy derived from gasoline combustion and the other two systems are driven by the waste heat from this process. Thus, this approach cannot be considered as a renewable energy system. US 6672064 issued to Lawheed describes a combined process to generate electricity using PV (photovoltaic panels) for both their ability to directly generate from sunlight and to capture the heat deposited in such panels by solar insolation. The rise in temperature allowed in such PV panels is normally restricted to temperatures of 50C or less owing to the strong temperature effect on the PV performance. This temperature of 50C is not sufficient to economically drive an ORC engine to produce electricity.

Methods for collecting energy have been developed and used for many years to heat water for bathing and washing. In addition, reflective concentrators have been developed to facilitate energy extraction, however, with the express purpose of heating water for domestic purposes (see Ritter-Solar). In addition, the Swiss government testing organization for solar technologies (Solar Collector Factsheet: SPF- Nr. C625, Diestrol Power. (Solartechnik Prϋfung Forschung, www.solarenergy.ch,), shows a vacuum tube solar collector that is silvered on the inside for reflection of incoming solar insolation onto the collector. The description of the collector design and placement does not indicate that concentration of the solar energy was a major feature, or even a consideration of the tube design, and the shape of the inner tube (cylindrical) would indicate that the design was not intended to limit black body radiation losses, a function of collector area (pi x diameter x length) versus a flat plate collection surface, which collects equally well with the non-imaging focus of a semi-circular collector and would only emit black body radiation as a function of 2 x diameter x length. Finally, external concentrators, usually of parabolic design, have been added for the purpose of elevating temperatures of the collection fluid to drive a Rankine Cycle (steam) turbine and generator (>700 F), however, these elaborate and costly reflectors are found on 'utility sized' electrical production systems and typically only drive one extraction device, require constant input to follow the sun and need constant maintenance. Thus, based on the various technologies that have been developed, there are still several needs in the field of renewable energy sources, such as a) the ability to utilize renewable energy sources, such as solar radiant energy, in a cascading arrangement to collect and store energy, b) the ability to utilize the collected and stored energy in a variety of energy extraction devices for electricity, air conditioning, domestic space heating and wafer heating, c) the development of materials and devices that facilitate the collection, storage and use of this energy, d) the ability to have a stationary extractor that does not need to be reset or repositioned to follow the sun, e) the goal of being relatively maintenance free, and f) the ability to decentralize the power generation. SUMMARY OF THE SUBJECT MATTER

Cascade energy collection and containment devices are described herein and include: a) a renewable radiant energy source comprising at least one functional temperature energy unit, b) an energy extraction device, wherein the device collects the at least one functional temperature energy unit; and c) an energy storage device, wherein the storage device independently stores each of the at least one functional temperature energy units.

Electricity generation devices are also described herein and include: a) the cascade energy collection and containment devices described, b) an expansion engine comprising a mechanical motion, and c) a converter, wherein the converter converts the mechanical motion to electricity.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a contemplated embodiment in its most basic form. The operations present in Figure 1 include heat collection, heat storage, and energy extraction. Figure 2 is an expanded version of the embodiment in Figure 1 and illustrates the concept of the "cascading" use of collected renewable energy, such as radiant energy, solar radiant energy or solar thermal energy, in which the energy is supplied to an energy extraction device and stored as different temperatures as functional temperature energy units at the functional temperature most suitable for that particular energy extraction device.

Figure 3 shows a contemplated thermal energy cascade concept in operation with a second thermal energy storage tank.

Figure 4 is operationally equivalent to the cascade process shown in Figure 3 with the addition of an alternate heat source, HX-6. The predicted maximum available daily and annual solar insolation for

35.14°N latitude and 120.59° W longitude (Arroyo Grande, CA) is shown in Figure

5.

The energy distributions for the best solar day of the year, in the northern hemisphere, June 21 , are illustrated in Figure 6, The energy distributions for the "average" solar day of the year, Mar/Sept 21 , are illustrated in Figure 7.

The energy distributions for the shortest day of the year, Dec 21 , are presented in Figure 8.

The removal of the intake valve lifter arm and the replacement of this single lobed cam (not shown) with the double lobed cam 910 shown in Figure 9 allowed the exhaust valve (not shown) to open on every upstroke.

The initial construction of a 4 tube array 1010 is shown (in part) in Figure 10.

The temperature of the inlet manifold to the array was measured as a function of time, and the results are shown in Figure 11. In Figure 12, array 1210 comprises a partial pipe 1220, a reflector material 1230 and a collector tube 1240. The array is supported by support structure 1250,

Figure 13 shows an exploded view of the array 1310 comprising a partial pipe 1320, a reflector material 1330 and a collector tube 1340. The support structure 1350 is shown in this Figure.

DETAILED DESCRIPTION

Surprisingly, new devices, methods and processes have been developed for the field of renewable energy sources, such as a) the ability to utilize renewable energy sources, such as solar radiant energy, in a cascading arrangement to collect and store energy, b) the ability to utilize the collected and stored energy in a variety of energy extraction devices for electricity and thermal energy, such as air conditioners, domestic space heating and water heating, c) the development of materials and devices that facilitate the collection, storage and use of this energy, d) the ability to have a stationary extractor that does not need to be reset or repositioned to follow the sun, e) the goal of being relatively maintenance free, and f) the ability to decentralize the power generation.

Electricity generation devices are also described herein and include; a) the cascade energy collection and containment devices described, b) an expansion engine comprising a mechanical motion, and c) a converter, wherein the converter converts the mechanical motion to electricity. As used herein, the term "converter" refers to those devices, such as an alternator, DC generator that convert mechanical motion or rotary motion to electrical energy.

In one embodiment, a novel mode of operation of a renewable energy capture, thermal energy or heat storage, and parsed or cascading energy usage system is described in which the driving forces are obtained by absorption of this renewable energy and its subsequent conversion to functional heat or thermal energy in a useful form, in some embodiments, contemplated renewable energy comprises solar radiant energy, or other thermal energy sources. The converted functional heat or thermal energy can then be transferred into a plurality of energy or heat storage vessels, which may be collected and stored at different temperatures (functional temperature energy units), for useful extraction of energy at times most suitable for its productive use.

There are many advantages that the combination of the heat storage capability coupled with the multiplicity of heat driven unit operations provides, including the surprising advantage for the user of choice with respect to both the energy sources and energy operations for individual selected applications.

More specifically, contemplated embodiments comprise a series of energy or heat storage vessels that are charged by circulating heat transfer fluid, which is heated through the collection and absorption of renewable energy, such as radiant energy or solar radiant energy. This energy may be converted to functional heat which is absorbed by the heat transfer fluid. The storage vessels can be arranged such that each may store thermal energy at different functional temperatures or energy units. Further, the storage of the thermal energy for its use in various applications at demand times rather than only being available during hours of active solar insolation is an major advance over systems, such as solar PV, that only function when the sun shines.

In some embodiments, consumers - typically a commercial or residential building - are provided with energy for their various operations, including air conditioning needs, space heating needs, hot water needs and electrical energy needs through use of stored thermal energy. The stored thermal energy, in turn, is derived from the capture of renewable energy, such as radiant energy, or solar radiant energy, and its conversion to functional heat, which is transferred to the heat storage vessels. The thermal energy may be stored in the vessels as functional heat, latent heat or a combination of both. The ability to store thermaf energy in the storage vessels at different functional temperatures allows the user to have the ability to match the energy stored to the actual need of the individual application for energy. For example, the thermal storage tank used for a space heating application may be set at 40C (104F), which then can supply heat at a safe but effective temperature for this application. Similarly, other storage temperatures can be set to match the needs of other applications such as hot water heating and electricity generation. Figure 1 shows a contemplated embodiment in its most basic form. The operations present in Figure 1 include heat collection (EQ-1), heat storage (T-1 ), and energy extraction (EQ-2, HX-1 and T-2). In this particular embodiment, a Solar Collector EQ-1 is shown and "P" designates various piping, In some embodiments, the solar collection heat source could be augmented with or replaced by a burner with a fuel, such as natural gas, landfill gas, or biodigester gas or waste heat from an internal combustion engine and still remain within the scope of the embodiments described herein.

Figure 2 is an expanded version of the embodiment in Figure 1 and illustrates the concept of the "cascading" use of collected renewable energy, such as radiant energy, solar radiant energy or solar thermal energy, in which the energy is supplied to an energy extraction device and stored as different temperatures as functional temperature energy units at the functional temperature most suitable for that particular energy extraction device, in this embodiment, solar thermal energy is collected by the EQ-1 solar collector and is converted to functional heat with a suitable heat transfer fluid. The collected energy exits the collector at its highest

"quality" level and is best matched for use in either the high temperature storage tank or for driving the heat engine, EQ-2, for generation of electricity.

Specifically, in Figure 2, the return, to tank T-1 , of the heat transfer fluid exiting tank T-2, the high temperature thermal storage tank can take either of two routes depending on the control valve positions. The first option allows for a direct return of the fluid to tank T-1 when valve V-5 is closed and valve V-6 is open via piping defined by P-9 and P-11. The second option allows the fluid to pass through heat exchanger HX-3 in tank T-3 when valve V-5 is open and valve V-6 is closed through piping defined by P-9, P-10 & P-11. The second option allows for heat transfer from the fluid to the hot water tank T-3 where excess functional heat of the fluid may be stored.

The heat engine EQ-2 can be driven using either or both of 2 high temperature fluid sources depending upon the respective positions of the 2 control valves V-3 and V-4, The thermal energy stored in the high temperature tank T-2 is used to drive the heat engine EQ-2 when valve V-3 is open and valve V-4 is closed. The heated fluid is then passed through open valve V-3 using pipe P-5 to heat exchanger HX-1 and returned to tank T-2 via pipe P-8. Optionally when, for example, the stored thermal energy in tank T-2 is at maximum capacity of the eutectic, the heat engine EQ-2 can be driven directly from the fluid outflow from the solar collector EQ- 1 via pipes P-6 and P-7 which allows the fluid to flow through heat exchanger HX-1 when valve V-4 is open and valve V-3 is closed. The return flow in this instance passes also through pipe P-8 back into tank T-2. Optionally, both heated fluid sources form EQ- 1 and T-2 may be used if valves V-3 and V-4 are used as metering valves to partition the fluid flow between the routes defined by pipe P-5 and piping P-6 and P-7.

The low temperature side of the heat engine EQ-2 is provided by fluid flow passing through heat exchanger HX-2. In this loop tank T-1 , the low temperature eutectic heat storage tank, is used to provide the low temperature heat sink for the heat engine. The use of the fluid from tank T- 1 as the low temperature fluid allows for operation of the heat engine to occur over a known and controlled temperature differential. The fluid in the low temperature loop is pumped from tank T-1 with pump P-2 through pipes P-12 and P-13 to the low temperature heat exchanger HX-

2. The return flow to tank T-1 is being routed through pipes P-14 and P-15.

The thermal energy stored in tank T-1 , the low temperature storage tank, may be pumped into the space heating loop using pump P-3 through a piping loop that enters the space heating loop via pipe P-17 when valve V-7 is open and valve V-8 is closed. The return route for the space heating loop is provided by pipe P-18. The space heating loop is also fitted with a bypass loop to allow for alternate cooling of the fluid in tank T-1. This alternate cooling loop becomes functional when valve V-7 is closed and Valve V8 is open which allows the fluid to pass through heat exchanger HX-5 via pipe P-19. Optionally, both space heating loops may be used if valves V-7 and V-8 are used as metering valves to partition the fluid flow between the routes defined by pipe P-19 and piping P- 17 and P-18.

The stored thermal energy of tank T-1 can also be used to pre-heat the incoming domestic water before it enters the hot water heater, T-3. The incoming water is carried by pipe P-20 through heat exchanger HX-6 before going to tank T-3 via pipes P-21 & P-22. The hot water is delivered to the use points from T-3 via pipe P-23. The heat engine EQ-2 is driven by the temperature differential established by the above described fluid flows. The heat engine EQ-2 is used to drive the AC alternator EQ-3 which converts the mechanical motion of the heat engine EQ-2 to electricity. The combination of the heat engine EQ-2 and the alternator EQ-3 allow for the conversion of the thermal energy captured from the solar radiant energy to be converted to electricity. The electric power produced by the alternator is routed to the eiectricity control box INST-1 for distribution as needed.

The electricity control box INST-1 serves several functions in the overall process. The control box INST-1 accepts the AC electricity generated by alternator EQ-3 delivered by the circuit comprising wires W-1 and W-2. This electric power can be delivered for on-site use via the circuit containing wires W-11 and W-12 or delivered to the grid via the circuit defined by wires W-3 and W-4 depending on the relative demand of the on-site consumption of power. If power generation by the alternator EQ-3 is greater than the on-site demand, power is furnished to the grid, if the on-site demand for power exceeds the power generated by the alternator EQ- 3, the gird is used to supplement the on-site generated power to meet the local demand.

!n order that the local system can be connected to the grid the voltage and frequency of the on-site generated power needs to be conditioned to match the exact parameters of the grid power at the time of connection. Consequently, the control box is also required to function as the AC power conditioner which wilt allow the on-site process to connect to the grid.

The connection to the grid requires that the on-site power generated by alternator EQ-3 match the grid power in both frequency and voltage. The frequency control of the on-site generated power requires control of the field strength of the alternator EQ-3 using the control wiring shown as W-9 and W-10.

The frequency of the power being generated is dependent on the rotational speed of the heat engine which is controlled from INST-1 via the wiring loop shown as W-

7 and W-8. The wiring loop, shown as W-5 and W-6, connecting the control box INST-1 to the resistive heating element RES-1 in the hot water heater T-2 serves 2 functions, first it supplies back-up power for heating the domestic hot water, if needed, and second it acts as a momentary electric power sink for the control box as adjustments are made to the on-site power to match grid power conditions, Finally, the control box is connected to a back-up battery, BAT-1 , which allows for back-up ability or field strength control of alternator EQ-3 on start-up of electricity generation,

In some embodiments, the workable heat engines for a system such as that represented by Figures 1 or 2 could include Stirling engines, Rankine cycle turbines, Organic Rankine Cycle turbines (ORC), or other type of expansion engine,

Ericcson cycle engines, steam engines, other Carnot cycle engines and combinations thereof. The heat engine may also be replaced by or augmented by thermally driven adsorption cooling device, including such systems as absorption coolers, desiccant cooling systems, evaporative coolers, and compression chillers.

Again, this list is meant to be representative rather than exhaustive.

The heat engine exhausts the heat transfer fluid at a lower temperature compared to the input temperature and this differential represents the energy "extracted" by the heat engine. The "quality" of heat energy in this exhaust stream, although reduced, is of sufficient "quality" at 150C to be matched to the input temperature requirements of a thermal (absorption) air conditioning energy extraction device HX-1. This device, in turn, reduces the "quality" of the heat energy in its exhaust stream, compared to the input, to a "quality" level that matches the energy input requirement for domestic hot water and/or space heating needs. The exhaust stream from this final energy extraction process(es) has been further degraded and is now recycled to the solar collector for re-heating to the higher energy "quality" level. This concept of matching the energy quality needs of the individual energy extraction device to the "quality' of the incoming energy stream is an example of the energy "cascade" principle in which the "quality" of the energy available is matched to the "quality" of energy required by the specific energy extraction device.

Further, the source of the thermal energy may also include boilers fired by fossil fuels, such as natural gas and oil. as well as biofuels, such as gases derived from digestion of agricultural wastes including manures, landfill generated gases and flare gas combustion derived from fossil fuels operations. Contemplated thermal energy may also comprise a combination of those mentioned herein. Even though Figure 2 shows the presence of three thermal energy storage tanks, it is not necessary to limit contemplated embodiments to only three tanks. The use of more tanks or fewer tanks at different or the same temperatures still falls within contemplated embodiments. Figure 3 shows a contemplated thermal energy cascade concept in operation with a second thermal energy storage tank. The heat transfer fluid is moved through the entire piping circuit by Pump-2 shown feeding the solar collector - EQ-4. In Figure 3 the operation of the entire system is shown under the control of the I-1 control box. The I-1 control box, programmed by the user, controls the distribution of the energy contained in the heat transfer fluid via operation of the piping on/off valves at V-1 , V-3, V-5, V-7 and V-9 and by control of the mixing valves V-2, V-4, V-6, V-8 and V-10 via the electrical connections shown, it is well known in the art, that proper sequencing of such valve combinations can be used to independently control the flow of the heat transfer through each of the energy storage devices and each of the energy extraction devices to provide the desired energy fiows to each end use.

Further, the control box, I-1 , is also in communication with the individual control boxes on the energy extraction devices; controller I-2 controls the generator and manages the tie to the electric grid; controller I-3 controls the operation of the air conditioning unit; controller I-4 manages the control of the domestic heating system; and, instrument box I-5 allows for connection of the entire system to the web for off-site monitoring and control. The main controller, I-1 , also has ties to the heat storage vessels to monitor their status,

The solar thermal energy is collected in solar collector EQ-4 where it is converted to functional heat in the heat transfer fluid. The heat transfer fluid exits the solar collector having the highest "quality" energy available in the system. This high "quality" energy stream can be stored in the high temperature heat storage tank, T-; or directed towards the heat engine, EQ-6, where it is converted to electricity by generator, EQ-7; or, parsed between these two high "quality" energy devices under the control of the I-1 control box, depending upon the actual energy needs of the moment. In similar fashion, the next energy extraction device in the cascade, the absorption A/C, HX-2, has the heat transfer fluid directed towards it under the control of I-1 according to the air conditioning needs of the moment and the availability of energy in the heat transfer fluid. In like manner, the lower quality heat energy exhausted from the air conditioning unit, HX-2, is, under control of I-1 , parsed between use by the energy devices represented by T-5, the domestic heating unit operations and T-4, the lower storage tank. Finally, the energy depleted thermal transfer fluid is recycled back to EQ-4, the solar collector system, for recharging to the higher quality energy state. Figure 3 describes one embodiment of an energy cascade concept, but it should be understood that there are many other contemplated embodiments. For example, under the description given above, each of the energy extraction devices that are connected in series could also be independently connected to the heat storage devices by separate heat transfer loops and be considered as a contemplated embodiment.

Figure 4 is operationally equivalent to the cascade process shown in Figure 3 with the addition of an alternate heat source, HX-6. The alternate heat source can be any source of thermal energy such as, but not limited to, a burner with a fuel such as natural gas, landfill gas, wood pellets, or biodigester gas or other source of heat, such as the exhaust from internal combustion engines and combinations of any of the above.

The provision of the type and size of any installed alternative thermal energy source would be anticipated to be a function of the normally available sunshine at climate at the particular location of the system and the capacity of the installed heat storage facility. The availability of sofar thermal energy is variable over time and is a function of time of year, time of day and focal weather conditions. The diurnal and seasonal variation in available solar insolation is readily predictable and is calculable. The predicted maximum available daily and annual solar insolation for

35,14°N latitude and 120.59° W longitude (Arroyo Grande, CA) is shown in Figure 5. As is shown in Figure 5, more solar energy is available in the summer compared to the winter. The forecast for solar energy availability, as shown, is the maximum available at any given day or hour. The actual amount of capturable solar energy is a function of the date and time as wetl as the local weather conditions such as rain, fog or clouds any of which will lower the solar insolation. The energy "cascade" system described herein is designed to somewhat ameliorate the deficiencies and disadvantages inherent in any solar energy collection and use system. First, the system incorporates one or more storage units for solar thermal energy to allow for operation after sundown or during periods of inclement weather. The intelligent control box, I-1 , of the system also allows for optimizing the usage of the available solar among the various heat extraction devices to gain maximum benefit from the solar thermal energy harvested. The intelligent controller balances forecasted solar energy collected with anticipated energy needs in light of the projected unit operations efficiency shown in Table 1. Potential process scenarios for summer, spring/fall and winter are presented in Figures 6-8, respectively, as discussed in the Examples Section for a 100 square meter system.

EXAMPLES EXAMPLE 1

The energy distributions for the best solar day of the year, in the northern hemisphere, June 21 , are illustrated in Figure 6. The solar source is projected to provide an insolation of 837 kW-hr for the day of which 65% or 544 kW-hr as functional heat is collected in the system. The highest priority energy use is for air conditioning as this need is most pronounced in the heat of the day which is the peak (usage and rate) period for the electric utility. This need is covered along with the more modest energy need for hot water at 12.8kW-hr, All left over heat energy is directed towards electricity generation, while the least efficient unit operation, the availability of "surplus" thermal energy is exploited by conversion to electricity. The overall efficiency of energy capture for this summer day is estimated at 32%, predominantly as a result of the conversion of part of the collected energy to electricity.

The energy distributions for the "average" solar day of the year, Mar/Sept 21 , are illustrated in Figure 7, The solar source is projected to provide an insolation of

594 kW-hr for the day of which 65% or 386 kW-hr as functional heat is collected in the system. Spring and Fall days at this example location are usually very temperate; space heating or air conditioning needs are rarely required. Thus, after the modest requirement for domestic hot water at 12.8kW-hr is met, the remainder of the collected energy can be converted to electricity at 70 kW-hr. Owing to the large generation of electricity, the overall estimated efficiency of the system falls about 14%. (This conversion efficiency number would be respectable for a commercial solar photovoltaic system, the cascade system deliver this efficiency along with the hot water need.)

The energy distributions for the shortest day of the year, Dec 21 , are presented in Figure 8. The solar source is projected to provide an insolation of 261 kW-hr for the day of which 65% or 169 kW-hr as functional heat is collected in the system. Winter days at this example location are can be chilly; thus space heating needs are required. Thus, after the modest requirement for domestic hot water at 12,8kW-hr is met, the remainder of the collected energy, 152 kW-hr, is consumed for space heating. No air conditioning or electricity operations are activated. The overall efficiency of the system in this operating scenario is estimated to be 66%.

All of the unit operations, except for two (2), in the energy "cascade" are commercial or very near commercial units that can readily be adapted for use in this invention. The two (2) unit operations that required additional adaptation for operation under the process conditions available with the energy cascade are the heat engine and the solar collector array. Both of these unit operations were made functional by distinctive design modifications to commercial units. The design improvements to the commercial units to allow for their functionality in the cascade system are also incorporated here in some contemplated embodiments.

THE "HEAT" ENGINE

The "heat engine" in this immediate case is a term used to describe a mechanical device that can transform heat energy into mechanical motion. As mentioned, examples of such heat engines include steam engines, steam turbines, ORC (organic Rankine cycle) turbines, vane motors or any like mechanical device that can use the expansion of a hot gas as a driving for development of mechanical motion. It is anticipated that the "heat engine" useful in this application will be an engine running an organic Rankine cycle. An ORC is a heat driven cycle that uses thermal energy to heat an organic fluid to a temperature such that the vapor pressure of the organic material is raised to several hundreds of psi (14.5 psia = 100 kPa) at temperatures compatible with solar thermal energy collectors. A preferred organic liquid for this application is Genetron 245fa, a product of Honeywell. This organic material (1 ,1 ,1 ,3,3- pentafluoropropane) has a vapor pressure of 505.3 psia at 505°F (3380 kPa at 150°) which makes it useful for this application.

The listing of potentially useful heat engine types was given above. In addition to acting as a gas expansion device a suitable heat engine has to take the heat and pressure of the working fluid at 3380 kPa and 150°C. The devices noted above did not, in general, meet one or both of the temperature pressure criteria. As part of this invention it is to be noted that a suitable "heat" engine for the practice of this invention can be derived from a standard, commercial internal combustion (IC) engine such as represented by the Honda GX-25 engine. The Honda GX-25 engine is a 25 cc 4-stroke IC engine commonly used for "weed whackers".

The GX-25 engine was converted to a gas expansion device by making the following modifications to the engine: the intake valve was rendered inoperable by removal of the valve lifter: the spark plug was replaced by a solenoid valve for injection of the pressurized driving fluid; and, the redesign of the overhead cam that drives the valve lifters by modifying the cam to open the exhaust valve on each upstroke, thereby converting the 4-stroke IC engine to a 2-stroke gas expansion engine.

The original equipment cam for the GX-25 has a single lobe that lifted both the intake valve on every other down stroke and the exhaust valve on every other upstroke. The removal of the intake valve lifter arm and the replacement of this single lobed cam (not shown) with the double lobed cam 910 shown in Figure 9 allowed the exhaust valve (not shown) to open on every upstroke. Figure 9 shows the double lobed cam 910 is attached to a gear 920 that operate together. The front view 905 of the double lobed cam 910 and the gear 920 also shows a shaft opening 930. The side view 907 shows the details of the gear 920, along with a side view of the double lobed cam 910. The back view 909 shows the shaft opening 930 and the gear teeth 935, which are blown up for reference in exploded view 911. The numbers in parentheses are represented in millimeters. Power in the heat engine was generated through injection of a pressurized fluid at the top of every stroke. The timing of the pressurized fluid injection is correlated with the engine's rotation and is typicafly selected to occur after top dead center (TDC).

In the test model the engine shaft was fitted with a pointer which rotated with the shaft and which positioned such that its presence would be detected by a proximity sensor. The triggering of the proximity sensor and the firing of the solenoid injector valve was controlled by a suitably programmed computer. For the initial testing the engine was driven by compressed air at an intake pressure of about 100 psig (690 kPa) at ambient temperature 75°F (24°C), The computer program allowed for the rotation sensor input timing and solenoid valve opening permitting a sustained operation of the "heat" engine at around 1200 rpm. The "heat" engine was loaded with a DC permanent magnet generator to provide a measurable electrical output. One instance of the operation of this heat engine generator combination is presented in this example.

THE SOLAR COLLECTOR DESIGN

The energy cascade principle requires that the solar insolation be captured as "high quality" thermal energy which means that the preferable temperature of the heat transfer fluid leaving the solar collector needs to be in the range of 175°C to 200°C (350°F to 390 F°) although lower temperatures are certainly acceptable for operating the air conditioning and domestic energy extraction devices. The collection of solar thermal energy at these elevated temperatures requires some concentration of the solar insolation to achieve the target temperatures at reasonable efficiencies. The science and technology of the concentration solar radiation is thoroughly covered in the monograph by Winston, et. al. (see R. Winston, J. C Minano and P. Benitez. "Non-imaging Optics, Elsevier Academic Press, Burlington, MA, 2005). The concepts taught by Winston et. al., are incorporated in the designs discussed here.

The concentration of solar thermal energy for generation of electricity is not a new concept. Electric power stations have been operating the California desert for decades with several new similar large scale operations in the planning stage

(http://www.greentechmedia.com/articles/cooling-with-the-sun.html "Vinod Khosla thinks solar thermal can slow global warming" By; Jennifer Kho, September 4, 2007). All of these operations are characterized by large area installations of tracking (follow the sun's path) parabolic mirrors that offer high concentration ratios of the incoming solar radiation such that temperatures in the heat collection fluid reach to temperatures of 400°C (750°F). These temperatures are attained with concentration ratios of 10 or more.

The collection efficiency of the solar collector tube as used in this invention is a defined by the quotient of energy collected divided by the energy of the incident solar insolation. The energy collected is, in turn, determined by the energy absorbed less the energy losses. The vacuum collector virtually eliminate all losses due to heat conduction and convection; the remaining losses are reflection (rather than absorption) by the glass and reflector surfaces; absorptive losses at the collector surface; and, re-radiation (black body) from the collector surface. The black body losses are the major loss factor for the higher temperatures and are defined by the Stefan-Boltzmann equation, Equation 1 (Ref 1 ).

Q_{radiative loss per unit area} =εσ (T_absorber ⁴ -T_ambient ⁴ )

Where: ε= the emissivity of the surface, typically 0.9 to 0.95 σ = the Stefan-Boltzmann constant 5.6699 x 10^-8 W m^-2 K^-4

The radiative losses predicted by the Stefan-Boltzmann equation become increasing onerous as the temperature of the collector warms above ambient, note the 4^th power relationship. The concentration of the incoming radiation onto an absorber reduces the radiative losses predicted by the Stefan-Boltzmann relationship by the concentration ratio. The actual concentration achieved will be determined by measurement, concentration ratios in the range of 2-3+ can be obtained. Concentration ratios in this range allow for collection at efficiencies in the 60-70% range. While the integral semi-circular reflector-collector does not attain the concentration ratios available with the compound parabolic reflectors developed by Winston, et. al. that are functionally much simpler as the reflector and collector structures are part of the same environmentally stable package. This integral design allows for simplicity and freedom of design for architecturally friendly deployment.

Work from of the Motor

Assuming, (Isentropic, no kinetic or potential effects, & S1=S2) One compression cycle per revolution

System Pressure P ₁ :=( 100+ 14.7) ·psi P ₁ = 7.90810⁵ Pa

System Temperature TC1 :=(25+ 273.15)·K TC1 = 298.15K Motor Speed Gas Density

Motor Volume

Motor Compression Ratio V ₂ = 25.015cm³ C _ratio := 7.5 V₁ = 3.335 cm³

System Outlet Pressure P ₂ = 15.293psi absolute P ₂ - 14.7psi = 0.593psi

gauge

Exhaust Temperature TC2 = 167.655K

Mass Flow Rate kg/min Mass = 0.03·gm

Mass _flow := RPM Mass

Flow Rate (STP)

Work Performed by the Motor

Electrical Power from System V*l = Power

Voltage ;=5·V Current :=0.96amp

W2 := Current· Voltage Power from System W2 = 4.8 W

Initial Power to the Motor q _{1 2} = 74.756watt

Overall System Efficiency SystemEffeciency = 6.421·%

Motor to Generator Efficiency MotorEfficiency = 12.829·%

EXAMPLE 2

A semi-circular concentrator design was used, as this design is more easily constructed in a garage operation and vacuum absorber tubes with the flat collector coated with the absorber material on both sides were easily obtained. The semicircular collector concentrates the incoming radiation to a plane rather than to a line like the parabolic collectors. The vertical dimension of this focal plane is equal to r/2 or ½ the radius of the semicircular reflector.

The collector tubes were furnished on special order by Sunda Solartechnik as the Seido 2 Vacuum Tube. The collector plate has a height of 90mm, as r/2 this would indicate that a reflector have a radius of 180mm (7.08"). We approximated this by using a 16" od PVC pipe section. The pipe has a ½" wall thickness so the inside diameter was about 15", close to the 2 x (7.08") needed for perfect fit. The initial construction of a 4 tube array 1010 is shown (in part) in Figure 10. For ease of construction complete circular sections of the pipe 1020 were left in the structure as supports. A 1/3 section (120°) 1030 of the pipe 1020 was used to support the reflective material 1040, silver on Mylar, 5 mil thickness.

The Seido 2 collectors 1050 have a flow through design for the thermal transfer fluid as can be seen (inferred) from the brass collector fittings on the ends of the tubes. The heat collector fluid is pumped into the center tube and is returned out through the tee on the side. The tubes are connected in a manifold to allow for circulation through al the tubes. Two arrays of 4 tubes each were used.

The two arrays of tubes were mounted in the rack at a 40° elevation towards the south, actual azimuth orientation was about 15°-20° east of south. The aperture per tube was 13 inches wide by 79 inches long less the obstruction of the circular supports [(2 x 4") + (2 x 2") = 12"]. This dual array was exposed to the sun on November 3, 2007, to measure solar energy uptake. The temperature of the inlet manifold to the array was measured as a function of time, and the results are shown in Figure 11. The heat transfer fluid employed was 15 gallons of peanut oil.

Following this test, the arrays were modified by removal of the overhead sections of the PVC pipe support, as their presence shades about 15% of the reflector at any given time. The resulting structures are shown in Figures 12 and

13. In Figure 12, array 1210 comprises a partial pipe 1220, a reflector material 1230 and a collector tube 1240. The array is supported by support structure 1250, Figure 13 shows an exploded view of the array 1310 comprising a partial pipe 1320, a reflector material 1330 and a collector tube 1340. The support structure 1350 is shown in this Figure. The structural component of the overhead pipe section was replaced by pieces of "All-Thread" running through the end sections. Unfortunatefy, persistent foggy weather since this structural modification was made has precluded the collection of any data from any run of significant time duration.

General Reference Materials: Granet and M. Bluestein, "Thermodynamics and Heat Power", 7^th edition, Pearson Prentice-Hall, Upper Saddle River, NJ, 07458, 2004

J. A. Duffie and W. A. Beckman, "Solar Engineering of Thermal Processes", 3^rd edition, John Wiley and Sons, Hoboken, NJ, 2006

R, Winston, J. C. Minano and P. Benitez, "Non-imaging Optics, Elsevier Academic Press, Burlington, MA, 2005

Thus, specific embodiments, methods of generation of electricity and thermal energy from renewable energy sources, and uses thereof have been disclosed, it should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure herein. Moreover, in interpreting the specification and claims, ail terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.

Claims

CLAIMSWe claim:

1. A cascade energy collection and containment device, comprising: a renewable radiant energy source comprising at least one functional temperature energy unit, an energy extraction device, wherein the device collects the at least one functional temperature energy unit; and an energy storage device, wherein the storage device independently stores each of the at least one functional temperature energy units.

2. The cascade energy collection and containment device of claim 1 , wherein the renewable radiant energy source comprises sofar radiant energy.

3. The cascade energy collection and containment device of claim 1 , wherein the renewable radiant energy source comprises at least two functional temperature energy units.

4. The cascade energy collection and containment device of claim 1 , wherein the energy extraction device and the energy storage device are contained within one device.

5. The cascade energy collection and containment device of claim 1 , wherein the energy extraction device comprises an energy concentrator.

6. The cascade energy collection and containment device of claim 5, wherein the energy concentrator comprises at least one collector tube having an internal reflector.

7. The cascade energy collection and containment device of claim 6, wherein the internal reflector comprises a substantially flat, double-side coated absorber plate.

8. The cascade energy collection and containment device of claim 6, wherein the internal absorber plate has a height equal to half of the radius of the at least one collector tube diameter.

9. The cascade energy collection and containment device of claim 1 , wherein the energy storage device is charged by a circulating heat transfer fluid.

10. The cascade energy collection and containment device of claim 1 , wherein the energy extraction device is controlled by a control box.

11. The cascade energy collection and containment device of claim 10, wherein the control box chooses the quantity of energy units extracted from the source based on need, local weather conditions, remote activation or a combination thereof.

12. The cascade energy collection and containment device of claim 10, wherein the control box has remote operating capability.

13. The cascade energy collection and containment device of claim 12, wherein remote operating capability includes communication with a local power grid.

14. An electricity generation device, comprising: the cascade energy collection and containment device of claim 1 ; an expansion engine comprising a mechanical motion, and a converter, wherein the converter converts the mechanical motion to electricity.

15. The electricity generation device of claim 14, wherein the expansion engine is a two-stroke engine.

16. The electricity generation device of claim 14, wherein the converter comprises an alternator or a DC generator.

17. The electricity generation device of claim 14, wherein mechanical motion comprises rotary motion.

18. The electricity generation device of claim 14, wherein the expansion engine comprises a Stirling engine, a Rankine cycle turbine, an Organic Rankine Cycle turbine (ORC), and Ericcson cycle engine, a steam engine, a Carnot cycle engine or a combination thereof.

19. An electricity generation device, comprising: the cascade energy collection and containment device of claim 1 ; a thermally driven adsorption cooling device comprising a mechanical motion, and a converter, wherein the converter converts the mechanical motion to electricity.

20. The electricity generation device of claim 19, wherein the cooling device comprises an absorption cooler, a desiccant cooling system, an evaporative cooler, a compression chiller or a combination thereof.