Investigation of c-Si modules degradation and recovery effect under high potentials: CV-PID

In recent years several failure modes of PV modules operated under high potentials were observed. Most dominant today is the degradation mechanism called “potential induced degradation (PID)” of crystalline PV modules [1]. This shunting mechanism of c-Si solar cells can cause dramatic power losses in not grounded installations operated at higher system voltages. For thin film PV modules a phenomenon called TCO corrosion [2] was mainly discussed but other mechanisms exist [3]. Each failure mode might require different environmental conditions to be observable in the field and also to be reproducible in the laboratory by an accelerated test setup. Herein the focus is only on one particular failure mode of c-Si modules, usually called PID.