Power generation device

Abstract

The present disclosure provides a power generating device. The device includes a panel having a light-receiving surface with an area transparent to at least a portion of visible light. The panel includes at least one string of solar cells, each solar cell having a pair of opposing major surfaces with opposite electrical polarity, each solar cell overlapping and electrically connected in series with another solar cell. The at least one string of solar cells is arranged along and adjacent to an edge of the panel, and is arranged along the area transparent to at least a portion of visible light and substantially parallel to the light-receiving surface of the panel.

Description

Technical Field

[0001] The present disclosure relates to a power generation device, and more particularly, but not limited thereto, to a panel such as a window panel including a solar cell.

Background Art

[0002] Buildings such as office towers, high-rise residences, and hotels use a large number of external window panels and / or facades incorporating glass panels.

[0003] Overheating of an internal space such as a space receiving sunlight through such a window panel is a problem that can be overcome by using an air conditioner. A large amount of energy is globally used for the operation of air conditioners.

[0004] PCT International Application Numbers PCT / AU2012 / 000778, PCT / AU2012 / 000787, and PCT / AU2014 / 000814 (owned by the present applicant) disclose a spectral selectivity panel that can be used as window glass, transmits most of the visible light, but deflects a part of the incident infrared light to the side of the panel, where it is absorbed by a solar cell to generate electricity.

[0005] It should be understood that when a prior art publication is referred to in this specification, such reference does not admit that the publication forms part of the common general knowledge in the art in Australia or any other country.

Summary of the Invention

[0006] In a first aspect, the present invention provides a power generation device, which includes a panel having a region transparent to at least a part of visible light and having a light-receiving surface, and at least one solar cell string, wherein each solar cell has a pair of main surfaces having opposite electrical polarities and facing each other, and each solar cell overlaps with one of the other solar cells in the solar cell string and is electrically connected in series. The at least one solar cell string is arranged along and in proximity to an end of the panel, and is arranged along a region transparent to at least a part of visible light and substantially parallel to the light-receiving surface of the panel.

[0007] The panel may be a window panel, and the device may further include a frame structure for supporting the panel. In this embodiment, the device may be provided in the form of a window unit for a building, such as an insulating glass unit.

[0008] The plurality of solar cells in the solar cell string are arranged in an overlapping relationship with each other or in a shingle-like arrangement, which has advantages for window applications. In such applications, space is limited and the solar cells need to be made as small as possible. Embodiments of the present invention prevent gaps from forming between adjacent solar cells. As a result, the conversion efficiency per unit area can be improved. Further, top contacts or fingers for reducing the area of each solar cell available for receiving photons for power generation are not required.

[0009] The plurality of solar cells of at least one solar cell string may have a front surface that is directly or indirectly joined to the panel so that no gap is created between the plurality of solar cells and the panel. An additional adhesive may be used for the joining. In one embodiment, the adhesive has a refractive index approximating at least that of the panel material and may be, for example, glass or a suitable polymeric material. Alternatively, the solar cell may have an outer layer of a polymeric material such as polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA) or another suitable material. The solar cell is directly joined to the panel in this embodiment. For example, if the solar cell includes a layer of PVB or EVA or other suitable material, the material may be softened slightly and then adhered directly to the panel. Since no gap is created between the panel and the solar cell, the intensity loss of light propagating from the panel into the solar cell is reduced.

[0010] The device may comprise a plurality of solar cell strings, and the plurality of solar cell strings may be arranged around (and may surround) a region that is transparent to at least a portion of visible light. The plurality of solar cell strings may be arranged adjacent to an end of the panel such that the panel is largely transparent to at least a portion of visible light, the region that is transparent to at least a portion of visible light is a central region, and the area of the panel where the solar cell strings are arranged is 5 times, 10 times, 15 times, 20 times, 50 times, 100 times, or 500 times larger.

[0011] At least one solar cell string is typically arranged on a panel surface facing the light-receiving surface such that light received by the light-receiving surface propagates through at least a portion of the panel before reaching the at least one solar cell string.

[0012] The panel may have four ends, and at least one of the solar cell strings may be arranged at each end of the panel.

[0013] In one particular embodiment, at least one solar cell row includes at least two solar cell rows that are disposed at adjacent ends of the panel and may be electrically connected in series or in parallel.

[0014] In one embodiment, adjacent solar cell rows among at least two solar cell rows may be oriented at an angle with respect to each other (for example, an angle within the range of 80 to 100 degrees, or an angle of substantially 90 degrees), and may face the light-receiving surface. At least one solar cell in at least two solar cell rows may overlap with at least one solar cell in adjacent solar cell rows among at least two solar cell rows, whereby at least two solar cell rows may be electrically connected in series. Alternatively, at least one solar cell in at least two solar cell rows may overlap with at least one solar cell in adjacent solar cell rows among at least two solar cell rows and may be electrically insulated, and at least two solar cell rows may be electrically connected in parallel.

[0015] In one specific example, a solar cell disposed at an end of one of at least two solar cell rows overlaps with at least one solar cell in an adjacent solar cell row among at least two solar cell rows in such a way that the adjacent pair of solar cell rows form an angle.

[0016] In one particular embodiment, the panel has a substantially rectangular shape with substantially right angles. An adjacent pair of solar cell rows may be disposed at adjacent ends of the panel such that the adjacent pair of solar cell rows form substantially right angles. In this embodiment, one solar cell disposed at the end of an adjacent solar cell row can form an overlapping relationship with the side surface of one solar cell disposed at the end of the adjacent solar cell row.

[0017] In one embodiment, adjacent solar cell pairs among at least two solar cell rows are substantially parallel to each other and face the light-receiving surface. At least one solar cell in at least two solar cell rows may overlap with at least one solar cell in adjacent solar cell rows among at least two solar cell rows, and may or may not be electrically connected in series. Further, the first solar cell row and the second solar cell row may be arranged directly adjacent to each other (and substantially parallel), and all or at least most of the plurality of solar cells in the first solar cell row may overlap with each of the plurality of solar cells in the second solar cell row. Some or all of the plurality of solar cells in the first solar cell row may be electrically insulated from or electrically connected to each of the solar cells in the second solar cell row. In one specific embodiment, the plurality of solar cells in the first solar cell row are electrically connected to each of the plurality of solar cells in the second solar cell row, and the plurality of solar cells in the second solar cell row are electrically connected in series. Alternatively, the first solar cell row and the second solar cell row may be electrically insulated from each other, the plurality of solar cells in the first solar cell row may be connected in series, and the plurality of solar cells in the second solar cell row may be electrically connected in series.

[0018] The plurality of solar cells in the first solar cell row and the plurality of solar cells in the second solar cell row may be inclined in the same manner and direction. Alternatively, the plurality of solar cells in the first solar cell row and the plurality of solar cells in the second solar cell row may be inclined in opposite manners and directions. Further, the plurality of solar cells in the first solar cell row and the plurality of solar cells in the second solar cell row may be inclined at the same angle or different angles with respect to the surface normal of the light-receiving surface.

[0019] The panel may be a first panel, and the device may include a second panel. The second panel may be arranged substantially parallel to the first panel in such a way that the light received by the light-receiving surface of the first panel first propagates through the first panel before being received by the second panel. The second panel may have a region that is transparent to at least a part of the visible light.

[0020] Each solar cell may have a back surface that is directly or indirectly coupled to the second panel, whereby each solar cell within the first solar cell column and / or within the second solar cell column may be directly or indirectly joined to both the first panel and the second panel and may be sandwiched between the first panel and the second panel. In this embodiment, both the front and back surfaces of the device are surfaces of the first panel or the second panel (which may be a glass panel), which has the advantage of protecting the solar cells and also has the advantage of providing a reliable (vacuum) seal surface for window applications.

[0021] At least one solar cell column may be at least one of the cell columns of the first solar cells, and the device may further include at least one cell column of the second solar cells arranged on the second panel. Each second solar cell may have a pair of main surfaces facing each other with opposite electrical polarities, and each second solar cell may overlap with another one of the plurality of second solar cells and may or may not be electrically connected in series, where at least one of the cell columns of the second solar cells is arranged along and in the vicinity of an end of the second panel and faces the light-receiving surface of the first panel.

[0022] The second solar cell may be joined to the second panel so that no gap is created between the second solar cell and the second panel.

[0023] The second panel may have four ends and may include at least one cell column of the second solar cells arranged at each end of the second panel.

[0024] In one specific embodiment, at least one of the cell rows of the second solar cell includes a plurality of cell rows of second solar cells oriented at adjacent ends of the second panel. The plurality of cell rows of the second solar cell may be oriented at an angle with respect to each other (for example, an angle within the range of 80 to 100 degrees, or an angle substantially of 90 degrees). At least one of the second solar cells of at least one cell row of one second solar cell may overlap with at least one of the second solar cells of the cell row of the adjacent second solar cell. In one specific example, at least one of the second solar cells disposed at the end of the cell row of one second solar cell may overlap with at least one of the second solar cells of the cell row of the adjacent second solar cell such that the adjacent pair of solar cell rows form an angle. The solar cells overlapping at the ends of the cell rows of the adjacent second solar cells may be electrically connected to each other, whereby the adjacent solar cell rows are electrically connected in series. Alternatively, the solar cells overlapping at the ends of the cell rows of the adjacent second solar cells may be electrically insulated from each other, and the adjacent solar cell rows may be electrically connected in parallel.

[0025] In one particular embodiment, the second panel has a substantially rectangular shape with substantially right angles. At least two of the cell rows of the second solar cell may be disposed at adjacent ends of the second panel such that the adjacent solar cell rows form substantially right angles. In this embodiment, the second solar cell disposed at one end of the cell row of one second solar cell may overlap with the side surface of the second solar cell disposed at the end of the cell row of the adjacent second solar cell.

[0026] The second panel may further include a diffraction element and / or a luminescent material to facilitate the reorientation of the incident infrared light to the ends of the second panel.

[0027] Furthermore, the device may include at least one cell row of third solar cells disposed on at least one end surface of the second panel and oriented substantially perpendicular to the main surface of the second panel, whereby at least one cell row of the third solar cells can be disposed substantially perpendicular to the cell row of the first solar cells in the first panel and the cell row of the second solar cells in the second panel. The cell row of the third solar cells is arranged to receive at least a part of the light whose direction has been changed by the diffraction element and / or the luminescent material. The deflection of the infrared radiation by the diffraction element can reduce the transmission of infrared radiation into the building (when the panel is used as window glass), and as a result, it has the further advantage of reducing the overheating of the space inside the building and reducing the air conditioning cost.

[0028] The solar cells may be silicon-based solar cells, but alternatively may be based on any other suitable materials such as CIGS or CIS, GaAs, CdS or CdTe.

[0029] In one specific embodiment, the first solar cells and the second solar cells are silicon-based solar cells, and the third solar cells are CIS-based or CIGS-based solar cells.

[0030] The present invention will be more fully understood from the following description of specific embodiments of the present invention. Hereinafter, it will be described with reference to the drawings.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0032] First, referring to FIG. 1, a schematic top view of a power generation device 100 according to an embodiment of the present invention is shown. The power generation device 100 includes a panel 102. In this embodiment, four solar cell rows 104, 106, 108, and 110 are arranged at respective ends of the panel 102. The four solar cell rows 104, 106, 108, and 110 face the light-receiving surface of the panel and together surround a region of the panel that is at least mostly light-transmissive. The panel 102 may form, for example, a window panel of a building or another structure, and the four solar cell rows 104, 106, 108, and 110 may be arranged in a frame structure that supports the panel 102 and one or more other panels for a window unit.

[0033] The panel 102 can have any shape, but in one particular embodiment, it is rectangular and may be square. The panel 102 may be formed from a suitable glass or polymer material.

[0034] FIG. 2 is a cross-sectional view of a part of the panel 102 and a part of the solar cell row 108. A plurality of solar cells 112 in the solar cell row 108 are arranged in an overlapping relationship and are electrically connected using a conductive adhesive 116. The solar cells 112 have a pair of opposing main surfaces, and the pair of main surfaces have different polarities and are oriented such that only the main surfaces of the same polarity face the panel 102. The conductive adhesive 116 couples the back surface of one solar cell 112 to the front surface of an adjacent solar cell 112. As a result, the plurality of solar cells in the solar cell row are electrically connected in series.

[0035] The solar cell 112 is directly adhered to the panel 102. In this example, the solar cell 112 includes an outer ETA layer. Before adhering the solar cell 112 to the panel 102, the ETA is slightly softened (by carefully heating), and then the solar cell 112 is pressed against the panel 102. When the softened ETA re-hardens, the solar cell is adhered to the panel 102.

[0036] Figure 2 is only a schematic representation. Those skilled in the art will understand that the solar cells 112 are substantially parallel to the panel 102, even though the solar cells 112 are relatively long compared to their thickness and are thus arranged in an overlapping (shingled) relationship.

[0037] Referring now to FIG. 3, a schematic view of the corner region of the apparatus shown in FIG. 1 is shown. FIG. 3 shows a portion of the panel 102 and a portion of the adjacent solar cell rows 108, 110. In this embodiment, the solar cell row 108 and the solar cell row 110 are perpendicular to each other, and the end surface of the solar cell disposed at the end of the solar cell row 110 overlaps the side portion of the solar cell disposed at the end of the other solar cell row 108. The overlapping portions of the solar cells are electrically connected in series using a conductive adhesive 116 in the same manner as described above with reference to FIG. 2. In a variation of the above-described embodiment, the overlapping portions of the solar cells at the ends of the solar cell rows 108, 110 are electrically insulated from each other, and the solar cell rows 108, 110 are electrically connected in parallel.

[0038] Next, referring to FIG. 4, a partial cross-sectional view of a window unit according to an embodiment of the present invention is shown. Window unit 400 includes panel 102 having cell rows 104, 106, 108, and 110 of first solar cells (for shingle), and these solar cell rows are sealed by ETA layer 109. Panel 102 has a light-receiving surface 103. In this embodiment, panel 102 is the first panel, and window unit 400 also includes a second panel 402 arranged parallel to and spaced apart from the first panel 102. The second panel 402 has solar cell rows 404, and the solar cell rows 404 are directly joined to the second panel 402 in the same manner as described above with reference to FIGS. 1, 2, and 3 for the first panel 102. In this embodiment, panels 102 and 402 are rectangular and each include four solar cell rows. The four solar cell rows are adhered to the ends of panels 102 and 402 and are arranged as shown in FIG. 1. The solar cell rows include a plurality of overlapping (for shingle) solar cells as shown in FIG. 2, and the corners are formed in the manner described with reference to FIG. 3 for the first panel 102.

[0039] Also, window unit 400 includes a frame structure 405, and the frame structure 405 is configured to hold panel 102 and 402 and the solar cell rows in a predetermined position.

[0040] In this embodiment, panels 102 and 404 each include panes of glass, and the panes of glass are each highly transmissive to visible light. In one embodiment, the glass panes forming panels 102 and 404 are formed of low-iron, extra-clear glass panes, and panel 404 further has a low-E (low-emissivity) coating.

[0041] In the embodiment shown in FIG. 4, panel 404 has a laminated structure having three sub-panes 404a, 404b, and 404c. Sub-pane 404a is formed of low-iron ultra-clear glass with a thickness of 4 mm, and the second and third panes 404b, 404c are each formed of ultra-clear glass having a thickness of 4 mm. Sub-panes 404a, 404b, and 404c are mated with each other to form a stack of sub-panes that are substantially parallel to each other. An intermediate layer 410 of polyvinyl butyral (PVB) is disposed between glass plates 404a and 404b. PVB intermediate layer 412 is also disposed between sub-panes 404b and 404c, but PVB intermediate layer 412 also includes a light-scattering element. In this embodiment, the light-scattering element includes a luminescent scattering powder embedded in the PVB, which is also an epoxy that provides an adhesive force. Panel 404 also includes a diffraction grating configured to facilitate the reorientation of light toward the end regions of panel 404 (i.e., toward frame 20) and to facilitate the extraction of light by total internal reflection.

[0042] It should be understood that panel 404 may have any number of panes with any number of intermediate layers. In some embodiments, panel 404 can include a single piece of a light-transmissive material such as glass.

[0043] Panel 404 has an end 411 having a plane that intersects the light-receiving surface 103. In the embodiment of FIG. 2, the angle between end 411 and light-receiving surface 103 is 90°.

[0044] In addition, the window unit 400 has a cell row 414 of the third solar cell. The cell row 414 of the third solar cell faces an end portion 411 and a cavity between the first panel 102 and the second panel 404. The cell row 414 of the third solar cell substantially surrounds the second panel 404 and is arranged to receive light reoriented to an end portion 416 of the second panel 404 by a scattering material and / or a diffraction element (not shown). Further, the cell row 414 of the third solar cell also receives light in a region facing the cavity between the first panel 102 and the second panel 404.

[0045] FIG. 5 shows a power generation device according to a further embodiment of the present invention. FIG. 5 shows a device 500 having a first panel 502 and a second panel 504. The first panel 502 and the second panel 504 are transmissive to at least 70% of the incident visible light (limited by the transmittance of a panel material such as glass). The device 500 includes the above-described solar cell rows 104, 106, 108, 110 arranged at respective end portions of the panels 502, 504 (only the solar cell row 104 is shown in FIG. 5).

[0046] Each of the solar cell rows 104, 106, 108, 110 has a light-receiving surface portion facing the panel 502, and is adhered to the panel 502 so that there is no gap between the solar cell rows 104, 106, 108, 110 and the panel 502. Further, the solar cell rows 104, 106, 108, 110 each have a back surface portion facing the panel 504 and adhered to the panel 504. In this example, the solar cell rows 104, 106, 108, 110 include an outer polyvinyl butyral (PVB) layer or an ethylene vinyl acetate (EVA) layer on the front surface. A sheet of excluded-volume-branched polymers (EVB) or ethylene tetrafluoroethylene (ETFE) is disposed between the panel 502 and the panel 504 such that the sheet is also disposed between the solar cell rows 104, 106, 108, 110 and the back surface of the panel 504. Before adhering the solar cell rows 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 carefully heating), and then the panels 502, 504 are pressed together such that the solar cell rows 104, 106, 108, 110 are disposed between the panels 502, 504. When the softened PVB, ETA, EVB, or ETFE re-hardens, the solar cell rows are sandwiched and adhered between the panels 502, 504 without the need for additional adhesive, thereby forming a laminated structure. The panels 502, 504 protect the solar cell rows 104, 106, 108, 110 and also provide a highly reliable sealing surface on both the front and back surfaces of the device, which is advantageous for window applications.

[0047] In this embodiment, the cell rows of the first solar cell and the cell rows 104, 106, 108, 110, 408 of the second solar cell may be silicon-based solar cells, but instead can be based on any other suitable material such as CdS, CdTe, GaAs, CIS, or CIGS. The cell row 414 of the third solar cell may be CIS-based or CIGS-based, but instead can be based on any other suitable material such as SI, CdS, CdTe, or GaAs.

[0048] Although some specific embodiments have been described, it should be understood that the disclosed unit 400 may be embodied in many other forms. For example, the unit 400 does not necessarily have to be rectangular and, alternatively, may have any other suitable shape (such as circular or rounded shapes, etc.). Further, the panel 404 can include any suitable number of sub-panels. Additionally, the window unit may include a third panel such that a triple-glass unit is formed.

[0049] No discussion of background art throughout this specification should ever be construed as an admission that such background art is prior art, or that such background art is widely known, or forms part of the common general knowledge in the relevant art in Australia or the world.

[0050] Furthermore, those skilled in the art will understand that modifications to the described embodiments are possible. For example, the plurality of solar cell cells in each cell column do not necessarily have to be connected in series. Also, the present device may include a plurality of substantially parallel adjacent solar cell columns. The plurality of substantially parallel adjacent solar cell columns may overlap such that each solar cell cell in the first cell column overlaps with one (or each) solar cell cell in the substantially parallel solar cell column adjacent thereto. The plurality of solar cell cells in the first cell column may be electrically connected in series, or alternatively, may be electrically insulated from each other and electrically connected to each solar cell cell in the second cell column. For example, the plurality of solar cell cells in the first cell column may be electrically connected one by one to the plurality of solar cell cells in the second cell column, and the plurality of solar cell cells in the second cell column may be electrically connected in series. The plurality of solar cell cells in the first cell column and the plurality of solar cell cells in the second cell column may be inclined in the same manner and direction. Alternatively, the plurality of solar cell cells in the first cell column and the plurality of solar cell cells in the second cell column may be inclined in opposite manners and directions. Furthermore, the plurality of solar cell cells in the first cell column and the plurality of solar cell cells in the second cell column may be inclined at the same angle or different angles with respect to the surface normal of the light receiving surface.

Claims

1. A first panel having a region transparent to at least a part of visible light and having a light-receiving surface, A second panel having a region transparent to at least a part of visible light, wherein light received by the light-receiving surface of the first panel first propagates through the first panel before being received by the second panel, and the second panel is arranged substantially parallel to the first panel, At least one first solar cell row, each of the first solar cells having a pair of main surfaces facing each other with opposite electrical polarities, each of the first solar cells overlapping with one of the other first solar cells in the first solar cell row and being electrically connected in series, the at least one first solar cell row being arranged along and close to an end of the first panel and arranged substantially parallel to the light-receiving surface of the first panel along the region transparent to at least a part of visible light, at least one first solar cell row, At least one second solar cell row arranged on the second panel, Comprising, Each of the second solar cells has a pair of main surfaces facing each other with opposite electrical polarities, and each of the second solar cells overlaps with another second solar cell in the second solar cell row, The at least one second solar cell row is close to an end of the second panel and arranged substantially parallel to the light-receiving surface of the first panel, A power generation device.

2. The power generation device according to claim 1, wherein the first panel and the second panel are window panels, and further comprising a frame structure for supporting the first panel and the second panel.

3. The power generation device according to claim 2, provided in the form of a window unit for a building.

4. The power generation device according to claim 2, provided in the form of a heat-insulating glass unit for a building.

5. The power generation device according to any one of claims 1 to 4, wherein the plurality of first solar cells in the first solar cell row are arranged in an overlapping relationship with each other or in a shingle-like arrangement.

6. The plurality of first solar cell in the at least one first solar cell row is joined to the first panel so that no gap is formed between the plurality of first solar cells and the first panel. The power generation device according to any one of claims 1 to 5.

7. The plurality of first solar cells includes an outer layer of a polymer material and is directly joined to the first panel. The power generation device according to claim 6.

8. The polymer material is polyvinyl butyral (PVB) or ethylene vinyl acetate (EVA). The power generation device according to claim 7.

9. The at least one first solar cell row includes a plurality of first solar cell rows. The plurality of first solar cell rows are arranged around the region that is transparent to at least a part of visible light and close to the end of the first panel. The first panel is transparent to at least a part of visible light. The region that is transparent to at least a part of visible light is a central region. The area of the central region is 10 times larger than the area of the first panel where the first solar cell row is arranged. The power generation device according to any one of claims 1 to 8.

10. The at least one first solar cell row includes at least two first solar cell rows arranged along the adjacent ends of the first panel. The power generation device according to any one of claims 1 to 9.

11. Among the at least two first solar cell rows, two adjacent first solar cell rows form an angle with each other and are oriented substantially parallel to the light receiving surface of the first panel. The power generation device according to claim 10.

12. At least one first solar cell in one first solar cell row among the at least two first solar cell rows overlaps with at least one first solar cell in the first solar cell row adjacent to the one first solar cell row. The power generation device according to claim 10.

13. At least one first solar cell in one of the at least two first solar cell rows is overlapped with and electrically connected to at least one first solar cell in a first solar cell row adjacent to the one first solar cell row, so that the at least two first solar cell rows are electrically connected in series. The power generation device according to claim 12.

14. At least one first solar cell in one of the at least two first solar cell rows overlaps with at least one first solar cell in a first solar cell row adjacent to the one first solar cell row and is electrically insulated from the first solar cell, so that the at least two first solar cell rows are electrically connected in parallel. The power generation device according to claim 12.

15. The first solar cell arranged at an end of one of the at least two first solar cell rows overlaps with one first solar cell in the adjacent first solar cell row in such a way as to form an angle with the adjacent first solar cell row. The power generation device according to any one of claims 11 to 14.

16. Two adjacent first solar cell rows among the at least two first solar cell rows are substantially parallel to each other and face the first panel. The power generation device according to claim 11.

17. At least one first solar cell in one of the at least two first solar cell rows overlaps with at least one first solar cell in a first solar cell row adjacent to the one first solar cell row. The power generation device according to claim 15.

18. The at least two solar cell rows include a first first solar cell row and a second first solar cell row arranged adjacent to each other so as to be parallel to each other. All or at least most of the plurality of first solar cells in the first first solar cell row overlap with each of the plurality of first solar cells in the second first solar cell row. The power generation device according to claim 15 or claim 16.

19. The plurality of first solar cell units in the first first solar cell unit row are electrically connected to each of the plurality of first solar cell units in the second first solar cell unit row, and the plurality of first solar cell units in the second first solar cell unit row are electrically connected in series. The power generation device according to claim 18.

20. The first first solar cell unit row and the second first solar cell unit row are electrically insulated from each other. The plurality of first solar cell units in the first first solar cell unit row are connected in series, and the plurality of first solar cell units in the second first solar cell unit row are electrically connected in series. The power generation device according to claim 18.

21. The main surface inclination directions of the plurality of first solar cell units in the first first solar cell unit row and the plurality of first solar cell units in the second first solar cell unit row are the same. The power generation device according to claim 18 or claim 19.

22. The main surface inclination directions of the plurality of first solar cell units in the first first solar cell unit row and the plurality of first solar cell units in the second first solar cell unit row are opposite to each other. The power generation device according to claim 18 or claim 19.

23. The main surfaces of each of the plurality of first solar cell units in the first first solar cell unit row and the plurality of first solar cell units in the second first solar cell unit row are inclined at the same angle or different angles with respect to the surface normal of the light receiving surface of the first panel. The power generation device according to claim 18 or claim 19.

24. The first panel has a substantially rectangular shape with substantially right angles. Two adjacent first solar cell unit rows are arranged at adjacent ends of the first panel such that the two adjacent first solar cell unit rows form a substantially right angle. One first solar cell unit arranged at an end of one of the two adjacent first solar cell unit rows forms an overlapping relationship with a side end of one first solar cell unit arranged at an end of the other first solar cell unit row. The power generation device according to any one of claims 1 to 17. **Claim 25**: Each of the first solar cell and the second solar cell has a front surface portion and a back surface portion. The front surface portion is directly or indirectly joined to the first panel, and the back surface portion is directly or indirectly joined to the second panel. As a result, each of the first solar cells in the first solar cell row and / or the second solar cells in the second solar cell row is directly or indirectly joined to both the first panel and the second panel and is sandwiched between the first panel and the second panel. The power generation device according to any one of claims 1 to 24. **Claim 26**: The at least one second solar cell row disposed on the second panel is joined to the second panel so that no gap is formed between the at least one second solar cell row and the second panel. The power generation device according to claim 25. **Claim 27**: The at least one second solar cell row includes a plurality of second solar cell rows oriented at adjacent ends of the second panel. The power generation device according to claim 26. **Claim 28** The second panel has four ends, and at least one of the plurality of second solar cell rows is disposed at each end of the second panel. The power generation device according to claim 27. **Claim 29**: The plurality of second solar cell rows are oriented at an angle to each other. The power generation device according to claim 27 or claim 28. **Claim 30** At least one second solar cell in one second solar cell row among the plurality of second solar cell rows overlaps with at least one second solar cell in a second solar cell row adjacent to the one second solar cell row. The power generation device according to claim 29. **Claim 31** The second panel has a substantially rectangular shape with substantially right angles, and the plurality of second solar cell rows are disposed at adjacent ends of the second panel such that two adjacent second solar cell rows form substantially right angles. The power generation device according to any one of claims 27 to 30. **Claim 32** The second solar cell is disposed at one end of one of the second solar cell rows, and the end surface of the second solar cell overlaps with the side end of the second solar cell disposed at the end of the second solar cell row adjacent to the one second solar cell row. The power generation device according to claim 31.

33. The power generation device according to any one of claims 1 to 32, wherein the second panel further includes a diffraction element in order to facilitate reorientation of the incident infrared light to an end portion of the second panel.

34. including at least one third solar cell cell row disposed on at least one end surface of the second panel and oriented substantially perpendicular to the main surface of the second panel, The power generation device according to any one of claims 1 to 33, wherein at least one of the third solar cell cell rows is disposed substantially perpendicular to the first solar cell cell row in the first panel and the second solar cell cell row in the second panel.

35. The power generation device according to claim 34, wherein the third solar cell included in the third solar cell cell row is a CIS-based or CIGS-based solar cell.

36. The power generation device according to any one of claims 1 to 35, wherein the first solar cell and the second solar cell are silicon-based.

37. A panel having a region transparent to at least a part of visible light and having a light receiving surface, and at least one solar cell cell row, each solar cell having a pair of main surfaces having opposite electrical polarities and facing each other, each solar cell overlapping with one of the other solar cells in the solar cell cell row and being electrically connected in series, at least one solar cell cell row, comprising The at least one solar cell cell row is disposed along and adjacent to an end portion of the panel, and is disposed along the region transparent to at least a part of visible light and substantially parallel to the light receiving surface of the panel, The panel has a substantially rectangular shape with substantially right angles, The at least one solar cell cell row includes two adjacent solar cell cell rows, The at least one solar cell cell row is disposed at adjacent end portions of the panel such that the two adjacent solar cell cell rows form substantially right angles, One solar cell disposed at an end of one of the two adjacent solar cell cell rows forms an overlapping relationship with a side end of one solar cell disposed at an end of the other solar cell cell row. Power generation device.

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