Evaluation of temperature and humidity on PV module degradation- in field degradation analysis of crystalline silicon module

PV modules operated in humid and hot climate area in different sites with different operating years were investigated. The average degradation rate is 1.18%/y, higher than guarantee of 20% for 25 years (0.8%/y). By investigating modules from 3 plants operating for 3 years, 6 years and 15 years, the influence of operating year on degradation are studied. As reported before, corrosion of metallic materials is considered to be one of the main degradation models. We find linear relationship between FF and Pmax degradation, especially at the case with long operating year.