Solar cell modules with improved backskin

• US 6,660,930 B1
• Filed: 06/12/2002
• Issued: 12/09/2003
• Est. Priority Date: 06/12/2002
• Status: Expired due to Fees

• Current Assignee: Schott Solar Incorporated
• Original Assignee: RWE Schott Solar Incorporated
• Inventors: Gonsiorawski, Ronald C.
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US10/171,021
• Time in Patent Office: 545 Days
• Field of Search: 136/251, 136/244, 257/433, 257/788, 257/789, 257/790, 438/66, 438/80, 438/64, 438/67, 427/74
• US Class Current: 136/251
• CPC Class Codes: B32B 17/1033 Laminated safety glass or glazing containing temporary protective coatings or layers
• CPC Class Codes: B32B 17/10743 containing acrylate (co)polymers or salts thereof
• CPC Class Codes: B32B 17/10788 containing ethylene vinylacetate
• CPC Class Codes: B32B 17/10816 by pressing
• CPC Class Codes: B32B 17/10871 in combination with particular heat treatment
• CPC Class Codes: H01L 31/049 Protective back sheets
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A laminated solar cell module comprises a front light transmitting support, a plurality of interconnected solar cells encapsulated by a light-transmitting encapsulant material, and an improved backskin formed of an ionomer/nylon alloy. The improved backskin has a toughness and melting point temperature sufficiently great to avoid any likelihood of it being pierced by any of the components that interconnect the solar cells.

Claims

1. A laminated solar cell module comprising:

a front support layer formed of a light transmitting material and having first and second surfaces;

a plurality of interconnected solar cells having a first surface facing said front support layer and a second surface facing away from said front support layer;

a transparent encapsulant surrounding and encapsulating said interconnected solar cells, said transparent encapsulant being bonded to said second surface of said front support layer; and

a backskin having a first surface facing said second surface of said front support layer and bonded to said transparent encapsulant and said solar cells, said backskin comprising an ionomer/nylon alloy in sheet form.

2. A module according to claim 1 wherein said ionomer/nylon alloy has a melting point of at least about 200°

C.

3. A module according to claim 1 wherein said ionomer/nylon alloy is approximately 42% ionomer and 58% nylon by weight.

4. A module according to claim 1 wherein said transparent encapsulant is a zinc ionomer.

5. A module according to claim 1 wherein said cells are silicon solar cells.

6. A module according to claim 1 wherein said cells are thin film solar cells and said front support layer constitutes the substrate on which said thin film solar cells are formed.

7. A module according to claim 1 wherein said backskin alloy contains a UV reflecting white pigment.

8. An assembly for conversion under heat and pressure into a laminated solar cell module, said assembly comprising:

a front support layer formed of a light transmitting material and having front and back surfaces;

a first transparent thermoplastic encapsulant layer adjacent the back surface of said front support layer;

a plurality of interconnected solar cells having first and second surfaces adjacent said first transparent encapsulant layer;

a second transparent thermoplastic encapsulant layer disposed adjacent said solar cells in parallel relation to said first transparent encapsulant layer; and

a thermoplastic backskin layer comprising an ionomer/nylon alloy in sheet form.

9. A method of manufacturing a solar cell module comprising:

providing a front support layer formed of a light transmitting material and having front and back surfaces;

placing a first transparent thermoplastic encapsulant layer adjacent the back surface of said front support layer;

positioning a plurality of interconnected solar cells having first and second surfaces so that said first surfaces thereof are adjacent said first transparent encapsulant layer;

placing a second transparent thermoplastic encapsulant layer adjacent said second surfaces of said solar cells;

placing a thermoplastic backskin layer adjacent said second transparent thermoplastic encapsulant layer to thereby form an assembly;

subjecting said assembly to heat and pressure so as to melt said encapsulant layers and cause the encapsulant to surround said cells, and

cooling said assembly so as to cause said encapsulant to solidify and bond to said front support layer, said cells and said backskin, whereby to laminate said layers and said solar cells together to form an integrated solar cell module;

characterized in that said backskin layer comprises an ionomer/nylon alloy.

10. Method according to claim 9 wherein said ionomer/nylon alloy has a melting point of at least about 200°

C.

11. Method according to claim 9 wherein said alloy is in sheet form and has a corona-treated surface.

12. Method according to claim 9 further including the step of positioning a porous scrim layer between said solar cells and said backskin layer before said assembly is subjected to heat and pressure.

13. Method according to claim 9 wherein said encapsulant is a zinc ionomer.

14. Method according to claim 9 wherein said assembly is laminated by subjecting it to a pressure of at least 390 to 410 torr while heating it to a temperature of about 120°

C.

15. Method according to claim 9 wherein said encapsulant is EVA or an ionomer.

16. In a photovoltaic module of the type having an array of electrically interconnected photovoltaic cells encapsulated between a transparent front panel and a back sheet by a light-transmitting encapsulant, the improvement wherein said back sheet is an ionomer/nylon alloy.

17. The photovoltaic module according to claim 16 wherein said encapsulant is an ionomer or EVA.

18. The photovoltaic module according to claim 16 wherein each of said cells has front and back contacts and said cells are interconnected by conductors that have been soldered in place using an acidic flux, and at least some of those conductors have stress relief loops or bends.