The effect of encapsulant discoloration and delamination on the electrical characteristics of photovoltaic module

Discoloration and delamination (D&D) of encapsulant in a photovoltaic (PV) module affect the electrical characteristics. Therefore, in this study D&D-induced degradations are investigated with a 25-year-old PV module. The average power output of 25-year-old PV modules decreased by 17.9% compared to initial value. However, insulation properties have been stable over 25 years. Electroluminescence image shows that discoloration has an effect on the cell degradation. The effect of D&D on the light reflectance and transmittance is evaluated by performing a trapezoidal integration with the standard global reference spectrum. Failure analysis reveals that delamination occurs at the interface between encapsulant and solar cell and also shows that corrosion of solder occurred near delamination site (C) 2013 Elsevier Ltd. All rights reserved.