Potential-induced degradation

Potential-induced degradation (PID) is a potential-induced performance degradation in crystalline photovoltaic modules, caused by so-called stray currents. This effect may cause power loss of up to 30 percent.

The cause of the harmful leakage currents, besides the structure of the solar cell, is the voltage of the individual photovoltaic (PV) modules to the ground. In most ungrounded PV systems, the PV modules with a positive or negative voltage to the ground are exposed to PID. PID occurs mostly at negative voltage with respect to the ground potential and is accelerated by high system voltages, high temperatures, and high humidity.