A multicriteria analysis of the potential degradations of a photovoltaic module to assess its robustness

Photovoltaic (PV) modules in service undergo more or less severe degradation depending on their operating environments, ages and technologies. In this work, we investigated the coupled influence of the climatic conditions of operation and of the degree of deterioration of a PV module on its energy production. We considered four silicon PV modules characterized in standard test conditions. The PV conversion is modeled by a single diode model taking into account the presence of a fault. Matlab/Simulink software was used to calculate the energy supplied at a constant load for the PV module with and without defects. The ratio between the energy produced with fault and without fault allowed to quantify the percentage of loss. This loss was plotted according to the degrees of degradation of the short-circuit current Isc, the open-circuit voltage Voc, the series resistance Rs and the shunt resistance Rsh. It is shown that when irradiance is held constant, the energy loss is lower with increasing temperature for Isc and Rsh, and vice versa for Voc and Rs. While the temperature is kept constant, the energy loss is lower when the irradiance increases for Isc and Rsh, and inversely for Voc and Rs. A multicriteria analysis enabled to determine the most robust module among the four ones.