Solar irradiance variability and rooftop photovoltaic potential at RAMS Park

Large-scale sports facilities are energy-intensive urban infrastructures where rooftop photovoltaic (PV) applications can reduce grid dependence, yet solar resource variability at stadium-scale sites remains poorly documented. This study examines the temporal and seasonal variability of solar irradiance at RAMS Park Stadium, Istanbul, providing a preliminary, irradiance-based assessment of rooftop PV potential. Daily Global Horizontal Irradiance (GHI), Direct and Diffuse Irradiance, air temperature, and wind speed data for 2024–2025 were obtained from the NASA POWER database and analysed in R using descriptive statistics, seasonal comparisons, moving averages, the Mann–Kendall trend test, Sen’s slope estimation, Seasonal-Trend Decomposition (STL), and irradiance-variability indicators. Results revealed a pronounced seasonal pattern, with higher, more stable GHI in summer and lower, more variable values in winter; mean daily GHI was approximately 4.15 kWh/m 2 /day, and neither the Mann–Kendall test nor Sen’s slope detected a significant trend over the two-year period, while STL confirmed the dominance of the seasonal component. These findings indicate a favourable seasonal irradiance profile for preliminary rooftop PV planning, particularly in summer, although results should be interpreted strictly as an irradiance-based resource assessment rather than a complete PV performance or reliability evaluation, offering a reproducible baseline for future stadium-scale solar feasibility research.