WO2012110758A2

WO2012110758A2 - Solar energy device

Info

Publication number: WO2012110758A2
Application number: PCT/GB2012/000148
Authority: WO
Inventors: Paul Anthony LAIDLER
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-02-16
Filing date: 2012-02-15
Publication date: 2012-08-23
Anticipated expiration: 2013-08-16
Also published as: EP2676299A2; GB201313763D0; GB2502719A; GB201102677D0; WO2012110758A3

Abstract

A solar energy device has an electrical generator for converting at least a portion of solar energy into electrical energy. Furthermore, a thermal transfer element is providing for transferring at least a portion of heat energy from the sun to a body. The thermal transfer element is thermally connected to the electric generator.

Description

Solar Energy Device

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from [United Kingdom Patent Application No 11 02 677.0 filed February 16^th, 2011, the entire disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a solar energy device, and in particular a generator suitable for generating heat and/or electrical energy.

2. Description of the related art

One type of existing solar energy device comprises a panel often referred to as a solar thermal panel which is adapted to utilise heat energy from the sun to directly heat water.

While solar thermal panels are widely used, they suffer from a number of disadvantages, in particular poor heat transfer to the water. This problem has been addressed to an extent by the implementation of improved fluid pumping systems to transfer heat energy from the sun to the water. However, such fluid pumping systems can be complex and therefore costly.

Another type of existing solar energy device comprises a panel often referred to as a photovoltaic panel which is adapted to convert solar energy into electrical energy, which can be either stored in a suitable storage device and then used as required, or transferred to the national electricity network for example.

Again, whilst photovoltaic panels are widely used, they suffer from a number of disadvantages, in particular a reduction in efficiency as their temperature increases. This problem has been addressed to an extent by the implementation of improved cooling systems. However, such cooling systems can significantly increase the cost of the photovoltaic panel as a whole.

BRIEF SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention there is provided a solar energy device comprising: -

(i) an electrical generator for converting at least a portion of solar energy into electrical energy;

(ii) a thermal transfer element for transferring at least a portion of heat energy from the sun to a body,

wherein the thermal transfer element is thermally connected to the electrical generator.

It will be understood by persons skilled in the art that solar energy is comprised of heat energy and light energy.

The thermal transfer element may be directly thermally connected to the electrical generator.

The electrical generator may compris at least one photovoltaic cell for converting at least a portion of light energy from the sun into electrical energy.

A photovoltaic cell works on the principle that a potential difference is created on account of exposure of the cell to light energy from the sun. In this way, a photovoltaic cell converts light energy into electrical energy.

Alternatively, the electrical generator may comprise at least one thermoelectric generator for converting at least a portion of heat energy from the sun into electrical energy.

The thermoelectric generator comprises a Seebeck device. A Seebeck device works on the principle that a potential difference is created on account of differences in temperature between two junctions of dissimilar metals in the same circuit. In this way, a Seebeck device converts temperature differences across a circuit, into electrical energy.

The Seebeck device may comprise an upper plate and a lower plate, wherein the upper plate may be configured to receive heat energy from the sun.

The upper plate may be configured to receive heat energy directly from the sun.

In the case where the electrical generator comprises at least one photovoltaic cell, the solar energy device may further comprise a Seebeck device.

In this case, the Seebeck device may be disposed in between the photovoltaic cell and the thermal transfer element.

The thermal transfer element may comprise at least one heat pipe suitable for transferring at least a portion of incident thermal energy from the sun to a body, in order to elevate the temperature of the body.

The thermal transfer element may comprise a plurality of heat pipes suitable for transferring at least a portion of heat energy from the sun to a body, in order to elevate the temperature of the body.

In accordance with a second aspect of the present invention there is provided a solar energy device comprising a thermal transfer element for transferring at least a portion of heat energy from the sun to a body, wherein the thermal transfer element comprises at least one transfer portion having a first end and a second end and having at least one hollow portion defining a space disposed between said first and second ends, said space being adapted to transfer heat energy between said first and second ends.

At least one said transfer portion comprises at least one heat pipe. The thermal transfer element further comprises a substantially flat plate disposed above at least one said heat pipe and in thermal contact with at least one said heat pipe. Each said heat pipe may have a substantially flat upper surface being in thermal contact with said substantially flat plate.

The thermal transfer element may further comprise a heat conducting elongate hollow member which is in thermal contact with said first end of at least one said transfer portion.

The thermal transfer element may further comprise a heat conducting elongate hollow member, wherein said first end of at least one said transfer portion is disposed inside the heat conducting elongate hollow member.

The thermal transfer element may further comprise a heat conducting lower portion, at least a portion of which is in thermal contact with said substantially flat plate, said lower portion comprising a plurality of profiled channels inside of which said heat pipes are disposed. The transfer portion may comprise a plurality of heat pipes disposed adjacent each other.

The thermal transfer element may further comprise a heat conducting envelope substantially surrounding and in thermal contact with, said plurality of heat pipes.

The transfer portion may comprise a plurality of spaces adapted to transfer heat energy between said first and second ends, said spaces being disposed adjacent each other. The heat conducting elongate hollow member may be a tube. The heat conducting elongate hollow member may be substantially rectangular in cross section.

A BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a perspective view from above and one side of a solar energy device in accordance with a first embodiment of the present invention;

Figure 2 shows an exploded perspective view from above and one side of a solar energy device in accordance with a second embodiment of the present invention;

Figure 3 shows an exploded perspective view from above and one side of a solar energy device in accordance with a third embodiment of the present invention;

Figure 4 shows a perspective view from above and one side of a solar energy device in accordance with a fourth embodiment of the present invention;

Figure 5 shows a perspective view from above and one side of a solar energy device in accordance with a fifth embodiment of the present invention;

Figure 6 shows a perspective view from above and one side of a solar energy device in accordance with a sixth embodiment of the present invention;

Figure 7 shows an exploded perspective view from above and one side of a solar energy device in accordance with a seventh embodiment of the present invention;

Figure 8 shows a perspective view from above and one side of a solar energy device in accordance with an eighth embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

With reference to Figure 1 , a first embodiment of a solar energy device is represented generally by reference numeral 1.

The solar energy device 1 is comprised of a thermal transfer element in the form of a plurality of transfer portions in the form of heat pipes 5 which are substantially surrounded by a heat conducting envelope 7.

It will be clearly understood by a person skilled in the art that a heat pipe is a device for transferring heat energy from one place to another, comprising an elongate hollow element sealed at each end, for example, a sealed tube made from a heat conducting material such as copper or aluminium. A vacuum pump is used to remove air from the space inside the sealed tube, and the space is then filled with a small amount of a coolant such as water or ethanol. Due to the partial vacuum which has been created inside the sealed tube, some of the coolant will be in the liquid state and some of the coolant will be in the gas state. When the temperature of one end (the "hot end") of the sealed tube is elevated, then the gaseous coolant absorbs heat energy and moves along the tube to the other end (the "cold end") of the sealed tube. At the cold end of the sealed tube, the gaseous coolant is condensed back to the liquid state, thereby releasing heat energy at the cold end and elevating the temperature of the cold end. The heat pipe may further comprise a wick disposed in the space inside the sealed tube, in order to assist in the transfer of the condensed coolant back to the hot end.

The heat conducting envelope 7 is comprised of a lower heat conducting portion 7a which includes a plurality of channels such as to surround the major portion of the heat pipes 5, and an upper heat conducting portion which is in the form of a substantially flat plate 7b. In this embodiment, the lower heat conducting portion 7a is made from aluminium and the substantially flat plate 7b is made from aluminium. However, it is to be appreciated that any other suitable material could alternatively be used, for example copper or steel.

The thermal transfer element further comprises a tubular member 8 which is configured so that at least a portion of the first ends of the heat pipes 5 are disposed within the tubular member 8. It is however to be understood that the tubular member 8 could alternatively be made from a heat conducting material and configured so that the heat pipes 5 are in thermal contact with its external wall.

The solar energy panel 1 operates as follows. Heat energy from the sun directly impinges on the substantially flat plate 7b and is transferred to the lower heat conducting portion 7a. As can be clearly seen from Figure 1 , the shape of the lower heat conducting portion 7a (and in particular its good thermal contact with the heat pipes 5) permits the subsequent transfer of heat energy to the heat pipes 5. In this embodiment, an end portion of each of the heat pipes 5 are disposed within the tubular member 8 and in this way, in the event that a fluid such as water for example, is disposed in the interior of the tubular member 8, heat energy is then transferred from the heat pipes 5 to the water, with the result that the temperature of the water is elevated.

Referring now to Figure 2, a second embodiment of a solar energy device is represented generally by reference numeral 101.

The solar energy device 101 is comprised of two main elements. The first element is an electrical generator in the form of a photovoltaic panel 103 comprising a plurality of photovoltaic cells 103a. The second element is a thermal transfer element such as that described with reference to Figure 1, and comprises a plurality of heat pipes 105, a heat conducting envelope 107 and a tubular member 108. As can be clearly seen from Figure 2, the second element is disposed underneath and in physical contact with the first element in use. Moreover, the heat conducting envelope 107 and hence the heat pipes 05, are in thermal contact with the photovoltaic panel 103.

The solar energy device 101 operates as follows. Light energy from the sun impinges on the photovoltaic pane! 03 and as a result, the light energy is converted into electrical energy which is either stored in an external storage device such as a battery (not shown) to be utilised as required, or transferred to the national electricity network for example. The energy conversion efficiency of a photovoltaic panel is reduced in the event that heat energy is not adequately dissipated. Conversely, if heat energy is adequately dissipated from a photovoltaic panel then the energy conversion efficiency is significantly improved.

Turning now to the role of the second element, the heat energy from the sun which has directly impinged on the photovoltaic panel 103 is transferred to the heat pipes 105 via the heat conducting envelope 107. At least a portion of the heat energy is then transferred from the heat pipes 05 to a body of water which is disposed in the tubular member 108. As a result, the temperature of the body of water inside the tubular member 108 is elevated.

It will be understood by a person skilled in the art that the purpose of the thermal transfer element is two fold: - (i) to help to dissipate heat from the photovoltaic panel 103 in order to improve its energy conversion efficiency; and (ii) to elevate the temperature of a body of water, which can be used in any circumstances, whether domestic or commercial, when it is desired to elevate the temperature of water, for example, in a central heating system.

Referring now to Figure 3, a third embodiment of a solar energy device is represented generally by reference numeral 201.

In this embodiment, the solar energy device 201 is also comprised of two main elements. Although this embodiment also comprises a second element in the form of a thermal transfer element comprising a plurality of heat pipes 205, a heat conducting envelope 207 and a tubular member 208 identical to that of the first embodiment, the first element is, in this embodiment, a Seebeck device 204 as opposed to a photovoltaic panel. The Seebeck device 204 is comprised of an upper plate 204a and a lower plate 204b which are in physical contact with each other. In the event that heat energy impinges on the upper plate 204a, the temperature of the upper plate 204a is elevated. In the event that the temperature of the lower plate 204b is simultaneously decreased, then the heat energy impinging on the device 204 is converted into electrical energy which is either stored in an external storage device such as a battery (not shown) and then utilised as required, or transferred to the national electricity network for example.

As can be clearly seen from Figure 3, the Seebeck device 204 is disposed directly above the thermal transfer element in use, and is in thermal contact with the thermal transfer element, in particular the heat conducting envelope 207.

The solar energy device 201 operates as follows. Heat energy from the sun directly impinges on the upper plate 204a of the Seebeck device 204 which elevates the temperature of the upper plate 204a. Moreover, the presence of the thermal transfer element in physical contact with the lower plate 204b of the Seebeck device decreases the temperature of the lower plate 204b, with the result that electrical energy is generated in the Seebeck device, which is either stored in an external storage device such as a battery (not shown) and then utilised as required, or transferred to the national electricity network for example.

At least a portion of the heat energy from the sun which has been transferred from the lower plate 204b of the Seebeck device to the heat pipes 205 is then transferred to a body of water which is disposed in the tubular member 208. As a result, the temperature of the body of water inside the tubular member 208 is elevated.

It will be understood by a person skilled in the art that the purpose of the thermal transfer element is two fold: - (i) to decrease the temperature of the lower plate 204b of the Seebeck device 204 in order to create a temperature differential across the Seebeck device 204 in order to generate electrical energy; and (ii) to elevate the temperature of a body of water, which can be used in any circumstances, whether domestic or commercial, when it is desired to elevate the temperature of water, for example, in a central heating system.

Referring now to Figure 4, a fourth embodiment of a solar energy device is represented generally by reference numeral 301.

In this embodiment, the solar energy device 301 is comprised of three main elements, in particular, a first element in the form of a photovoltaic panel 303 similar to that included in the second embodiment, a second element in the form of a Seebeck device 304 similar to that included in the third embodiment, and a third element in the form of a plurality of heat pipes 305, a heat conducting envelope 307 and a tubular member 308 similar to that included in the first embodiment.

As can be clearly seen from Figure 4, the photovoltaic panel 303 is disposed directly above the Seebeck device 304 in use, and is in thermal contact with the Seebeck device 304. Moreover, the Seebeck device 304 is disposed directly above the heat transfer element in use, and is in thermal contact with the heat transfer element. The solar energy device 301 operates as follows. Light energy from the sun directly impinges on the photovoltaic panel 303, with the result that electrical energy is generated and either stored in an external storage device such as a battery (not shown) and then utilised as required or transferred to the national electricity network for example.

The heat energy from the sun passes through the photovoltaic panel 303 and impinges on the Seebeck device 304, with the result that the temperature of the upper plate 304a is increased. The presence of the thermal transfer element in physical contact with the lower plate 304b of the Seebeck device 304 decreases the temperature of the lower plate 304b, and this in conjunction with the elevation of the temperature of the upper plate 304a results in the generation of electrical energy which is either: - (a) stored in the same external storage device as that described with reference to the photovoltaic panel; (b) stored in a further external storage device (not shown); or (c) transferred to the national electricity network for example.

At least a portion of the heat energy from the sun is transferred from the lower plate 304b of the Seebeck device to the heat pipes 305 and is then transferred to a body of water which is disposed in the tubular member 308. As a result, the temperature of the body of water is elevated.

It will be understood by a person skilled in the art that the purpose of the thermal transfer element is three fold: - (i) to decrease the temperature of the lower plate 304b of the Seebeck device 304 in order to create a temperature differential across the Seebeck device 304 to generate electrical energy; (ii) to elevate the temperature of a body of water, which can be used in any circumstances, whether domestic or commercial, when it is desired to elevate the temperature of water, for example, in a central heating system; and (iii) to help to dissipate heat from the photovoltaic panel 303 in order to improve its energy conversion efficiency.

Referring now to Figure 5, a fifth embodiment of a solar energy device is represented generally by reference numeral 401.

The solar energy device 401 is similar to the embodiment of Figure 1 and comprises a thermal transfer element in the form of a plurality of transfer portions in the form of heat pipes 405 which are substantially surrounded by a heat conducting envelope 407. The thermal transfer element further comprises a tubular member 408 which is configured so that at least a portion of the heat pipes 405 are either disposed within the tubular member 408 or in thermal contact with its outer wall.

However, the solar energy device 401 differs from the embodiment of Figure 1 in that the heat conducting envelope 407 is a one piece envelope substantially surrounding the major portion of the heat pipes 405.

Referring now to Figure 6, a sixth embodiment of a solar energy device is represented generally by reference numeral 50 .

The solar energy device 501 is similar to the embodiment of Figure 1 and comprises a thermal transfer element in the form of a plurality of transfer portions in the form of heat pipes 505a which are in thermal contact with a heat conducting portion 507. The thermal transfer element further comprises a tubular member (not shown) similar to that shown in Figure 1, which is configured so that at least a portion of the heat pipes 505 are either disposed within the tubular member or in thermal contact with its outer wall.

However, the solar energy device 501 differs from the embodiment of Figure 1 in that the heat pipes 505a are profiled to have a D-shaped cross- section; that is, each heat pipe 505a has a substantially flat upper profile.

Moreover, the thermal transfer element does not comprise a heat conducting envelope which surrounds the heat pipes 505a, and instead, it comprises only a substantially flat plate 507b, similar to the substantially flat plate 7b of Figure . The substantially flat upper profile of the heat pipes 505a ensures good thermal contact of the heat pipes 505a with the substantially flat plate 507b.

It is also to be appreciated that as an alternative to the heat pipes having a shape such that they are D-shaped in cross section, the heat pipes 505b could alternatively be ovoid in shape, which also provides a substantially flat upper profile to ensure good thermal contact with the substantially flat plate 507b.

Referring now to Figure 7, a seventh embodiment of a solar energy device is represented generally by reference numeral 601.

The solar energy device 601 comprises a thermal transfer element in the form of a transfer portion comprising a plurality of hollow portions 621 each defining a space 623 disposed between the first end 625 and the second end 627 of the transfer portion. The spaces 623 are each adapted to transfer heat energy between the first 625 and second 627 ends. For example, the spaces 623 are partially evacuated and contain coolant and a wick, effectively functioning as heat pipes. The thermal transfer element further comprises a heat conducting elongate hollow element 629, which is substantially rectangular in cross section. The heat conducting elongate hollow member 629 is configured so that the first end 625 of the transfer portion is in thermal contact with the external wall of the heat conducting elongate hollow element 629.

The feature of the heat conducting elongate hollow element 629 being substantially rectangular in cross section ensures that it can abut against the first end 625 of the transfer portion in order to ensure good thermal contact between the first end 625 and the heat conducting elongate hollow element 629, so that in the event that water is passing through the heat conducting elongate hollow element 629, heat energy is efficiently transferred to it

It is also to be appreciated that the heat conducting elongate hollow element 629 could be integrated with the transfer portion in order to provide a one-piece thermal transfer element.

Referring now to Figure 8, an eighth embodiment of a solar energy device is represented generally by reference numeral 701.

The solar energy device 701 comprises a thermal transfer element in the form of a transfer portion comprising a hollow portion 731 defining a space 733 disposed between the first end 725 and the second end 727 of the transfer portion. The space 733 is adapted to transfer heat energy between the first 725 and the second 727 ends in a similar fashion to the space 623 of the embodiment of Figure 7.

The substantially flat nature of the space 733 ensures good transfer of heat energy into the space 733. The thermal transfer element further comprises a heat conducting elongate hollow member 729 which is identical to that described with reference to Figure 7.

It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only, and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims.

Claims

What I claim is:

1. A sotar energy device comprising:

2. A solar energy device as claimed in claim 1, wherein the electrical generator comprises at least one photovoltaic cell for converting at least a portion of light energy from the sun into electrical energy. 3. A solar energy device as claimed in claim 1, wherein the electrical generator comprises at least one thermoelectric generator for converting at least a portion of heat energy from the sun into electrical energy.

4. A solar energy device as claimed in any one of the previous claims, wherein the thermoelectric generator comprises a Seebeck device.

5. A solar energy device as claimed in claim 2, wherein the solar energy device further comprises a Seebeck device.

6. A solar energy device as claimed in claim 5, wherein the Seebeck device is disposed in between the photovoltaic cell and the thermal transfer element. 7. A solar energy device as claimed in any one of the previous claims, wherein the thermal transfer element comprises at least one heat pipe suitable for transferring at least a portion of incident thermal energy from the sun to a body, in order to elevate the temperature of the body. 8. A solar energy device as claimed in any one of the previous claims, wherein the thermal transfer element comprises a plurality of heat pipes suitable for transferring at least a portion of heat energy from the sun to a body, in order to elevate the temperature of the body. 9. A solar energy device comprising a thermal transfer element for transferring at least a portion of heat energy from the sun to a body, wherein the thermal transfer element comprises at least one transfer portion having a first end and a second end and having at least one hollow portion defining a space disposed between sid first and second ends, said space being adapted to transfer heat energy between said first and second ends.

10. A solar energy device as claimed in claim 9, wherein at least one said transfer portion comprises at least one heat pipe.

11. A solar energy device as claimed in claim 10, wherein the thermal transfer element further comprises a substantially flat plate disposed above at least one said heat pipe and in thermal contact with at least one said heat pipe. 2. A solar energy device as claimed in claim 11 , wherein each said heat pipe has a substantially flat upper surface being in thermal contact with said substantially flat plate. 13. A solar energy device as claimed in any one of claims 9 to 12, wherein the thermal transfer element further comprises a heat conducting elongate hollow member which is in thermal contact with said first end of at least one said transfer portion. 14. A solar energy device as claimed in any one of claims 9 to 12, wherein the thermal transfer element further comprises a heat conducting elongate hollow member, wherein said first end of at least one said transfer portion is disposed inside the heat conducting elongate hollow member. 15. A solar energy device as claimed in any one of claims 11 to 14, wherein the thermal transfer element further comprises a heat conducting lower portion, at least a portion of which is in thermal contact with said substantially flat plate, said lower portion comprising a plurality of profiled channels inside of which said heat pipes are disposed.

16. A solar energy device as claimed in any one of claims 9 to 15, wherein said transfer portion comprises a plurality of heat pipes disposed adjacent each other.

17. A solar energy device as claimed in claim 16, wherein the thermal transfer element further comprises a heat conducting envelope substantially surrounding and in thermal contact with, said plurality of heat pipes.

18. A solar energy device as claimed in any one of claims 9 to 15, wherein the transfer portion comprises a plurality of spaces adapted to transfer heat energy between said first and second ends, said spaces being disposed adjacent each other.

19. A solar energy device as claimed in any one of claims 13 to 18, wherein said heat conducting elongate hollow member is a tube.

20. A solar energy device as claimed in any one of claims 13 to 18, wherein said heat conducting elongate hollow member is substantially rectangular in cross section.