Experimental analysis of elevated temperature and soiling loss on the rooftop PV modules performance under composite climatic conditions

On-field performance of a solar PV plant completely relies on solar radiation intensity and its availability. During operation, the output of a solar PV module varies from its rated capacity due to weather parameters such as ambient temperature, humidity, rainfall, wind, and dust. The primary objective of the study is to experimentally evaluate the combined effect of elevated temperature, soiling, and wind-driven convective cooling on rooftop PV performance under composite climatic conditions of North India, which are less explored compared to arid or temperate regions. During the investigation, the effects of elevated operating temperature, daily soiling accumulation, and wind-driven convective cooling on a 500 Wp rooftop PV setup monitored at five-minute intervals throughout June. The results reveal that elevated cell temperatures peaking at 64.0 °C caused an average daily efficiency reduction of 12.0%, with a 9.6% decline in output power directly attributable to temperature effects. Maximum soiling loss was calculated about 0.47% per day with a total monthly loss of 10.2% with some occasional showers cleaning the module by the end of the month. Convective heat loss from the roof mounted PV array was found to be 16.19% higher than a simulated ground-mounted system due to elevated wind exposure, contributing to a 2.27% improvement in energy yield. This study is based on a pilot-scale rooftop installation monitored for a single month. While results were normalized for broader applicability, the scope remains limited, and findings should be interpreted accordingly. The findings highlight that rooftop PV system is simultaneously affected by thermal and soiling effects, and both require explicit consideration at the design stage. Enhanced wind exposure can provide a natural and maintenance-free cooling benefit over ground-mounted systems. Site-specific cleaning schedules are essential to prevent daily dust accumulation.