Self-cleaning behaviour of hydrophobic nanocoating for solar PV panels: Enhancing efficiency and thermal management in dusty environments

Solar photovoltaic (PV) panels play a major role in global clean energy generation. This study examines the effect of nanocoatings on the performance of PV panels when exposed to real, harsh outdoor conditions. For understanding the coating effect on the PV panel performance, the panels were coated with PDMS/Zn-TiO₂, PDMS/Zn-Al₂O₃, and PDMS/Zn-SiO₂ nanocomposites. The performance of coated PV panels was compared with manually cleaned and uncleaned panels. The nanocoating applied was hydrophobic in nature. The panels were characterized using high-resolution transmission electron microscopy (HRTEM), UV-Vis spectroscopy, surface wettability, and scanning electron microscopy (SEM) to study the nanocoating molecular distribution, rate of absorption of solar energy, self-cleaning nature, and surface morphology. The results revealed that nanocoated PV panels exhibited superior electrical and thermal performance compared to manually cleaned and uncleaned panels. Notably, the PDMS/Zn-SiO₂-coating allows 300 nm to 400 nm wavelength of solar radiation, which gives a growth in electrical efficiency by 3.67 %, a drop in panel surface temperature by 9 °C, and a drop in convective and radiative heat transfer rates of 48.8 W/m² and 71.6 W/m², respectively, in comparison to uncleaned panels. All panels were tested over a period of 7 weeks, and among them, the PDMS/Zn-TiO₂, PDMS/Zn-Al₂O₃, and PDMS/Zn-SiO₂ nanocomposite-coated panels showed only a 0.4 % drop in electrical efficiency in comparison to uncleaned panels, which exhibited a drop of about 3.1 % in electrical efficiency. The nanocoating provides a durable, passive, and self-cleaning solution that naturally improves thermal regulation, boosts energy output, and reduces operational costs.