Characterization of field exposed thin film modules

Test arrays of thin film modules have been deployed at the Solar Energy Centre near New Delhi, India since 2002-2003. Performances of these arrays were reported by O.S. Sastry [1]. This paper reports on NREL efforts to support SEC by performing detailed characterization of selected modules from the array. Modules were selected to demonstrate both average and worst case power loss over the 8 years of outdoor exposure. The modules characterized included CdTe, CIS and three different types of a-Si. All but one of the a-Si types were glass-glass construction. None of the modules had edge seals. Detailed results of these tests are presented along with our conclusions about the causes of the power loss for each technology.