Outdoor stability performance of CIS and CdTe photovoltaic modules at SERI

The Solar Energy Research Institute (SERI) has been conducting tests to study the outdoor stability performance of currently leading polycrystalline thin-film technologies of copper indium diselenide (CIS) and cadmium telluride (CdTe) modules and submodules. Stability performance results from tests conducted at SERI on CIS and CdTe thin film material prototype modules and submodules over a period of more than one year are discussed. From the test data, it appears that the stability characteristics of CIS modules exhibit little or no degradation over the initial testing period at SERI. One CdTe submodule exhibited no change in performance over the test duration. Despite promising results, there appears to be some need to improve the encapsulation system on these polycrystalline thin film materials to ensure full 30 year reliability