Underperformance of PV Plants: An Analysis in over 3.3GW

The rapid growth of solar energy and shrinking project margins highlight the need to optimize photovoltaic (PV) plant operation and maintenance (O&M). However, a growing number of installations show deviations between expected and actual production, jeopardizing profitability. This paper presents results from the PhotoVoltaics Evaluation Tool (PVET), developed by Qualifying Photovoltaics S.L. (QPV), applied to over 3.3GW of peak capacity PV plants and 4.2 GW.year of operational data. PVET performs real-time monitoring, data filtering, and in-depth analysis; considering irradiance, module temperature, and electrical performance. Recurrent operational failures—such as inverter shutdowns, tracking failures, open strings, etc—were identified, causing annual energy losses of 1–3% and up to 7.9% in critical cases. Non-recoverable losses, such as grid restrictions, were also identified. PVET’s filtering module enhances fault detection, quantifies energy losses more accurately, and mitigates biases in production assessments. Results demonstrate that advanced data-driven diagnostic tools in PV O&M enable significant loss reduction, improve system reliability and increase project profitability, thus supporting large-scale solar deployment.