Self-Cleaning Performance of Super-Hydrophilic Coatings for Dust Deposition Reduction on Solar Photovoltaic Cells

Dust deposition on solar photovoltaic (PV) cell surface will significantly decrease the PV power efficiency, as the transmittance of the solar cells would be greatly decreased by the deposited dust particles. This paper aims to study the anti-dust performance of super-hydrophilic coatings for the solar PV cells with water spraying condition. The solar cell covering glass was treated to be super-hydrophilic and compared with the bare glass sample. It was found that many dust particles adhere and aggregate on the uncoated glass while the particles deposited on the super-hydrophilic glass surface are densely distributed. When the water spraying process was conducted, the dust deposition mass for the bare and the coated glass samples are both reduced obviously with the increase time of water spraying. In addtion, dust deposition mass is significantly reduced with the increase of deposition and spraying tilt angles. The self-cleaning efficiency of super-hydrophilic coating on dust deposition is 92% higher than the bare glass cases. The spectral transmittance of glass samples for all the coated cases are significantly higher than that for all the bare cases. The maximum transmittance improvement can reach 26.5% when the deposition tilt angle is 30° and the spraying tilt angle is 60°.