Potential induced degradation (PID) study on accelerated stress tested PV modules

High system voltage could increase the leakage current from the active cells/circuit to the grounded module frame. The leakage current could then lead to performance degradation, called potential induced degradation (PID). This study presents the PID results obtained on the fresh modules as well as the modules which were previously subjected to accelerated damp heat test (85°C/85%rh; 1000 hours) and thermal cycling test (-40°C to 85°C; 200 cycles). The PID test was conducted in an environmental chamber by stressing the modules at 85°C, for up to 35 hours at +600V or -600V. Electrical performance and electroluminescence studies were also carried out on the pre- and post-PID tested modules.