Durability of photovoltaic backsheet outer weatherable layers

Photovoltaic backsheets are an essential part of photovoltaic modules. It is imperative that the backsheet perform and be shown to be weatherable over the 25 year expected module lifetime. This paper reports on findings from a study focused on understanding the durability of the outer weatherable layers of commercial backsheets exposed in south Florida. Within one year of exposure, Non-Fluoropolymer outer weatherable layers were found to be degrading, with cracking and erosion of the polymer matrix occurring. In contrast, after four years of exposure there is no evidence of degradation in backsheets protected with a Kynar® PVDF fluoropolymer layer.