Fraunhofer Center for Sustainable Energy Systems

The PV Durability Initiative

Cordula Schmid, David Meakin, Geoffrey Kinsey, Claudio Ferrara, Sandor Stecklum



Solar project financing requires confidence that a plant’s actual energy output will remain close to prediction over the planned lifetime of the plant. To assess PV module reliability, module qualification standards have been developed. For example, IEC 61215 (Crystalline silicon terrestrial photovoltaic (PV) modules) and UL 1703 (“Standard for safety for flat-plate photovoltaic modules and panels) have become the benchmarks for modules fielded globally.


These standards are effective at detecting manufacturing and infant mortality failures, but are insufficient for determining wear-out rates. Due to the pass/fail methodology used in certification testing, assessment of the relative reliability risk and the guidance provided to manufacturers for improvement is also limited. Thus, no commonly accepted testing standard exists which predicts module performance over its expected lifetime. Such quantitative durability data would help module manufacturers differentiate their products and financiers accurately appraise revenue risk. Reduction in the perceived risk of PV plants would ultimately make PV projects more affordable and accelerate PV rollout worldwide.


The Fraunhofer Institute for Solar Energy Systems (ISE) in Germany and the Fraunhofer Center for Sustainable Energy Systems (CSE) in the USA have initiated the Photovoltaic Module Durability Initiative (PVDI) in order to address this challenge. The Fraunhofer PVDI goes beyond infant mortality pass/fail testing to quantitatively rate module performance as modules wear out. The PVDI program combines Highly Accelerated Lifetime Testing (HALT) and long-term outdoor exposure in order to ascertain their correlation. 


This paper presents technical information about the PVDI program; scoring results of the first five solar manufacturers’ are given in the oral presentation during the conference. Long-term outdoor exposure is ongoing.  


Download This Publication in PDF Format