Monocrystalline silicon photovoltaic mitigation of potential-induced degradation using SiO2 thin film and + 1000 V biasing

Abstract

Potential-induced degradation (PID) of photovoltaic (PV) modules is a severe form of degradation in PV modules, where power losses depend on the strength of the electric field, the relative humidity, and temperature. Therefore, understanding how PID influence the performance of PV modules is fundamental to reducing problems caused by such degradation. Previous studies have only considered single effects of PID; however, this work investigates the power losses and the development of hotspots in two different monocrystalline silicon PV modules. The origin of the hotpots is when the examined modules are being affected by severe PID, which results in cracks and materials deterioration. The first module is SiO2-free, and the second module contains this thin film layer. In addition, a PID mitigation procedure of + 1000 V has been applied and its effect examined on the modules. The modules were examined under electroluminescence (EL) and thermal imaging. Following these PID experiments, it was found that the SiO2 layer is suitable for deploying commercial PV modules to prevent hotspots and PID. However, applying + 1000 V PID mitigation does not necessarily improve the modules' performance after being affected by PID.