DEVICE FOR GENERATING ELECTRICITY

Abstract

The present disclosure provides a device for generating electricity. The device comprises a panel having an area that is transparent for at least a portion of visible light and having a light receiving surface. The panel comprises at least one series of solar cells, each solar cell having opposite major surfaces having opposite electrical polarities, each solar cell overlapping another one of the solar cells and being electrically connected in series. The at least one series of solar cells is positioned along and in the proximity of an edge of the panel, along the area that is transparent for at least a portion of visible light and substantially parallel the light receiving surface of the panel.

Claims

1. A device for generating electricity, the device comprising: a panel having an area that is transparent for at least a portion of visible light and having a light receiving surface; and at least one series of solar cells, each solar cell having opposite major surfaces having opposite electrical polarities, each solar cell overlapping another one of the solar cells therein and being electrically connected in series; wherein the at least one series of solar cells is positioned along and in the proximity of an edge of the panel, along the area that is transparent for at least a portion of visible light and substantially parallel the light receiving surface of the panel.

2. (canceled)

3. The device of claim 1 wherein the device is provided in the form of a window unit.

4. The device of claim 1 wherein the solar cells of the at least one series of solar cells are positioned in a shingle-like arrangement.

5. The device of claim 1 wherein solar cells of the at least one series of solar cells are bonded to the panel in a manner such that an airgap between the solar cells and the panel is avoided.

6. The device of claim 5 wherein the solar cells of the at least one series of solar cells comprise an outer layer of a polymeric material and are directly bonded to the panel.

7. (canceled)

8. The device of claim 1 wherein the at least one series of solar cells is one of a plurality of series of solar cells which are positioned around the area that is transparent for at least a portion of visible light and in the proximity of edges of the panel such that the panel is largely transparent for at least a portion of visible light the area that is transparent for at least a portion of visible light is a central area and at 10 times larger than an area of the panel at which the series of the solar cells are positioned.

9. The device of claim 1 wherein the at least one series of solar cells is one of at least two series of solar cells positioned along adjacent edges of the panel.

10. The device of claim 9 wherein adjacent ones of the at least two series of the solar cells are oriented at an angle relative to each other and substantially parallel to the light receiving surface of the panel and wherein at least one solar cell of the at least two series of solar cells overlaps with at least one solar cell of an adjacent one of the at least two series of solar cells.

11. (canceled)

12. The device of claim 9 wherein the at least one solar cell of the at least two series of solar cells overlaps with at least one solar cell of an adjacent one of the at least two series of solar cells and are electrically connected whereby the at least two series of solar cells are electrically series connected.

13. The device of claim 9 wherein the at least one solar cell of the at least two series of solar cells overlaps with, and is electrically insulated from, at least one solar cell of an adjacent one of the at least two series of solar cells and the at least two series of solar cells are electrically connected in parallel.

14. The device of any one of claim 9 wherein a solar cell positioned at an end of one of the at least two series of solar cells overlaps a solar cell of the adjacent one of the at least two series of solar cells in a manner such that the adjacent series of solar cells form an angle.

15. The device of claim 9 wherein adjacent ones of the at least two series of the solar cells are substantially parallel to each other and face the light receiving surface.

16. The device of claim 15 wherein at least one solar cell of the at least two series of solar cells overlaps with at least one solar cell of an adjacent one of the at least two series of solar cells.

17. The device of claim 9 wherein a first and a second series of the solar cells are positioned immediately adjacent each other and all or at least most of the solar cells of the first series overlap with respective solar cells of the second series of solar cells.

18. The device of claim 17 wherein the solar cells of the first series are electrically connected with respective ones of the solar cells of the second series and the solar cells of the second series are electrically series connected.

19. The device of claim 9 wherein the first and second series of solar cells are electrically insulated from each other and the solar cells of the first series are series connected and the solar cells of the second series are electrically series connected.

20. The device of claim 9 wherein the solar cells of the first and second series are inclined in the same manner and direction.

21. The device of claim 9 wherein the solar cells of the first and second series are inclined in a opposite manner and direction.

22. The device of claim 9 wherein the solar cells of the first and second series are inclined by different angles relative to a surface normal of the receiving surface.

23. (canceled)

24. The device of claim 1 wherein the panel is a first panel and the device comprises a second panel that is positioned substantially parallel the first panel in a manner such that light received by the light receiving surface of the first panel initially propagates through the first panel before being received by the second panel, wherein the second panel has an area that is transparent for at least a portion of visible light.

25-37. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 is a schematic top view of a device for generating electricity in accordance with an embodiment of the present invention;

[0036] FIG. 2 is a schematic cross-sectional representation of a component of the device for generating electricity in accordance with an embodiment of the present invention;

[0037] FIG. 3 is a schematic top view of a portion of the device for generating electricity shown in FIG. 1; and

[0038] FIGS. 4 and 5 are schematic cross-sectional representations of a portion of the device in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0039] Referring initially to FIG. 1, there is shown a schematic top view of a device for generating electricity 100 in accordance with an embodiment of the present invention. The device 100 comprises a panel 102 and in this embodiment four series of solar cells 104 106, 108,110 are positioned at respective edges of the panel 102. The four series of solar cells 104 106, 108,110 face a light receiving surface of the panel and together surround an area of the panel that is at least largely transmissive for light. The panel 102 may for example form a panel of a window of a building or another structure and the four series of solar cells 104 106, 108,110 may be positioned at a frame structure that supports the panel 102 and one or more other panels to for a window unit.

[0040] The panel 102 may have any shape, but in one specific embodiment is rectangular and may be square. The panel 102 may be formed from suitable glass or polymeric materials.

[0041] FIG. 2 shows a cross-sectional representation of a portion of the panel 102 and a portion of the series of solar cells 108. The solar cells 112 of the series of solar cells 108 and arranged in an overlapping relationship and electrically coupled using a conductive adhesive 116. The solar cells 112, have opposite major surfaces and which have different polarities and are oriented such that only surfaces of the same polarities face the panel 102. The conductive adhesive 116 couples a back face of one of the solar cells 112 with a front face of an adjacent solar cell 112. Consequently, the solar cells of the series of solar cells are electrically series connected.

[0042] The solar cells 112 are adhered directly to the panel 102. In this example the solar cells 112 comprise outer ETA layers. Prior to adhering the solar cells 112 to the panel 102, the ETA is slightly softened (by the careful application of heat) and then the solar cells 112 are pressed against the panel 102. Once the softened ETA has hardened again, the solar cells are adhered to the panel 102.

[0043] FIG. 2 is a schematic representation only. A person skilled in the art will understand that the solar cells 112 relatively long compares to their thickness and consequently the solar cells 112 are substantially parallel the panel 102 even though they are arranged in an overlapping (shingled) relationship.

[0044] Turning now to FIG. 3, there is shown a schematic representation of a corner region of the of the device shown in FIG. 1. FIG. 3 shows a portion of the panel 102 and a portion of adjacent series of solar cells 108, 110. In this embodiment the series of the solar cells 108, 110 form a right angle and an end surface of a solar cell positioned at end of the series 110 of solar cells overlaps with a side portion of a solar cell positioned at an end of the other series 108 of solar cells. The overlapping portions of the solar cells are electrically series connected using a conductive adhesive 116 in the same manner as illustrated above with reference to FIG. 2. In a variation of the described embodiment the overlapping portions of the solar cells at the ends of the series 108, 110 are electrically insulated from each other and the series of solar cells 108, 110 are electrically parallel connected.

[0045] Turning now to FIG. 4, there is shown a cross-sectional view of a portion of a window unit in accordance with an embodiment of the present invention. The window unit 400 comprises the panel 102 with the series of (shingled) solar first cells 104, 106, 108 and 110, which are encapsulated by a layer of ETA 109. The panel 102 has a light receiving surface 103. In this embodiment the panel 102 is a first panel and the window unit 400 also comprises a second panel 402, which is positioned parallel, and spaced apart from, the first panel 102. The second panel 402 has series of solar cells 404 directly adhered to it in the same manner as illustrated above for the first panel 102 and with reference to FIGS. 1, 2 and 3. In this embodiment the panels 102 and 402 are rectangular and each comprise four series of solar cells that are adhered at edge portions of the panels 102, 404 and positioned as illustrated in FIG. 1. The series of solar cells comprise overlapping (shingled) solar cells as illustrated in FIG. 2 and corners are formed in a manner as illustrated above in FIG. 3 for the first panel 102.

[0046] The window unit 400 also comprises a frame structure 405 that is arranged to hold the panels 102 and 402 and the series of solar cells in position.

[0047] The panels 102 and 404 comprise in this embodiment respective panes of glass that are each largely transmissive for visible light. In an embodiment the glass panes that form the panels 102 and 404 are formed of low iron ultra-clear glass pane, with the panel 404 additionally having a low-E coating.

[0048] In the embodiment shown in FIG. 4 the panel 404 is a laminate structure having three sub-panes 404a, 404b and 404c. The sub-pane 404a is formed of low iron ultra-clear glass having a thickness of 4 mm, and second and third panes 404b and 404c are each formed from ultra-clear glass having a thickness of 4 mm. The sub-panes 404a, 404b and 404c mate with each other to form a stack of the sub-panes substantially parallel to one another. Disbursed between panes 404a and 404b is an interlayer 410 of polyvinyl butyral (PVB). A PVB interlayer 412 is also located between sub-pane 404b and 404c, but PVB interlayer 412 also includes a light scattering element. In this embodiment the light scattering element comprises a luminescent scattering powder embedded in the PVB, which also an epoxy that provides adhesive. The panel 404 also includes a diffraction grating that is arranged to facilitate redirection of light towards edge region of the panel 404 (i.e. towards the frame 20) and guiding of the light by total internal reflection.

[0049] It should be appreciated that the panel 404 could have any number of panes with any number of interlayers. In some embodiments the panel 404 may comprise a single piece of optically transmissive material such as glass.

[0050] The panel 404 has an edge 411 that has a plane which is transverse to the light receiving surface 103. In the embodiment of FIG. 2, the angle between the edge 411 and the light receiving surface 103 is 90°.

[0051] The window unit 400 also has series of third solar cells 414. The series of third solar cells 414 face the edge 411 and a cavity between the first panel 102 and the second panel 404. The series of third solar cells 414 substantially surround the second panel 404 and are positioned to receive light that is redirected by the scattering material and/or the diffractive element (not shown) to the edges 416 of the second panel 404. Further, the series of third solar cells 414 also receives light at an area which faces the cavity between the first panel 102 and the second panel 404.

[0052] FIG. 5 shows a device for generating electricity in accordance with a further embodiment of the present invention. FIG. 5 shows the device 500 having a first panel 502 and a second panel 504. The first and second panels 502, 504 are transmissive for at least 70% of incident visible light (limited by the transmissivity of the panel material, such as glass). The device 500 comprises the above-described series of solar cells 104 106, 108, 110 (only the series 104 is shown in FIG. 5) positioned at respective edges of the panels 502, 504.

[0053] The solar cells 104 106, 108, 110 each have light receiving surface portions facing the panel 502 and adhered to the panel 502 such that no air gap is present between the solar cells 104, 106, 108, 110 and the panel 502. Further, the solar cells 104, 106, 108, 110 each have a rear surface portions facing the panel 504 and adhered to the panel 504. In this example the solar cells 104, 106, 108, 110 comprise outer polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA) layers at the front surfaces. A sheet of excluded-volume-branched-polymers (EVB) or Ethylene tetrafluoroethylene (ETFE) is placed between the panels 502 and 504 such that the sheet is also positioned between the rear surfaces of the solar cells 104, 106, 108, 110 and panel 504. Prior to adhering the solar cells 104, 106, 108, 110 to the panels 502, 504 (and the panels 502, 504 to each other) the PVB, ETA, EVB or ETFE is slightly softened (by the careful application of heat) and then the panel 502, 504 are pressed together such that the solar cells 104, 106, 108, 110 are positioned between the panels 502, 504. Once the softened PVB, ETA, EVB or ETFE has hardened again, the solar cells are sandwiched between, and adhered to, the panels 502, 504 without the need of an additional adhesive whereby a laminated structure is formed. The panels 502, 504 protect the solar cells 104, 106, 108, 110 and also provide reliable sealing surfaces at both front and rear sides of the device, which is advantageous for window applications.

[0054] In the present embodiment, the series of first and second solar cells 104, 106, 108, 110, 408 may be silicon-based solar cells, but can alternatively also be based on any other suitable material such CdS, CdTe, GaAs, CIS or CIGS. The series of third solar cells 414 may be CIS or CIGS-based, but may alternatively also be based on any other suitable material such SI, CdS, CdTe, or GaAs.

[0055] Whilst a number of specific embodiments have been described, it should be appreciated that the disclosed unit 400 maybe embodied in many other forms. For example, the unit 400 may not necessarily be rectangular, but may alternatively have any other suitable shape (such as for example round or rounded). Further, the panel 404 may comprise any suitable number of sub-panels. Further, the window unit may comprise a third panel such that a triple glazing unit is formed.

[0056] Any discussion of the background art throughout this specification should in no way be considered as an admission that such background art is prior art, nor that such background art is widely known or forms part of the common general knowledge in the field in Australia or worldwide.

[0057] Further, a person skilled in the art will appreciate that modifications of the described embodiments are possible. For example, the solar cells within each series may not necessarily be series connected. The device may also comprise adjacent and substantially parallel series of solar cells. The adjacent and substantially parallel series of solar cells may overlap such that each solar cell of a first series overlaps with a (or a respective) solar cell an immediate adjacent and substantially parallel series of the solar cells. The solar cells of a first series may be electrically series connected or alternatively may be electrically isolated from each other and electrically connected with the respective solar cells of a second series. For example, the solar cells of the first series may be electrically connected with respective ones of the solar cells of the second series and the solar cells of the second series are electrically series connected. The solar cells of the first and second series may be inclined in the same manner and direction. Alternatively, the solar cells of the first and second series may be inclined in a opposite manner and direction. Further, the solar cells of the first and second series may be inclined by the same or different angles relative to a surface normal of the receiving surface.