Solar array device with structural electrical connections

Abstract

A solar array device and a method for constructing a solar array device are provided. [Solution] A solar cell array assembly includes a first solar cell having a first side and a second side, a second solar cell stacked below the first cell, the second cell having a first side and a second side, and a structural conductor disposed between the first cell and the second cell, the structural conductor selected to support at least the weight of the first cell to maintain a selected distance between the first cell and the second cell, and the structural conductor electrically coupled to the second side of the first cell and the first side of the second cell.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 381,977, filed November 2, 2022, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to solar array devices having structural electrical connections. [Background technology]

[0003] Prior art discloses the application of photovoltaic cells on multiple horizontal slats that can be installed on the outside of a window, the inside of a window, or the inside of a multi-pane window (Gilliard US 5221363, Field US 4137098). Other art describes photovoltaic cells embedded horizontally or at an angle in transparent materials, including window glass (Paull US 2021 / 0273125, Edmonds US 2008 / 0257403).

[0004] An intended advantage of this technology may be that the window can generate valuable photovoltaic electricity while still maintaining high window transparency. An additional advantage may be the ability to use proven, highly efficient silicon photovoltaic cells, avoiding optical and other losses that may be inherent in other photovoltaic window technologies, such as luminescent concentrators. [Brief explanation of the drawings]

[0005] Features and advantages of various embodiments of the claimed subject matter will become more apparent as the following detailed description proceeds and by reference to the drawings in which like numerals designate like parts and in which:

[0006] [Figure 1A] 1 shows a front view (or rear view) of a solar array according to an embodiment of the present disclosure. [Figure 1B]1 shows a top view of an exemplary representative solar cell. [Figure 1C] 1 shows a bottom view of an exemplary representative solar cell. [Figure 1D] A cross-sectional view of the array 100 taken along line XX in FIG. 1A is shown. [Figure 1E] 1B shows a perspective view of two cells of the array of FIG. 1A. [Figure 2] 1 illustrates a tiled arrangement of a solar array installed within a window according to an embodiment of the present disclosure. [Figure 3A] Columns of the array of FIG. 2 are shown. [Figure 3B] 3B shows a cross-sectional view taken along line XI-XI in FIG. 3A. [Figure 3C] 3B shows a cross-sectional view taken along line XI-XI in FIG. 3A. [Figure 4A] 1 illustrates a manufacturing technique according to one embodiment of the present disclosure. [Figure 4B] 1 illustrates a manufacturing technique according to one embodiment of the present disclosure. [Figure 5] FIG. 10 shows a side view of a solar array according to another embodiment of the present disclosure.

[0007] The following detailed description proceeds with reference to exemplary embodiments, many of which may be apparent to those skilled in the art. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present disclosure describes solar array devices and methods for constructing solar array devices. In the embodiments described herein, the solar array device includes a plurality of solar cells in a stacked array, with each solar cell connected to adjacent solar cells using structural conductors. The cells can include an array of relatively narrow solar cells, whereby the solar cells are oriented horizontally or at a shallow angle from horizontal, which may be, for example, 1 to 35 degrees from horizontal, and arranged in rows to create a vertical stack. The individual solar cells are connected by structural electrical connectors, preferably via solder, conductive adhesive, or other means known in the art. The structural electrical connectors, attached to the bus pads of the solar cells, make the array a self-supporting, relatively rigid structure or cell grid that can stand on its own, for example, without a substrate or additional support.

[0009] Advantageously, by eliminating the need for a substrate to support the cells, the teachings of the present disclosure provide a solar module that can include bifacial photovoltaic cells, thus allowing the cells to generate electricity from both their bottom and top surfaces. The solar cells may be formed, for example, from crystalline silicon and / or other relatively rigid solar cells known in the art. The solar cells may have widths ranging from 3.0 mm to 15.0 mm, although other widths may be used. The center-to-center spacing between rows may vary considerably, with larger spacing providing somewhat better transparency but less power output, and smaller spacing providing somewhat less transparency but generating more power. An exemplary range for the center-to-center spacing between rows may be 0.3 to 2.0 times the solar cell width, although other ratios may also be used. This solar cell grid may be particularly useful as a power-generating photovoltaic array inside an insulated glass window unit.

[0010] In one exemplary embodiment, one or more solar arrays may be incorporated into an insulated glass window unit. For example, one or more solar arrays may be incorporated between the panes of an insulated glass window, which may contain two or more panes, i.e., in the cavity between two panes of glass in an insulated glass window. In this embodiment, optical coatings typically applied to insulated glass windows, such as low-emissivity coatings, may be applied to the surface of the window assembly so as not to reduce the light reaching the solar cell grid. The cavity between the glass surfaces containing one or more solar grid modules may be filled with air or an inert gas such as argon, as known in the art, or with a transparent fluid such as silicone oil or mineral oil. Fluid-filled insulated glass windows can reduce light reflection losses that would otherwise occur at the interface between the glass and the air inside the window due to differences in refractive index. Fluid-filled windows can also help dissipate heat generated by the solar cells.

[0011] FIG. 1A illustrates a front view (or rear view) of a solar array 100 according to an embodiment of the present disclosure. The array 100 includes a plurality of solar photovoltaic cells (solar cells) 102A, 102B, ..., 102N in a stacked arrangement. In some embodiments, the width of a cell is substantially less than the length of the cell. The plurality of solar cells 102A, 102B, ..., 102N may be stacked substantially horizontally (as shown) and substantially parallel to one another. In other embodiments, the plurality of solar cells 102A, 102B, ..., 102N may be stacked at an angle to the horizontal and may be spaced apart non-parallel to one another. The solar cells 102A, 102B, ..., 102N may be monofacial (power generation from one side) and / or bifacial to generate power from light incident on both the top and bottom surfaces of the cell. Each of the solar cells 102A, 102B, ..., 102N may be formed using conventional and / or proprietary solar cell structures, such as crystalline silicon cell structures (e.g., polysilicon and monocrystalline silicon cells) and / or other rigid or semi-rigid solar cell structures. The length (L) of each solar cell 102A, 102B, ..., 102N in the array 100 may be selected based on, for example, operating environment constraints, the structural integrity of the individual cells, weight constraints, the desired overall voltage / current / power generated by the array 100, etc. In some embodiments, the length L of each cell 102A, 102B, ..., 102N may be approximately the same or different. For example, different cell lengths may provide aesthetic enhancements when the array 100 is placed between the panes of a window. In some embodiments, the cell length (L) may be a standardized, common length, such as 156 mm.

[0012] 1A shows bifacial cells 102A, 102B, ..., 102N arranged in a stack to form array 100. As is known for bifacial cells, each cell has a polarity designated with a "+" on the top side of each cell 102A, 102B, ..., 102N and a "-" on the bottom side of each cell 102A, 102B, ..., 102N. The cells 102A, 102B, ..., 102N shown in FIG. 1A are coupled in series with each adjacent cell, and total power for array 100 may be taken off leads 111(+) and 113(-), which represent the DC voltage generated by array 100.

[0013] FIG. 1B shows a top view of an exemplary representative solar cell, e.g., representative solar cell 102A. The top side of cell 102A is designated as the positive (+) polarity side of the cell. Cell 102A may include one or more conductive bus pads 106A, 106B, ..., 106I, with each bus pad 106A, 106B, ..., 106I reflecting the total positive potential generated by cell 102A. Providing multiple bus pads 106A, 106B, ..., 106I along the length (L) of cell 102A may operate to reduce resistive losses. Cell 102A has an overall width (W) that may be selected based on, for example, operating environment constraints, desired overall voltage / current / power generated by array 100, etc. Each of the other cells 102B, ..., 102N in the array (FIG. 1A) may be similar to representative cell 102A shown in FIG. 1B.

[0014] FIG. 1C shows a bottom view of an exemplary representative solar cell 102A. The bottom side of cell 102A is designated as the negative (−) polarity side of the cell. The negative side of cell 102A includes one or more conductive bus pads 108A, 108B, ..., 108I, with each bus pad 108A, 108B, ..., 108I representing the total negative potential generated by cell 102A. Bus pads 108A, 108B, ..., 108I are vertically aligned with bus pads 106A, 106B, ..., 106I, as is conventional in the art. Other cells 102B, ..., 102N in the array (FIG. 1A) may be similar to the representative cell 102A shown in FIG. 1C. As is understood in the art, one side of a cell may be more efficient than the other side of the cell (which may be of either polarity), and in some embodiments, the most efficient side of each cell may be selected to face upward.

[0015] 1A , an array of structural conductors 104A, 104B, ..., 104J is disposed between each cell 102A, 102B, ..., 102N to provide structural integrity for the array 100 and electrical connection between the cells. Each conductor 104A, 104B, ..., 104J is electrically coupled (e.g., soldered) to a corresponding top bus pad 106A, 106B, ..., 106I and bottom bus pad 108A, 108B, ..., 108I on an adjacent cell. In an exemplary embodiment, each conductor 104A, 104B, ..., 104J may be formed as a "hoop" of relatively thin wire, such as pre-tinned, uninsulated copper wire. As a general matter, the structural conductors are formed to provide support to each of the cells above a given cell, i.e., to reduce or eliminate movement or displacement of the cells relative to one another. By way of example, the gauge of the wire forming each conductor 104A, 104B, ..., 104J may be on the order of (0.005 inches, 127 microns) to (0.032 inches, 813 microns), although a wider range of wire diameters may be used depending on the number of conductors and the spacing between cells 102A, 102B, ..., 102N. Conductors 104A, 104B, ..., 104J may be relatively flexible and have a diameter slightly larger than the space between adjacent cells, e.g., in the range of 2% to 15% larger, to facilitate hoop positioning and provide reliable electrical contact to the bus pads prior to soldering. Conductors 104A, 104B, ..., 104J may be formed from multiple windings of wire, which can enhance capillary action during soldering, drawing the solder around the hoop, and adding additional structural support to the cell grid.

[0016] FIG. 1D shows a cross-sectional view of array 100 taken along line XX in FIG. 1A. In the example of FIG. 1D, conductors 104A, 104B, ..., 104J are formed as approximately circular "hoops" and soldered to each adjacent cell. In some embodiments, the "hoops" may be oval, triangular, rectangular, polygonal, etc., and / or other geometric forms such as "C-shaped," "U-shaped," "S-shaped," "Z-shaped," and / or linear conductors. In some embodiments, structural conductors 104A, 104B, ..., 104J may be solid materials, such as relatively thin copper plates, preferably 1 mm to 3 mm thick, that provide sufficient structural support for array 100 when soldered or otherwise bonded to adjacent cell bus pads. FIG. 1E shows a perspective view of two cells of array 100, e.g., cells 102B and 102C. FIG. 1E shows the connections between conductors 104A, 104B, . . . , 104J and bus pads 106 and 108 of cells 102B and 102C.

[0017] FIG. 2 illustrates a tiled arrangement 200 of solar arrays installed within a window in accordance with an embodiment of the present disclosure. In this exemplary embodiment, a 3×3 tiled arrangement of arrays 100A, 100B, ..., 100I is shown installed between the panes of a window, i.e., a double-paned window. The window typically includes a frame 202 made from metal spacers that separate and support the glass panes. As is known in the window art, a sealant, such as hot-melt butyl, silicone, or other adhesive, is applied to the outside of the spacer frame to hold the glass panes and spacers together. The frame 202 may be formed from wood, metal, composite materials, etc., and typically uses aluminum spacers and plastic corner inserts, etc. Electrical connections between the arrays 100A, 100B, ..., 100I can be formed in various ways, as will be understood by those skilled in the art. For example, the arrays in each horizontal row (e.g., arrays 100A, 100B, and 100C) may be electrically coupled to each other in series, such that the voltage of that row is represented by the sum of the voltages of the arrays in that row. Each row may then be electrically coupled together in series or parallel. In other embodiments, the arrays within each vertical column (e.g., arrays 100A, 100D, and 100G) may be electrically coupled together in series, such that the voltage of that column is represented by the sum of the arrays within that column. Each column may then be electrically coupled together in series or parallel. In still other embodiments, each array may be coupled together in series or parallel. The selection of the series and / or parallel coupling of arrays may be based, for example, on a target overall maximum voltage that may be delivered by the window unit. The power generated by arrays 100A, 100B, ..., 100I may be coupled to an inverter system (not shown) or may form part of an alternative power source for a building, etc. In some embodiments, an insulating connector (not shown) may be used within the window structure.

[0018] In some embodiments, to reduce complexity in connecting the arrays, the arrays may be oriented so that a common polarity aligns between the first row (arrays 100A, 100B, 100C) and the second row (arrays 100D, 100E, 100F) and between the second row and the third row (arrays 100G, 100H, 100I). FIG. 3A illustrates this concept, showing columns of arrays 100A, 100D, and 100G from FIG. 2. As shown, the polarity (-) of the bottom surface of the bottom cells of array 100A matches the polarity (-) of the top surface of the top cells of array 100D. Similarly, the polarity (+) of the bottom surface of the bottom cells of array 100D matches the polarity (+) of the top surface of the top cells of array 100G. A single lead 320 may be used for a common polarity for arrays 100A and 110D, and a single lead 322 may be used for a common polarity for arrays 100D and 100G. Of course, these concepts can be extended to multiple columns and / or rows of arrays, as shown in FIG. 2. The electrical connection between the bottom cells of array 100A and lead 320 can be made using structural conductors 304A, as described herein. Similarly, the electrical connection between lead 320 and the top cells of array 100D, the electrical connection between the bottom cells of array 100D and lead 322, and the electrical connection between lead 322 and the top cells of array 100G can be made using structural conductors, as described herein. 3B and 3C show cross-sectional views along line XI-XI of FIG. 3A, illustrating lead 320 and structural conductors 304A and 304B (FIG. 3B), and lead 322 and structural conductors 304C and 304D (FIG. 3C). Conductors 304A, 304B, 304C, and 304D may be formed in a similar manner to other structural conductors in the array to provide visual consistency across panels of the tiled array. In some embodiments, leads 320 and / or 322 may be formed with similar dimensions, appearance, and spacing as adjacent solar cells, again maintaining visual consistency.

[0019] 4A-4B illustrate a fabrication technique according to one embodiment of the present disclosure. In particular, FIGS. 4A-4B illustrate a fabrication technique for forming a solar cell array having structural conductors between each cell of the array 400, as shown in array 100 of FIG. 1A. FIG. 4A illustrates a cross-sectional view of array 400 (similar to the views shown in FIGS. 1D, 3C, and 3D). In this embodiment, a continuous portion of conductive material 440 is aligned with the bus pads of each cell 402A, 402B, ..., 404N of array 400. The continuous conductive material 440 is formed as a serpentine pattern of alternating thin loops 442A, 442B, ..., 442X and thick loops 444A, 444B, ..., 444Y. Each of the thin loops 442A, 442B, ..., 442X has a loop dimension approximately equal to the thickness of a cell 402A, 402B, ..., 404N. Each of the thick loops 444A, 444B, ..., 444Y has a loop dimension approximately equal to the desired or target spacing between each of the cells 402A, 402B, ..., 404N. The thick loops 444A, 444B, ..., 444Y may be soldered to the bus pads of each cell. In FIG. 4B , the continuous conductive material 440 may be trimmed to remove portions of the continuous conductive material 440 that extend beyond the width of the cells 402A, 402B, ..., 404N. This trimming process may be accomplished in a single step using, for example, mechanical cutting, laser cutting, etc. The thick loops remain, thus forming the structural conductors 404A, 404B, ..., 404N between each of the cells. In the example shown in FIGS. 4A and 4B , the structural conductors 404A, 404B, ..., 404N are formed to have a "C-shape." Of course, in other embodiments, the shape of the structural conductor may include "hoops" and / or other shapes, as discussed above.

[0020] FIG. 5 illustrates a side view of another solar array 500 according to another embodiment of the present disclosure. In particular, FIG. 5 illustrates a window pane having a solar cell array. In this exemplary embodiment, the array 400, fabricated using the techniques described above with reference to FIGS. 4A and 4B, is attached to one side of a window pane 550. For example, adhesive 554 may be disposed at one or more junctions 560A, 560B, ..., 530N of the array's cells and structural conductors. The adhesive 554 is generally selected to adhere to the surface of the window pane 550 to reduce or eliminate movement of the array 400 relative to the window pane 550 and may include glue, silicone, or the like. While a single window pane 550 is shown in FIG. 5, in other embodiments, the array 400 may be disposed between window panes.

[0021] Accordingly, one embodiment of the present disclosure provides a solar cell array assembly including: a first solar cell having a first side and a second side; a second solar cell stacked below the first cell, the second cell having a first side and a second side; and a structural conductor disposed between the first cell and the second cell, the structural conductor selected to support at least a weight of the first cell to maintain a selected distance between the first cell and the second cell, the structural conductor electrically coupled to the second side of the first cell and the first side of the second cell.

[0022] Another embodiment of the present disclosure provides a solar cell array panel. The panel includes a plurality of solar cell arrays electrically coupled to each other. Each solar cell array includes a first solar cell having a first side and a second side, a second solar cell stacked below the first cell, the second solar cell having the first side and the second side, and a structural conductor disposed between the first cell and the second cell. The structural conductor is selected to support at least the weight of the first cell to maintain a selected distance between the first cell and the second cell, and the structural conductor is electrically coupled to the second side of the first cell and the first side of the second cell.

[0023] Another embodiment of the present disclosure provides a solar window assembly with solar power generation. The window assembly includes a first pane, a second pane adjacent to the first pane, a frame housing the first pane and the second pane, and a solar cell array. The solar cell array includes a first solar cell having a first side and a second side, a second solar cell stacked below the first cell, the second solar cell having the first side and the second side, and a structural conductor disposed between the first cell and the second cell. The structural conductor is selected to support at least the weight of the first cell to maintain a selected distance between the first cell and the second cell, and the structural conductor is electrically coupled to the second side of the first cell and the first side of the second cell.

[0024] In yet another embodiment, the present disclosure provides a method for manufacturing a solar cell array. The method includes aligning continuous portions of conductive material with bus pads of a first solar cell and a second solar cell. The continuous portions of conductive material are formed in a serpentine pattern of alternating thin and thick loop portions. Each thin loop portion has a loop diameter approximately equal to a thickness of the first and second solar cells, and each thick loop portion has a loop diameter approximately equal to a target spacing between the first cell and the second cell.

[0025] The method also includes soldering the thick loop portion to bus pads of the first solar cell and the second solar cell.

[0026] The method further includes removing a thin loop portion of the conductive material at a point flush with the width of the first solar cell and the second solar cell.

[0027] As used herein, terms such as "side," "front," "rear," "top," "bottom," and the like are provided as aids to explanation, and not as limitations or specific orientations. While the principles of the present invention have been described herein, it should be understood by those skilled in the art that this description is made by way of example only and is not a limitation on the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by those of ordinary skill in the art are deemed to be within the scope of the present invention, and the present invention is not to be limited except as by the following claims.

Claims

1. 1. A solar cell array assembly comprising: a first solar cell having a first side and a second side; a second solar cell stacked below the first cell, the second cell having a first side and a second side; a structural conductor disposed between the first cell and the second cell, the structural conductor selected to support a weight of at least the first cell to maintain a selected distance between the first cell and the second cell, the structural conductor electrically coupled to the second side of the first cell and the first side of the second cell.

2. 10. The solar cell array assembly of claim 1, wherein the first cell and the second cell are bifacial solar configured to generate power on both the first side and the second side of the first cell and the second cell.

3. 10. The solar cell array assembly of claim 1, wherein said structural conductors are formed from wires having diameters that vary from approximately 0.005 inches to 0.032 inches.

4. 2. The solar cell array assembly of claim 1, wherein the first cell and the second cell are bifacial solar configured to generate power on both the first side and the second side of the first cell and the second cell, the first cell and the second cell have bus pads disposed on the first side and the second side, and the structural conductors are soldered to the bus pads on the second side of the first cell and the first side of the second cell.

5. 10. The solar cell array assembly of claim 1, wherein the structural conductors are formed to have a continuous circular, elliptical, rectangular, triangular, or polygonal shape.

6. 10. The solar cell array assembly of claim 1, wherein the structural conductors are formed having a "C" shape or a "U" shape.

7. A solar cell array panel, A plurality of solar cell arrays electrically coupled to each other, each solar cell array comprising: a first solar cell having a first side and a second side; a second solar cell stacked below the first cell, the second cell having a first side and a second side; a structural conductor disposed between the first cell and the second cell, the structural conductor selected to support at least a weight of the first cell to maintain a selected distance between the first cell and the second cell, the structural conductor electrically coupled to the second side of the first cell and the first side of the second cell.

8. 8. The solar cell array panel of claim 7, wherein the first cell and the second cell of each array are bifacial solar configured to generate power on both the first side and the second side of the first cell and the second cell.

9. 8. The solar cell array panel of claim 7, wherein said structural conductors are formed from wires having a diameter of between about 0.005 inches and 0.032 inches.

10. 8. The solar cell array panel of claim 7, wherein the first cell and the second cell of each array are bifacial solar configured to generate power on both the first side and the second side of the first cell and the second cell, the first cell and the second cell having bus pads disposed on the first side and the second side, and the structural conductors are soldered to the bus pads on the second side of the first cell and the first side of the second cell.

11. 8. The solar cell array panel of claim 7, wherein the structural conductors are formed to have a continuous circular, elliptical, rectangular, triangular, or polygonal shape.

12. 8. The solar cell array panel of claim 7, wherein the structural conductors are formed with a "C" shape or a "U" shape.

13. 8. The solar cell array panel of claim 7, wherein the arrays are electrically coupled to each other in series.

14. 8. The solar cell array panel of claim 7, wherein the arrays are electrically coupled in parallel with each other.

15. 8. The solar cell array panels of claim 7, wherein the arrays are electrically coupled together in both series and parallel to produce a target maximum voltage for the panels of the array.

16. 1. A solar window assembly with solar power generation, comprising: a first window pane; a second pane adjacent to the first pane; a frame that houses the first pane and the second pane; A solar cell array, a first solar cell having a first side and a second side; a second solar cell stacked below the first cell, the second cell having a first side and a second side; a structural conductor disposed between the first cell and the second cell, the structural conductor selected to support a weight of at least the first cell to maintain a selected distance between the first cell and the second cell, the structural conductor electrically coupled to the second side of the first cell and the first side of the second cell. Solar window assembly.

17. 17. The solar window assembly of claim 16, wherein the first cell and the second cell are bifacial solar configured to generate power on both the first side and the second side of the first cell and the second cell.

18. 17. The solar window assembly of claim 16, wherein the structural conductor is formed from a wire having a diameter of between about 0.005 inches and 0.032 inches.

19. 17. The solar window assembly of claim 16, wherein the first cell and the second cell are bifacial solar configured to generate power on both the first side and the second side of the first cell and the second cell, the first cell and the second cell have bus pads disposed on the first side and the second side, and the structural conductors are soldered to the bus pads on the second side of the first cell and the first side of the second cell.

20. 17. The solar window assembly of claim 16, wherein the structural conductor is formed to have a continuous circular, oval, rectangular, triangular, or polygonal shape.

21. 17. The solar window assembly of claim 16, wherein the structural conductor is formed having a "C" shape or a "U" shape.

22. 17. The solar window assembly of claim 16, further comprising an adhesive disposed at a junction of the first solar cell and the structural conductor, the adhesive adhering to a surface of the first pane.

23. 1. A method of manufacturing a solar cell array, comprising: aligning a continuous portion of conductive material with bus pads of a first solar cell and a second solar cell, the continuous portion of conductive material being formed in a serpentine pattern of alternating thin and thick loop portions, each thick loop portion having a loop diameter approximately equal to a target spacing between the first cell and the second cell, and each thin loop portion having a loop diameter smaller than each thick loop; soldering the thick loop portion to the bus pads of the first solar cell and the second solar cell; removing the thin loop portion of the conductive material at a point flush with the width of the first solar cell and the second solar cell; A method comprising:

24. 24. The method of claim 23, further comprising placing the first solar cell and the second solar cell bonded together with the conductive material between a first pane and a second pane of a window.

25. 25. The method of claim 24, further comprising placing an adhesive at the interface between the material and at least the first solar cell, the adhesive selected to adhere to the first pane or the second pane.

26. 24. The method of claim 23, wherein the first cell and the second cell are bifacial solar configured to generate power on both a first side and a second side of the first cell and the second cell.

27. 24. The method of claim 23, wherein the material is formed from wire having a diameter that varies from about 0.005 inches to 0.032 inches.

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