Potential of white EVA as PV Encapsulant: Performance and reliability Study

In this work, we study and evaluate the potential of white EVA as encapsulation material in PV modules. As white EVA is highly reflective (with WAR of more than 86%), it improves the module performance due to higher gain from cell-gap compared to a standard backsheet (with WAR of about 72%). For a cell-gap of 3mm and a string-gap of 5mm, white EVA yields a current gain of about 2.5%, whereas standard backsheet has a lower current gain of about 2.2%. Transmittance measurement of white EVA also reveals that it is capable of blocking the ultraviolet (UV) radiation from reaching the backsheet. Thus, white EVA can potentially reduce UV degradation of PV backsheets as it provides enhanced UV filtering. After 270kWh/m
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UV irradiation, no optical degradation and “yellowing” are observed on the backsheets. The reliability of white EVA as encapsulation in PV modules is also studied. After a sequential testing comprising 500 hours of damp heat test and UV irradiation of 65kWh/m
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, mini-modules encapsulated with white EVA do not show evident colour change. Hence, white EVA is a potential alternative encapsulation material to conventional EVA.