Soiling remains a critical global challenge for photovoltaic (PV) systems, reducing power generation and undermining long-term performance. Self-cleaning surface coatings offer a promising mitigation strategy, yet their effectiveness strongly depends on environmental conditions, particularly the availability of water for dust removal. In this paper, development and evaluation of three polysiloxane-based hydrophobic coatings designed to enhance the self-cleaning performance of PV modules is reported. The coatings are synthesized and characterized through optical, morphological, and accelerated UV stability analyses, and their soiling behavior is assessed using an analytical model and year-long field experiments. Model simulations and experimental validation reveal that in the absence of rainfall, fine dust particles (< 5 μm) accumulate similarly on coated and uncoated glass, while larger particles (≥ 5 μm) adhere more readily to coated surfaces. Rainfall, however, substantially improves cleaning efficiency on coated glass, increasing its optical transmittance from 1.1% to 2.24% relative to bare glass. Energy yield modeling for a 10 kWp PV system indicates that the use of the developed coatings can enhance annual power output by up to 6.2%. Seasonal analysis further shows that energy gains following rainfall events can reach 5.1% in wet periods, decreasing to 3.35% during prolonged dry conditions. Techno-economic analysis also indicates the return on investment (ROI) time is much less than any other water-assisted cleaning method. These results demonstrate that hydrophobic polysiloxane coatings can mitigate soiling-induced energy losses and enhance the sustainability of solar power generation, particularly in regions characterized by intermittent precipitation and high dust loads.
Sengupta et al. (Mon,) studied this question.