Overview of photovoltaic module reliability testing at NREL

The goals of the photovoltaic module reliability testing program at NREL include working with PV manufacturers to improve the long‐term reliability of their modules, as well as obtaining an understanding of the correlation between indoor (accelerated) testing and outdoor (natural) exposure in order to reasonably predict PV module service lifetime. In addition, when problems occur, it is important to perform accurate failure analysis techniques to determine failure mechanisms, and, hopefully, obtain realistic solutions. At NREL, we have developed both indoor and outdoor module reliability testing programs to investigate these various, complex issues. These programs involve module qualification testing, photostability studies, accelerated weathering, and outdoor, real‐time exposure testing. An overview of these various ongoing programs, their goals, approaches, and methods, will be presented here.