Manufacturing processes for light concentrating solar module

• US 20090032087A1
• Filed: 09/26/2008
• Published: 02/05/2009
• Est. Priority Date: 02/06/2007
• Status: Abandoned Application

• Current Assignee: American Solar Technologies, Inc.
• Original Assignee: American Solar Technologies, Inc.
• Inventors: Kalejs, Juris P.
• Application Number:
  US12/286,025
• Publication Number:
  US 20090032087A1
• Time in Patent Office: Days
• US Class Current: 136/246
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H01L 31/0504 specially adapted for series or parallel connection of solar cells in a module
• CPC Class Codes: H01L 31/0516 specially adapted for interconnection of back-contact solar cells
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

Solar module manufacturing methods for manufacturing a light concentrating solar module including photovoltaic (PV) cells. The method includes applying an interconnect material to a flexible electrical backplane having preformed conductive interconnect circuitry to form interconnect attachments. The method aligns an array of back contact PV cells with the interconnect attachments. Conductive pathways are formed between the PV cells and the conductive interconnects of the flexible electrical backplane. The method includes providing a light concentrating layer between PV cells that are spaced apart. The method applies an encapsulant material to fill spaces formed between the PV cells and the flexible electrical backplane to form a solar cell subassembly, which is incorporated into the light concentrating solar module.

Claims

1. A method of fabricating a light concentrating solar module having a plurality of photovoltaic cells, each photovoltaic cell having a plurality of conductive contacts located on a back surface of each photovoltaic cell, the method comprising:

feeding a flexible electrical backplane onto a planar surface, said flexible electrical backplane comprising a flexible substrate and a light concentrating layer disposed adjacent to a front surface of said flexible substrate, said flexible electrical backplane having preformed conductive interconnects in contact with interconnect pads exposed on a front surface of said flexible electrical backplane at predetermined locations;

forming a plurality of interconnect attachments in electrical contact with said exposed interconnect pads based on applying an interconnect material onto said exposed interconnect pads;

placing said conductive contacts of said photovoltaic cells in an alignment with said predetermined locations of said interconnect pads and in contact with said interconnect attachments, said predetermined locations determined to provide said alignment for said interconnect pads, said interconnect attachments, and said conductive contacts;

providing an underlay encapsulant to fill a plurality of spaces formed between said back surfaces of said photovoltaic cells and said front surface of said flexible substrate; and

applying a curing process to said underlay encapsulant solidifying said underlay encapsulant and to said interconnect attachments forming a conductive path from each conductive contact through a respective one of said interconnect attachments to a respective one of said interconnect pads.

2. The method of claim 1, wherein said light concentrating layer is a light reflecting metallic material.

3. The method of claim 1, wherein said light concentrating layer comprises a diffractive material.

4. The method of claim 1, wherein said light concentrating layer comprises light redirecting grooves.

5. The method of claim 1, wherein said light concentrating layer comprises a transparent material comprising light redirecting particles.

6. A method of fabricating a light concentrating solar module having a plurality of photovoltaic cells, each photovoltaic cell having a plurality of conductive contacts located on a back surface of each photovoltaic cell, the method comprising:

feeding a flexible electrical backplane comprising a flexible substrate onto a planar surface, said flexible electrical backplane having preformed conductive interconnects in contact with interconnect pads exposed on a front surface of said flexible substrate at predetermined locations;

providing a light concentrating layer disposed adjacent to said front surface of said flexible substrate, said light concentrating layer configured to maintain an exposure of said interconnect pads;

forming a plurality of interconnect attachments in electrical contact with said exposed interconnect pads based on applying an interconnect material onto said exposed interconnect pads;

placing said conductive contacts of said photovoltaic cells in an alignment with said predetermined locations of said interconnect pads and in contact with said interconnect attachments, said predetermined locations determined to provide said alignment for said interconnect pads, said interconnect attachments, and said conductive contacts;

providing an underlay encapsulant to fill a plurality of spaces formed between said back surfaces of said photovoltaic cells and said front surface of said flexible substrate; and

applying a curing process to said underlay encapsulant solidifying said underlay encapsulant and to said interconnect attachments forming a conductive path from each conductive contact through a respective one of said interconnect attachments to a respective one of said interconnect pads.

7. The method of claim 6, wherein said feeding said flexible electrical backplane comprises feeding said flexible electrical backplane from a roll of backplane material and said providing said light concentrating layer comprises feeding said light concentrating layer from a roll of light concentrating material.

8. The method of claim 6, wherein said light concentrating layer is a light reflecting metallic material.

9. The method of claim 6, wherein said light concentrating layer comprises a diffractive material.

10. The method of claim 6, wherein said light concentrating layer comprises light redirecting grooves.

11. The method of claim 6, wherein said light concentrating layer comprises a transparent material comprising light redirecting particles.

12. The method of claim 6, said light concentrating layer having a predetermined pattern of apertures aligned to maintain said exposure of said interconnect pads.

13. The method of claim 6, said light concentrating layer comprising a plurality of encapsulant segments aligned to maintain said exposure of said interconnect pads.

14. A method of fabricating a light concentrating solar module having a plurality of photovoltaic cells, each photovoltaic cell having a plurality of conductive contacts located on a back surface of each photovoltaic cell, the method comprising:

feeding a flexible electrical backplane onto a planar surface, said flexible electrical backplane comprising a flexible substrate and a light concentrating layer disposed adjacent to a front surface of said flexible substrate, said flexible electrical backplane having preformed conductive interconnects in contact with interconnect pads exposed on a front surface of said flexible electrical backplane at predetermined locations;

forming a plurality of interconnect attachments in electrical contact with said exposed interconnect pads based on applying an interconnect material onto said exposed interconnect pads;

placing said conductive contacts of said photovoltaic cells in an alignment with said predetermined locations of said interconnect pads and in contact with said interconnect attachments, said predetermined locations determined to provide said alignment for said interconnect pads, said interconnect attachments, and said conductive contacts;

applying a thermal process to said interconnect attachments forming a conductive path from each conductive contact through a respective one of said interconnect attachments to a respective one of said interconnect pads;

depositing a liquid underlay encapsulant flowing to fill a plurality of spaces formed between said back surfaces of said photovoltaic cells and said front surface of said flexible substrate; and

applying a curing process to said liquid underlay encapsulant solidifying said liquid encapsulant.

15. The method of claim 14, wherein said light concentrating layer is a light reflecting metallic material.

16. The method of claim 14, wherein said light concentrating layer comprises a diffractive material.

17. The method of claim 14, wherein said light concentrating layer comprises light redirecting grooves.

18. The method of claim 14, wherein said light concentrating layer comprises a light transparent material comprising light redirecting particles.

19. A method of fabricating a light concentrating solar module having a plurality of photovoltaic cells, each photovoltaic cell having a plurality of conductive contacts located on a back surface of each photovoltaic cell, the method comprising:

feeding a flexible electrical backplane comprising a flexible substrate onto a planar surface, said flexible electrical backplane having preformed conductive interconnects in contact with interconnect pads exposed on a front surface of said flexible substrate at predetermined locations;

providing a light concentrating layer disposed adjacent to said front surface of said flexible substrate, said light concentrating layer configured to maintain an exposure of said interconnect pads;

forming a plurality of interconnect attachments in electrical contact with said exposed interconnect pads based on applying an interconnect material onto said exposed interconnect pads;

placing said conductive contacts of said photovoltaic cells in an alignment with said predetermined locations of said interconnect pads and in contact with said interconnect attachments, said predetermined locations determined to provide said alignment for said interconnect pads, said interconnect attachments, and said conductive contacts;

applying a thermal process to said interconnect attachments forming a conductive path from each conductive contact through a respective one of said interconnect attachments to a respective one of said interconnect pads;

depositing a liquid underlay encapsulant flowing to fill a plurality of spaces formed between said back surfaces of said photovoltaic cells and said front surface of said flexible substrate; and

applying a curing process to said liquid underlay encapsulant solidifying said liquid encapsulant.

20. The method of claim 19, wherein said feeding said flexible electrical backplane comprises feeding said flexible electrical backplane from a roll of backplane material and said providing said light concentrating layer comprises feeding said light concentrating layer from a roll of light concentrating material.

21. The method of claim 19, wherein said light concentrating layer is a light reflecting metallic material.

22. The method of claim 19, wherein said light concentrating layer comprises a diffractive material.

23. The method of claim 19, wherein said light concentrating layer comprises light redirecting grooves.

24. The method of claim 19, wherein said light concentrating layer comprises a transparent material comprising light redirecting particles.

25. The method of claim 19, said light concentrating layer having a predetermined pattern of apertures aligned to maintain said exposure of said interconnect pads.

26. The method of claim 19, said light concentrating layer comprising a plurality of encapsulant segments aligned to maintain said exposure of said interconnect pads.

27. A light concentrating solar module comprising:

a transparent front cover having a front surface and a back surface;

a plurality of photovoltaic cells;

each photovoltaic cell having one front surface facing said transparent front cover and one back surface facing away from said transparent cove; and

each photovoltaic cell having a plurality of back contacts on each back surface thereof;

a back cover spaced apart from and substantially parallel to said transparent front cover, said plurality of photovoltaic cells disposed between said transparent front cover and said back cover;

a light transmitting encapsulant disposed between said transparent front cover and said back cover;

a light concentrating layer disposed between said photovoltaic cells and said back cover, said transparent front cover transmitting light through said transparent front cover and incident on said light concentrating layer in regions between said photovoltaic cells, said light concentrating layer directing said light towards said transparent front cover, and said front surface of said transparent front cover internally reflecting said light back towards said photovoltaic cells;

a flexible electrical backplane comprising a flexible substrate and a plurality of conductive interconnects preformed thereon in a predetermined pattern; and

a plurality of interconnect attachments each disposed between one of said conductive interconnects and one of said back contacts of one of said photovoltaic cells.

28. The solar module of claim 27, wherein said flexible electrical backplane comprises said light concentrating layer.

29. The solar module of claim 27, wherein said light concentrating layer is provided in said regions between said photovoltaic cells adjacent to said flexible electrical backplane.

30. The solar module of claim 27, wherein said light concentrating layer is a light reflecting metallic material.

31. The solar module of claim 27, wherein said light concentrating layer comprises a diffractive material.

32. The solar module of claim 27, wherein said light concentrating layer comprises light redirecting grooves.

33. The solar module of claim 27, wherein said light concentrating layer comprises a transparent material comprising light redirecting particles.

34. The solar module of claim 27, said flexible substrate having windows disposed adjacent to said back surfaces of said photovoltaic cells, each window adjacent to a respective one of said photovoltaic cells.

35. The solar module of claim 27, said light transmitting encapsulant comprising an overlay layer of transparent material disposed adjacent to said back surface of said transparent front cover and an underlay layer of transparent material disposed adjacent to said back surfaces of said solar cells;

said overlay layer of transparent material comprising at least one encapsulating sheet adjacent to said front surfaces of said solar cells, and an additional layer of encapsulant disposed between said back surface of said transparent front cover and said at least one encapsulating sheet;

said additional layer having a density less than said transparent front cover, and replacing a volume of said transparent front cover equal to a volume of said additional layer.

36. The solar module of claim 27, wherein said conductive interconnects and said light concentrating layer form intervals between said conductive interconnects and said light concentrating layer, said intervals providing an electrically insulating separation between said conductive interconnects and said light concentrating layer and providing areas of moisture permeability for moisture flow between said light transmitting encapsulant and said flexible electrical backplane.

37. The solar module of claim 27, further comprising encapsulant segments disposed adjacent to the back surfaces of said solar cells, providing encapsulating material adjacent to said solar cells and providing moisture permeability between said light transmitting encapsulant and said flexible electrical backplane.