Development of test procedures for polymer material characterization in view of long-term durability of PV-modules

Solar modules mounted to a subsystem are directly affected by natural weathering. It has been found that certification processes including simulated weathering of UV-radiation, heat and moisture can not guarantee for a specific life time. The use of polymers in a photovoltaic-module (PV-module) is one of the most important factors in aging of PV-modules and therefore a methodological approach for analyzing the aging behavior of the polymeric encapsulate materials is presented here. For extrapolation of degradation processes Arrhenius relationship is used as aging model focusing on simultaneous occurrence of different degradation processes. Results of mechanical tests can give information for numerical simulation of changing load-deflection behavior after aging. Thermal Analysis with DSC or TGA helps to understand structural changes happening in the polymeric material.