Experimental and modeling study of dust composition impact on photovoltaic performance in arid coastal environments

Abstract

This study examines the combined influence of dust composition, humidity, and air quality on the performance of photovoltaic (PV) systems in Jubail, Saudi Arabia—an archetypal arid coastal region. Four dust types (montmorillonite, kaolinite, bentonite, and natural dust) were systematically deposited on polycrystalline PV modules at varying surface densities (1.0–7.0 g/m2) under controlled outdoor conditions in September 2025. Concurrently, atmospheric parameters such as relative humidity, air quality index (AQI), and surface temperature were continuously monitored. SEM-EDX analysis revealed distinct mineralogical compositions: natural dust was rich in silica (25.37 %) and calcium oxide (30.52 %), whereas montmorillonite contained high iron content (62.67 %), influencing both optical transmittance and heat accumulation. Experimental results showed that natural dust caused the greatest power loss (48 % at 6 g/m2), while montmorillonite produced the highest thermal stress (surface temperature reaching 40.4 °C). Elevated humidity (>60 %) further exacerbated efficiency losses (15–30 %) due to enhanced dust adhesion and moisture-induced conductive paths. A modified Kaldellis–Kapsali exponential model (R2 > 0.95) accurately predicted the nonlinear efficiency decline relative to dust density and composition. Diurnal analysis indicated peak generation during low-humidity morning hours (8:00–12:00), with afternoon efficiency dropping by 20–25 % owing to increased moisture and AQI. Correlation analysis identified AQI (R = −0.83) as a stronger predictor of performance degradation than humidity (R = −0.77). These findings establish critical maintenance thresholds (4.0 g/m2 dust density) and support the development of tailored mitigation strategies, including hydrophobic coatings and thermally resistant materials, for sustainable PV operation in harsh desert climates.