Intrinsically Heat Tolerant, UV Resistant EVA/ LDPE thermoplastic elastomeric encapsulant – An alternative for conventional crystalline silicon PV module encapsulant

Cable and Diagnostics Division, Central Power Research Institute, Bangalore – 560 080, India

^* Corresponding author: moumita@cpri.in

Abstract

28% vinyl acetate content Ethylene Vinyl Acetate copolymer (EVA) and Low Density Polyethylene (LDPE) blend is a newly developed thermoplastic elastomeric encapsulating system for silicon Photovoltaic (PV) module. Differential scanning calorimetry (DSC) studies has been revealed the inter-miscibility nature of these two polymers blend in the amorphous zones. Thermogravimetric analysis (TGA) result confirms that the EVA-LDPE blend is more thermal stable than the pristine EVA. Encapsulation provides electrical insulation between the solar cells and the electrical circuit of the PV module. Electrical insulation property in terms of DC surface resistivity (SR) and DC volume resistivity (VR) were studied. Insulation property of EVA-LDPE blends under UV radiation has been explored in this article and the change in insulation property has been correlated with the degradation factors. Accelerated UV ageing was performed as per cycle 2 of ASTM G 154 – 2016 for 1000 hours. The thermal resistance and electrical insulation properties were significantly reduced for pristine EVA after 1000 hours UV ageing while >52% property retention found for EVA-LDPE blend.