Long term degradation of photovoltaic devices under real outdoor operating conditions

Performance losses in photovoltaic (PV) systems are a major impact on the financial viability of photovoltaic energy. The degradation rate (RD) of photovoltaic (PV) modules/systems is expected to be affected by the location of where the devices are installed, which will present different levels of different stresses. In this paper, a database is established by collecting the RD of PV modules/system from different locations based on literature from 1986 to 2011. A statistical analysis of the RD of the selected PV modules is presented. The correlation between their degradation and environmental strain doses are also investigated.