Laminated solar cell interconnection system

Abstract

Thin film photovoltaic cells and strings of cells may be electrically joined in series. More specifically, electrical contacts between photovoltaic cells may be formed by positioning the cells between a pair of interconnection substrates, each of which includes a conductive grid. By positioning the cells appropriately between the substrates, an electrical connection is formed between one polarity of a given cell and the opposite polarity of an adjacent cell.

1 . A photovoltaic module comprising
 a first flexible dielectric sheet having an inner side, and a first conductive grid on the inner side,   a second flexible dielectric sheet having an inner side and a second conductive grid on the inner side of the second flexible dielectric sheet,   an adhesive layer between the first and second flexible dielectric sheets, and   a series of thin film flexible photovoltaic cells sandwiched between the first and second dielectric sheets, wherein the first and second conductive grids overlap near an edge of one of the cells providing electrical interconnection between a top side of one cell and a bottom side of an adjacent cell.   
     
     
         2 . The photovoltaic module of  claim 1 , wherein each sheet has an adhesive layer between the inner side and the conductive grid. 
     
     
         3 . The photovoltaic module of  claim 1 , wherein the conductive grids overlap in a gap between adjacent cells. 
     
     
         4 . The photovoltaic module of  claim 1 , wherein first and second sheets are laminated into a flexible flat package having a side edge, the conductive grids overlapping near the side edge of the package. 
     
     
         5 . The photovoltaic module of  claim 1 , wherein the second dielectric sheet has an outer side provided with a mechanism for attaching the module to a surface of a building. 
     
     
         6 . The photovoltaic module of  claim 5 , wherein the mechanism includes an adhesive. 
     
     
         7 . The photovoltaic module of  claim 1 , wherein each of the first and second sheets is made of one or more of the following materials: polyethylene terephthalate, polyethylene naphthalate, polyetheretherketone, polyimide, and ethylene tetrafluoroethylene. 
     
     
         8 . An interconnected photovoltaic module, comprising:
 a first conductive grid attached to a first substantially transparent substrate;   a second conductive grid attached to a second substrate; and   a plurality of thin film photovoltaic cells disposed between the first and second substrates with a photoactive side of each cell facing the first substrate;   wherein the first and second conductive grids are configured to make electrical contact with each other in regions between adjacent photovoltaic cells and thereby to connect the adjacent photovoltaic cells in electrical series.   
     
     
         9 . The photovoltaic module of  claim 8 , further comprising a first substantially transparent layer of adhesive applied to the first substrate, and a second layer of adhesive applied to the second substrate. 
     
     
         10 . The photovoltaic module of  claim 8 , further comprising dielectric strips disposed between the first and second substrates and configured to prevent electrical short circuits between opposite polarities of each cell. 
     
     
         11 . The photovoltaic module of  claim 10 , wherein the dielectric strips are constructed from a substantially transparent dielectric material. 
     
     
         12 . The photovoltaic module of  claim 8 , wherein the second substrate includes a vapor barrier. 
     
     
         13 . The photovoltaic module of  claim 8 , further comprising a protective lamination layer enclosing the first and second substrates and the photovoltaic cells. 
     
     
         14 . A photovoltaic module comprising
 a first flexible dielectric substrate having a long axis and a width axis, and a series of conductive grid patterns arranged in series along the long axis of the substrate, each grid pattern having a central region including multiple parallel strips of conductive material, and at least one projecting arm region of conductive material connected to the central region,   first and second thin film flexible photovoltaic cells positioned on the first flexible substrate each cell being substantially registered on the central region of one of the grid patterns, each cell having an upper anode surface and a lower cathode surface, and   a second flexible dielectric substrate having a long axis and a width axis, and a series of conductive grid patterns arranged in series along the long axis of the substrate, each grid pattern having a central region including multiple parallel strips of conductive material, and at least one projecting arm region of conductive material connected to the central region, wherein the first and second substrates are laminated together on opposite sides of the photovoltaic cells, with corresponding arm regions from the two substrates overlapping and projecting in opposite directions to establish in series electrical interconnection between the first and second photovoltaic cells.   
     
     
         15 . The photovoltaic module of  claim 14 , wherein each grid pattern has at least two projecting arm regions on opposite sides of the respective central region of the grid pattern. 
     
     
         16 . The photovoltaic module of  claim 14 , wherein each photovoltaic cell has a pair of side edges parallel to the long axis of the substrates, further comprising dielectric strips overlapping the edges of the photovoltaic cells. 
     
     
         17 . The photovoltaic module of  claim 14 , wherein each substrate had a layer of adhesive for bonding the substrates together. 
     
     
         18 . The photovoltaic module of  claim 14 , wherein at least one of the substrates has a layer of adhesive for bonding the substrates together. 
     
     
         19 . The photovoltaic module of  claim 14 , wherein arm regions have holes for increasing surface area bonding of the two substrates together. 
     
     
         20 . The photovoltaic module of  claim 14 , wherein the first and second substrates are identical except one is inverted relative to the other in the final sandwich configuration. 
     
     
         21 . The photovoltaic module of  claim 14 , further comprising positive and negative terminals at opposite ends of the module. 
     
     
         22 . The photovoltaic module of  claim 14 , wherein each photovoltaic cell includes a CIGS layer. 
     
     
         23 . A photovoltaic module comprising
 a first flexible dielectric sheet having a top side adhesive layer, and a first conductive grid on the top side adhesive layer,   a second flexible dielectric sheet having a bottom side adhesive layer, and a second conductive grid on the bottom side adhesive layer, and   a series of thin film flexible photovoltaic cells sandwiched between the first and second dielectric sheets, wherein the first and second conductive grids overlap near an edge of one of the cells providing electrical interconnection between a top side of one cell and a bottom side of an adjacent cell.   
     
     
         24 . The photovoltaic module of  claim 23 , wherein the top and bottom side adhesive layers are heat activated. 
     
     
         25 . The photovoltaic module of  claim 24 , wherein the adhesive layers comprise ionomer. 
     
     
         26 . The photovoltaic module of  claim 23 , wherein the adhesive layers include one or more of the following: ethylene vinyl acetate, polyolefins, ionomers, polyvinyl butyral, and urethane. 
     
     
         27 . The photovoltaic module of  claim 23 , wherein the conductive grids overlap near a gap between two adjacent cells. 
     
     
         28 . The photovoltaic module of  claim 23 , wherein the conductive grids overlap near side edges of the first and second dielectric sheets. 
     
     
         29 . The photovoltaic module of  claim 23 , wherein the first dielectric sheet is substantially transparent. 
     
     
         30 . The photovoltaic module of  claim 23 , wherein each conductive grid is discontinuous. 
     
     
         31 . The photovoltaic module of  claim 23 , wherein the conductive grids are identical, with one grid being inverted relative to the other. 
     
     
         32 . The photovoltaic module of  claim 23 , further comprising
 a dielectric strip on said edge of one of the cells.