Estimation of potential induced degradation in solar Mini-modules

Abstract

This work includes the quantitative determination of the effect of potential induced degradation (PID) on the performance of solar mini-module. The PID effect has been studied experimentally by applying a DC voltage of −1000 V on the solar modules with respect to module frame at room temperature (25 ± 1°C) for different time durations. The effects were analyzed using current-voltage (I-V) measurements (dark and illuminated) before and after the PID test. The dark current-voltage characteristics of the modules showed increasing trend in the leakage current with PID test duration, indicating the voltage stress led to enhanced recombination of the charge carriers. The cell parameters such as open-circuit voltage (Voc), short-circuit current (Isc) and fill-factor (FF) were also analyzed and a severe degradation was noticed in these parameters. For instance, the FF deteriorated from 76.7% to 41.6% in 42 h of PID test with a significant reduction in Voc and Isc. The degradation mechanism was also analyzed using impedance analysis to gain further insights on solar cell junction and surface. The observed PID degradation of solar modules even at room-temperature reveals that the PID effect is very much significant on the performance of the module and need to be addressed for effective deployment of solar technologies in the field.