Degradation of Crystalline Silicon Photovoltaic Cells/Modules under Heat and Temperature Effect

Abstract

Temperature is extremely significant to the PV modules degradation process, especially hot spots, encapsulant bleaching, delamination failure on interconnections, corrosion, discoloration, and bubbles on the panel’s surface. We investigated the degradation of crystalline silicon PV cells/modules exposed under heat and temperature effect. We established a qualitative correlation between the electrical parameters affected and the different modes of PV cells/modules degradation. We reveal that: the leakage current increase rapidly with increasing number of hot spots. The effect of discoloration causes loss of transmittance of the encapsulant EVA, and reduces the photocurrent density (Jph) owing to a decrease of absorption, and therefore the power loss. Discoloration does not affect the fill factor (FF) and (Voc) more, but the corrosion causes a decrease of the PV modules maximal power (Pmax) when the delamination of the PV module reduces the thermal conductivity locally and hence increases the temperature of the cell. Delamination, bubbles, corrosion, hot pots, EVA discoloration are the predominant modes of the PV cells/ modules degradation.