Assessing field performance of flexible PV modules for moisture induced degradation from accelerated testing

The work presented here is aimed at assessing the field performance of flexible photovoltaic (PV) modules with regard to moisture-induced degradation through the use of accelerated testing. A semi-empirical framework for such assessment is developed using a combination of empirical and analytical models. Testing at different temperature and humidity conditions is carried out for representative flexible copper indium gallium selenide (CIGS) based PV module configurations. Test results highlight the limitations of such accelerated testing and it is shown that for the high-moisture-barrier systems tested, the test times can become prohibitive for establishing humidity dependence through accelerated testing. Through the use of empirical models based on the theory of rate processes, a method is proposed to translate test results to field performance using typical meteorological year (TMY) data.