Comparative Analysis of Potential Induced Degradation in Photovoltaic Modules Under Indian Tropical Climate Conditions

This study investigates Potential Induced Degradation (PID) in solar photovoltaic modules under tropical climate conditions, following IEC TS 62804-1 standards and MNRE guidelines. Five crystalline silicon modules underwent accelerated stress testing at 85°C and 85% relative humidity for 288 hours, with applied voltages of ±1500V. The experimental results revealed significant variations in PID susceptibility among identical modules, with power degradation ranging from 1.32% to 8.36%. Modules under positive voltage bias showed higher degradation compared to those under negative bias. Electroluminescence imaging identified predominant cell degradation adjacent to aluminium frames, while electrical parameter analysis demonstrated notable variations in maximum power current (Imp) between positive and negative bias conditions. Wet leakage current tests revealed substantial reductions in insulation resistance (69.45-78.44%), correlating with morning dew conditions typical in tropical climates. The study highlights the necessity for comprehensive PID testing protocols that consider manufacturing variations and environmental stress factors specific to tropical regions.