Long-term experiment on p-type crystalline PV module with potential induced degradation: Impact on power performance and evaluation of recovery mode

Abstract

The potential induced degradation (PID) phenomenon of p-type c-Si photovoltaic technology is a severe degradation mode that caught the attention of researchers since it can significantly affect the energy production of the PV plants. Various modeling/lab-tests have been conducted but very few are the in-situ experiments estimating the behavior of PID under real operating conditions on desert climate. In this context, the present work inspects the PID presence in an operational PV plant of a p-type monocrystalline silicon (mono-Si) technology with a capacity of 22,2-kW, installed in a Bsh (Hot semi-arid) climate. Besides, the assessment of the PID's impact on the affected modules have been measured and evaluated using several inspection techniques; electroluminescence (EL), thermography (IR) and I–V curve. Furthermore, we have evaluated the PID recovery process in the affected PV modules, and its first appearance in non-affected modules using a polarity inversion technique. The key finding shows that PID can be considered a significant degradation mode affecting the durability and the power output of crystalline silicon modules. Furthermore, the bias polarity change (to only demonstrate that the PID can be regenerated) can recover the PID causing power losses after a very short period. The results of this study demonstrate that PID can rapidly occur within three months in a semi-arid climate of Morocco.