Advanced Development of PV Encapsulants: Semiannual Technical Progress Report, 30 June 1995 - 31 December 1995

The goals of the NREL PVMaT program are, among others, to reduce module manufacturing costs and to improve the quality and reliability of manufactured PV products. One component critical to the service life of PV modules is the useful life of the ethylene vinyl acetate EVA) resin-based encapsulant that is employed extensively by module manufacturers on a worldwide basis. However, some moduleproducers, end-users, and investigators have reported a yellowing or browning phenomenon with EVA-resin-based encapsulant in the field. Under the NREL PVMaT program, Springborn Laboratories proposed a comprehensive study of the EVA aging and discoloration problem and its possible solution(s). This report summarizes how an accelerated aging technique has been used to develop a series of EVA-basedcandidate encapsulants resistant to discoloration under accelerated testing. These candidates are now under outdoor test in Arizona.;