Title:	Durability of Polyolefin Encapsulation Based Modules: A Cross-Comparison of Commercially Available Solutions
Author(s):	B.X.J. Yu, R. Lv, J.-N. Jaubert, G. Xing, J. Dupuis, E. Lajoie-Mazenc, C. Dugué, G. Goaer
Keywords:	Encapsulant/s, PV Module, Polyolefin, Delamination, Discoloration
Topic:	Photovoltaic Modules and BoS Components
Subtopic:	PV Module Design, Manufacture, Performance and Reliability
Event:	37th European Photovoltaic Solar Energy Conference and Exhibition
Session:	4AV.1.49
Pages:	1065 - 1067
ISBN:	3-936338-73-6
Paper DOI:	10.4229/EUPVSEC20202020-4AV.1.49
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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Historically, the encapsulation material used in solar panels is ethylene vinyl acetate (EVA) copolymer. As the quality and the durability of the encapsulant are becoming more significant to the photovoltaic (PV) module lifetime, nowadays the PV industry is starting to evaluate alternative material, such as polyolefin. While there are many studies on the degradation and stability of EVA as encapsulation materials, research on the durability of polyolefin is very limited. Here, we conducted accelerated aging tests, including damp-heat, UV with or without moisture, and full spectrum light with water spray, on various commercially available polyolefin encapsulant samples. Polymer-glass adhesion, transmittance, and IR spectra were measured to quantitatively determine the delamination and discoloration of the polyolefin encapsulant, two of the major field failure modes observed for older PV module generations. We found that despite initial deterioration, good adhesion remained at the polyolefin and glass interfaces after 4000 hours of damp-heat exposure, close to the EVA and glass interfacial adhesion. Both polyolefin elastomers (POE) and EVA demonstrated strong UV resistance and high transmittance, slightly better than thermoplastic polyolefin (TPO). Overall, we found that both EVA latest generation and POE with low moisture permeability, with high resistance to microclimate stresses, represent a suitable approach to ensure longer-term service life for PV modules.