Impact of dust accumulation and cleaning strategies on photovoltaic performance: Experimental and simulation analysis in a coastal region of China

Dust accumulation significantly affects photovoltaic (PV) power generation efficiency and has become a critical issue in PV power plant operation and maintenance. This study conducted a 1 yr dust accumulation and cleaning experiment at a PV power station in the coastal region of Guangdong, China. The objective was to analyze the impact of cleaning frequency and methods on power generation and economic performance under different installation tilt angles. Based on the experimental results, we further validated the findings through simulations. The results indicate that power generation increases with higher cleaning frequency; however, the marginal gain from cleaning decreases as the tilt angle increases. Economic analysis shows that for small-tilt-angle (0°–6°) modules, monthly cleaning yields the highest economic returns, whereas for large-tilt-angle (9°–15°) modules, avoiding regular cleaning is more cost-effective. Additionally, the study reveals that unmanned aerial vehicle-based cleaning is economically superior to traditional manual cleaning, piped water cleaning, and automatic sweeping vehicles for both rooftop and ground-mounted PV power stations, especially for large-scale plants. These findings suggest that in the southeastern coastal region, small-tilt-angle rooftop PV systems should undergo regular cleaning, while large-tilt-angle ground-mounted PV systems should reduce cleaning frequency and only be cleaned after severe soiling events to optimize economic benefits.