Real-Time Thermoelectrical Model of PV Panels for Degradation Assessment

In this paper, we develop a new real-time thermoelectrical model of a photovoltaic (PV) panel that takes degradations into consideration. The degradation modes under study are the potential-induced degradation, the light-induced degradation, the ultraviolet light degradation, the moisture-induced degradation, and the cell cracks. The effect of each degradation mode on the equivalent circuit of PV cells is described by equations as a function of environmental conditions and time. The thermal behavior of the PV panels is also addressed by building a thermal model of PV panels taking into consideration the environmental and operational conditions as well as the internal heat sources. At the end, we present a complete thermoelectrical model that treats the degradations as additional events. To assess the degradation impact on the cells, the normalized efficiency is taken as the key performance index.