What are the primary causes of module degradation in the field, and how can these causes be mitigated through proper design and maintenance practices?

Module degradation refers to the gradual decline in the performance of solar panels over time, reducing their power output. The primary causes of module degradation in the field include: Potential-induced degradation (PID), Light-induced degradation (LID), UV degradation of encapsulants, thermal cycling, and mechanical stress. PID is a phenomenon that occurs in PV modules operating at high voltages, causing a significant reduction in power output due to leakage currents. This is worsened by high humidity and temperatures. LID is an initial degradation that occurs within the first few hours of sunlight exposure, primarily affecting crystalline silicon modules. UV degradation of encapsulants, such as EVA, can cause discoloration and reduce light transmission to the solar cells. Thermal cycling, caused by repeated heating and cooling of the modules, can lead to fatigue and cracking of the cells and interconnects. Mechanical stress from wind, snow, or hail can also cause damage to the modules. These causes can be mitigated through proper design and maintenance practices. Using PID-resistant modules, or applying a reverse voltage at night can mitigate PID. High-quality encapsulants with UV stabilizers can reduce UV degradation. Robust module design and installation practices can minimize mechanical stress. Periodic inspections and cleaning can identify and address potential problems early on. Regular thermal imaging inspections can identify hot spots and potential failures.