Effect of light irradiation during potential-induced degradation tests for p-type crystalline Si photovoltaic modules

Abstract

Light irradiation during a potential-induced degradation (PID) test for p-type crystalline Si photovoltaic modules was studied under various test conditions. PID progress was clearly delayed by light irradiation. Such effects by light irradiation strongly depended on the wavelength. Clear effects on PID delay were observed in the case of light irradiation with a UV component below approximately 400 nm. On the other hand, almost no effects were observed in the case of light irradiation without a UV component. Delay of PID progress was also observed even under high-humidity condition. It was also found that PID progresses in a partially shadowed region even under UV light irradiation, which means that a partial shadow easily brings about PID for PV modules exposed outdoors.