Chosen diagnostic methods of photovoltaic modules

Solar modules under ordinary working condition are exposed to amount of degradation factors which deteriorate their properties. The most important degradation of PV modules during operation are optical, electrical and thermal degradation. The result of these factors is performance degradation of the modules, or even can caused their fault. It is important to find the cause of the fault and its timely removal. The choice of convenient diagnostic method can reduce financial losses and increases safety of photovoltaic power plant. The example of tests performed on PV modules by using infrared (IR) thermography and, potential induced degradation (PID) are presented in this paper.