Investigation of newly developed thermoplastic polyolefin encapsulant principle properties for the c-Si PV module application

Abstract

Ethylene-vinyl acetate (EVA) is the predominating material of choice for making the encapsulant film for photovoltaic (PV) modules. The easy accessibility, low cost, high transparency, long track record, widespread know-how on processability and performance, and to some extent, ignorance of the criticality of encapsulant film on the long-term performance of PV modules have made EVA, a dominant player in the PV industry. In parallel, due to economic reasons, the majority of encapsulant development has moved to a direction of compromising the quality to meet the cost target. In recent years, the PV industry has started recognizing, polyolefin-based encapsulants as technically superior when compared to EVA. Polyolefin-based encapsulant comes in either a crosslinked or thermo-plastic version. Thermoplastic polyolefin offers several advantages related to processability and performance over the crosslinked version. In the current study, we compare a newly developed thermoplastic polyolefin-based encapsulant and a state of the art EVA encapsulant from different aspects of fundamental material properties, like optical, thermal, mechanical, etc. and discuss their implication on the performance of a solar module.