Investigation of the degradation of EVA encapsulation of photovoltaic module under different stress factors

Ethylene-Vinyl Acetate (EVA) film is widely used as encapsulation material for Photovoltaic (PV) solar modules. It is a preferable practice to evaluate the product and its associated components at material stage to ascertain confidence on its performance. In this study, the degradation behavior of the EVA encapsulation is investigated under Fluorescence UV radiation, thermal stress and damp-heat conditions. For this study EVA with 33% vinyl acetate content was chosen as it is found to be optimal for encapsulant application. It is observed that after 240 hrs of damp-heat conditioning the material became very sticky and the test was discontinued and the effect of moisture studied by FTIR analysis is discussed. There is no physical change in EVA after thermal ageing of 240 hours and is being continued. Significant degradation in the properties of EVA was observed after 1000 of Fluorescence UV ageing.