The evaluation of degradation caused by dust accumulation on photovoltaic (PV) systems is critical to ensuring optimal energy exploitation in the Sahel region. This study investigates the impact of dust accumulation on the performance of monocrystalline silicon PV modules under a Sudano-Sahelian climate, with a particular emphasis on the physical properties of the dust. Results indicate a significant decrease in extractable electrical power with increasing dust levels, primarily due to a reduction in the fill factor (FF). This decline stems from the shadowing effect of dust particles that partially block incident solar radiation, thereby reducing the effective illumination of the cell surface. While dust has little effect on light absorption and only marginally affects carrier thermalization, it significantly influences the electrical characteristics by increasing the series resistance particularly when conductive organic matter is present. Dust samples collected from the site were classified as silt loam, with particle sizes ranging between 2µm and 20µm
(USDA classification). These sizes, being comparable to the wavelengths of visible light (0.4µm - 0.7µm), promote scattering and contribute to optical losses. The average dust deposition rate was 39.683 g.m-2.day-1, highlighting the need for appropriate mitigation strategies. Maintenance protocols combining periodic blowing and water cleaning can reduce water usage and lower overall maintenance costs.

Dust accumulation; Absorption phenomenon; Thermalization mechanism; Thermodynamic process; Fill factor; Silicon PV module