Investigation of Bifacial PV modules degradation under desert climatic conditions

In this paper, the degradation of commercially available Bifacial PV module installed under desert climatic conditions for more than four years is investigated. Indoor characterization including IV measurement under STC conditions, electroluminescence imaging and visual inspection were performed to analyze the degradation rate and mechanisms. It has been observed that the front side of the bifacial modules showed higher degradation rate (1.3-1.88%/year) compared to the back side(0.39-0.78%/year). The degradation was mainly driven by the reduction in I
_sc
and Fill-Factor (FF). Ethylene Vinyl Acetate (EVA) discoloration was among the main mechanisms that contributed to the bifacial degradation, resulting in average External Quantum Efficiency (EQE) loss of 9.6% in the wavelength band 400-490nm.