Performance Evaluation of a 1.5 MW Ground-Mounted PV System at PLTGU Grati Using Measured Data and PVsyst Simulation with Consideration of Local Albedo Effects on Inverter Performance

Abstract

This study evaluates the performance of a 1.5 MW ground-mounted photovoltaic (PV) system installed at PLTGU Grati, Indonesia, using measured operational data and PVsyst simulation. Based on the 2025 dataset, the PV system achieved an annual energy production of approximately 2.32 GWh, slightly exceeding the simulated output of 2.28 GWh, with a positive deviation of about 1.7%, while monthly deviations range from approximately +18% to −24% due to environmental variability. The system demonstrated stable performance with an average performance ratio (PR) of approximately 80.6% and a capacity factor (CF) of around 17.7%, indicating efficient operation under tropical conditions. Furthermore, the influence of ground surface albedo on inverter performance is observed, where higher-reflectivity surfaces such as white gravel (≈0.30–0.45) provide greater reflected irradiance compared to soil (≈0.12–0.18) and vegetation (≈0.20–0.25), contributing to output variations of approximately 5–10% at the inverter level. These findings highlight the importance of incorporating local environmental factors, particularly albedo and surface characteristics, to improve the accuracy of PV system performance evaluation and modeling.