Modeling of Leakage Currents in c-Si PV Modules and Investigation of their Arrhenius Behavior

Photovoltaic (PV) modules operating under high voltage stresses are known to conduct leakage current through different layers consisting of glass, encapsulant, backsheet, etc. Since this leakage current is responsible for Potential Induced Degradation (PID), correlating the leakage current to material properties is important for predictive models for PID dependence on total charge transferred. In this paper, a 2D Finite Element Method (FEM) based model is developed to simulate the leakage current flowing in a c-Si module with front glass-encapsulant-cell-encapsulant-backsheet configuration which is excited with 1000 V. The environmental factors such as temperature and surface wetness are considered and the leakage current and electric field distributions in the module are obtained. The Arrhenius behavior of the leakage current is studied and the dependence of overall activation energy on electrical properties of module materials is analyzed.