Impact of Solar Cell Cracks Caused During Potential-Induced Degradation (PID) Tests

Potential-induced degradation (PID) of photovoltaic (PV) modules is one of the most severe types of degradation in modern modules, where power losses depend on the strength of the electric field, the temperature and relative humidity, and the PV module materials. Understanding how module defects impact PID is key to reducing the issue. This work investigates the impact of cracks and fractural defects in solar cells and their impact on PID. We have tested using electroluminescence (EL) imaging how solar cells with varying levels of cracks/defects impact PID and our results indicate that such defects have a sizeable influence on the PID. We also confirmed the strong relationship between the size of the initial defect/crack and the presence of hotspots. As the crack (dark) area increased, there was a further increase in the cell's temperature under standard test conditions (STCs). In this work, it is observed that minor cracks in solar cells have no considerable PID effect for the solar cells providing some reassurance that quality control can reduce this degradation pathway.