Investigation of seasonal dust accumulation intensity at four PV power plants surrounded by different types of agricultural areas in a hot and humid climate.

In Thailand, photovoltaic (PV) power plant performance is reduced by up to 3% per month due to soiling, which contributes to higher maintenance costs. This study evaluates the dust deposition on four PV power plants from different environments: rice, cassava, corn, and sugarcane fields, and rock blast mines. Dust was quantified based on every two-weeks of one-year-exposed microscope slide samples with the taken microscope picture analyzed by ImageJ software to assess the dust area fractions. The highest dust accumulation was at PV plants close to rock blast area (27.84% in January), followed by cassava and corn farms (22.97% in December), rice fields, cassava, and corn farms, (18.00% in December) and only rice fields (15.21% in February). During the rainy season, dust accumulation rate was small, with rates below ±0.01% per day, reaching maximum averages of 0.47% per day during winter months. Additionally, dust particle size and weight density varied significantly among sites, influenced by local dust sources and environmental conditions. Wind speed and localized rainfall also played a role in dust removal, but site-specific dust generation was the dominant factor affecting accumulation trends. These findings can be implementing a proper cleaning schedule.