Impact of the module backsheet components on the electrical field performance of PV-plants

This study links chemical analysis of PV-module's backsheet components with the power output of PV-systems during their lifetime. Several PV-systems all with two or more module types and also backsheet types were investigated. We identified three classes of backsheet types with respect to their influence on the module performance. While PV-modules with robust backsheets (e.g. double-fluoropolymers) perform constantly well over years, others show linear or even exponential performance losses, while others display total failure (e.g. single-fluoropolymers or non-fluoropolymers). Humidity is a most probable driving factor for the faster ageing process of modules with critical backsheets in terms of their chemical layer components and the resulting properties.