Integrated energy and fault audit and performance degradation modeling of a solar photovoltaic plant

This paper presents an integrated energy and fault assessment of a 2.5 MWp solar photovoltaic (SPV) plant in Pune, India, through a comprehensive audit achieved by following a unique top-down sequential approach through analysis of real-time field data. A year-long field study was conducted, evaluating system parameters through thermal imaging, electrical testing, and environmental monitoring. The results highlight 27% power loss in dry seasons due to soiling, 15% PR drop from the design benchmark of 80%, and recurrent faults in the PV system. These empirical observations along with hotspot detection with temperatures as high as 88 °C by thermal imaging provide actionable improvements for site management and predictive maintenance. A degradation model is proposed, which is statistically validated based on the real-time field data that provide a comprehensive framework for quantifying performance degradation in SPV systems by incorporating key parameters of soiling, shading, environmental, maintenance, aging, and external weather factors. A novel aspect of this study is the integration of these multifactorial degradation influencers into a unified model framework, which is statistically validated using nonlinear regression (R2 ≈ 0.9971, RMSE ≈ 0.365%) and cross-validation metrics. Sensitivity analysis highlighted the importance of short circuit current degradation and soiling ratio as key monitoring parameters for optimal SPV performance. By addressing critical research gaps, this work provides actionable insights for stakeholders and underscores the necessity of tailored maintenance strategies to sustain and enhance the long-term efficiency of SPV plants.