Impact of rain and soiling on potential induced degradation

The electrical potential between the cells and ground can cause leakage currents that are a necessary but not sufficient indicator for potential induced degradation that is because of the migration of sodium ions into the silicon cells. Outdoor exposure of modules with high-voltage bias in two different climate regions with monitoring of the climatic data, the module temperatures as well as the leakage currents was used to investigate the effect of rain-induced and soiling-induced increase of the surface conductivity, the leakage current and the decrease of the module performance.