Impact of particulate matter (PM10, PM2.5) on global horizontal irradiance and direct normal irradiance in urban areas

Urban photovoltaic (PV) deployment is a vital strategy for achieving carbon neutrality in cities, yet solar electricity generation often falls short of expectations due to particulate matter (PM) pollution. This study quantitatively analyzes the impact of PM on solar irradiance, a critical factor for effective PV system planning and policy development. Conducted over 28 months in Suwon, Korea, the research investigates PM effects on global horizontal irradiance (GHI) and direct normal irradiance (DNI). The findings reveal significant reductions in solar energy output, with GHI reduced by 11.9 % to 34.3 % and DNI by 22.5 % to 55.4 %, depending on PM concentration and particle size. A novel methodology, incorporating long-term measurements and a rigorous data filtering process, isolates PM impacts from other meteorological factors. These results underscore the importance of integrating air pollution considerations into urban PV planning and energy policy, as PM's influence varies with solar altitude and atmospheric conditions. By offering detailed insights into PM's effects on solar irradiance, this research provides essential guidance for optimizing urban solar energy systems and supports the strategic development of policies to enhance renewable energy solutions, fostering carbon neutrality in polluted urban environments.