Simulation verification and investigation of the effect of dust and panel orientation on panel efficiency in a grid-connected photovoltaic system

The depletion of existing energy sources in recent years and their contribution to environmental pollution have led to an increased shift toward renewable energy sources. Solar energy is highly preferred for energy production due to its renewable, natural, and infinite capacity. To maximize the efficiency of photovoltaic (PV) systems, accurate energy production forecasting, optimal panel orientation, and thorough evaluation of environmental factors are essential. This study analyzes real-time production data collected between November 2024 and October 2025 from a grid-connected solar power plant located on the campus of Zonguldak Bülent Ecevit University, with a total installed capacity of 39.6 kW. These actual data were compared with simulated estimates generated using PVsyst, PVGIS, and HelioScope software tools. Additionally, the performance of PV panels installed in southwest and northeast orientations was evaluated to determine the impact of panel direction on energy yield. A subset of the southwest-facing panels was regularly cleaned, while another subset was left exposed to natural conditions. This allowed for a comparative assessment of the effect of surface dust accumulation on panel efficiency. The results indicate that the PVsyst simulation, utilizing NASA-SSE meteorological data, produced the closest estimates to actual measurements. Furthermore, the southwest-oriented panels demonstrated 30.2 % higher efficiency compared to those facing northeast. Panel cleaning did not result in a significant change in performance throughout the study period.