EVA for Glass/Glass Solar PV Modules: Effect of encasulant storage conditions and process parameters

This work investigates t the effectiveness of glass-glass solar PV module structures used in combination with a EVA as an encapsulant material. The use of EVA in glass-glass structures is in principle discouraged, as a bioproduct of its photo-degradation is acetic-acid, which cannot be released outside the module- as in the case of glass/foil structures - potentially leading to several degradation modes. In particular, the work focuses on the effect of non-optimal EVA storage conditions. The presence of trapped water absorbed when EVA is stored can affect the long-term degradation of the modules. We as well considers photodegradation of polymers under UV exposure and their impact on modules performance. Well-stored EVA shows no sign of degradation up to a UV dose of 504 kWh/m(2), corresponding to approximate to 8-9 years of outdoor exposure in central Europe regions. The effect of poor polymer storage appear firstly after a cumulative UV dose higher than 180 kWh/m(2), corresponding to approximate to 3-4 years of outdoor exposure in a mid-latitude country with a temperate climate.