TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Layer: The backing layer is chosen from glass sheet, polymeric sheet, polymeric film, metal sheet and ceramic plate. The solar cells are wafer-based solar cells chosen from crystalline silicon (c-Si) and multi-crystalline silicone (mc-Si)-based solar cells. The solar cells are thin film solar cells chosen from amorphous silicon, microcrystalline silicon, cadmium telluride, copper indium selenide, copper indium/gallium diselenide, light absorbing dye, and organic semiconductor-based solar cells.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The copolymer precursor comprises copolymerized units (21-23 wt.%) of alpha , beta -ethylenically unsaturated carboxylic acid based on total weight of alpha -olefin carboxylic acid copolymer precursor. The copolymer precursor has melt flow rate of 60 g/10 minutes or less, 25 g/10 minutes or less measured according to ASTM D1238 at 190 degrees C and load of 2.16 kg. The sodium ionomer has melt flow rate of 10 g/10 minutes or less, preferably 5 g/10 minutes or less measured according to ASTM D1238 at 190 degrees C and load of 2.16 kg and flexural modulus of more than 40000 psi (276 MPa) measured according to ASTM D638. The total content of the carboxylic acid groups in copolymer precursor is 20-35%. Preferred Sheet: The sheet has monolayer or multilayer containing sodium ionomer composition. The multilayer has sub-layers in which at least one contains sodium ionomer composition and each other sub-layers comprises at least one polymer chosen from acid copolymer, ionomer, poly(ethylene vinyl acetate), polyvinyl acetal, polyurethane, polyvinylchloride, polyethylene, polyolefin block elastomer, copolymer of alpha -olefin and alpha , beta -ethylenically unsaturated carboxylic acid, silicone elastomer, epoxy resin, and their mixture. The sheet has total thickness of 0.25-1.5 mm, preferably 0.38-0.89 mm. Preferred Module: The solar cell module comprises a front encapsulant layer (12) laminated to the light-receiving side of the solar cell layer and a back encapsulant layer (16) laminated to the non-light-receiving side of the solar cell layer. One of the front and back encapsulant layers is the layer comprising the sodium ionomer composition and the other encapsulant layers comprise polymeric material chosen from copolymer of alpha -olefin and alpha , beta -ethylenically unsaturated carboxylic acid, ionomer of copolymer of alpha -olefin and alpha , beta -ethylenically unsaturated carboxylic acid, poly(ethylene vinyl acetate), polyvinyl acetal, polyurethane, polyvinylchloride, polyethylene, polyolefin block elastomer, silicone elastomer, epoxy resin, and their mixture. The solar cell module further comprises an incident layer (10) and a backing layer (18). The incident layer is chosen from glass sheet, polymeric sheet comprising polymer chosen from polycarbonate, acryl, polyacrylate, cyclic polyolefin, polystyrene, polyamide, polyester, fluoropolymer, and their mixture, and polymeric film comprising polymer chosen from polyester, polycarbonate, polyolefin, norbornene polymer, polystyrene, styrene-acrylate copolymer, acrylonitrile-styrene copolymer, polysulfone, nylon, polyurethane, acryl, cellulose acetate, cellophane, polyvinyl chloride, fluoropolymer, and their mixture.