Characterizing Solar Panel Encapsulants during Potential Induced Degradation

The high operating voltages experienced by utility-scale solar panels can lead to a set of degradation mechanisms known as potential induced degradation (PID). At high voltages, leakage currents can drive the movement of sodium out of the glass at the front of the module, through the encapsulant, leading to problematic chemical interactions within the PV cell. Though tests have been developed to screen for PID-susceptible modules, the role of the encapsulant and the mechanisms of sodium migration are not yet fully understood. In this work, we investigate the role of humidity, voltage bias, and encapsulant chemistry in the migration of sodium through PV polymeric encapsulants.