Fabrication of antireflective superhydrophobic coating for self-cleaning solar panels and study of energy efficiency

Dust accumulation on solar panels decreases its efficacy due to the reflection of radiation by dust particles, which further decreases the amount of radiation reaching the solar cells. Antireflective superhydrophobic coatings based on nano-silica and nano-titania were prepared and applied on glass slides and small solar panels for laboratory scale study. All the coated substrates showed hydrophobic to superhydrophobic nature as confirmed by the contact angle of water drops on the coated glass. Scanning electron microscopy and atomic force microscopy results confirmed the presence of nanostructures on coated surfaces, which was responsible for the superhydrophobic behavior. The coating was also found to be stable in acidic, neutral, and basic solutions and a slight change in contact angle was observed after dipping the coated glass in different pH solutions. The antireflective nature of coated solar panels was also observed, and it was found that the coated side of the solar panel showed less reflection of light compared to the uncoated side. The current–voltage curve (I–V curve) was plotted for uncoated and coated solar panels and, further, fill factor and efficiency were calculated. Dust repelling and cleaning efficiency were also evaluated, and it was found that different types of dust were easily removed from coated panels without leaving behind any scratch marks. From the results, it can be concluded that the antireflective and superhydrophobic coatings are simple and sustainable solutions for cleaner and more efficient solar panels.