A review of self-cleaning coatings for solar photovoltaic systems: theory, materials, preparation, and applications.

Abstract

Photovoltaic power generation is developing rapidly with the approval of The Paris Agreement in 2015. However, there are many dust deposition problems that occur in desert and plateau areas. Traditional cleaning methods such as manual cleaning and mechanical cleaning are unstable and produce a large economic burden. Therefore, self-cleaning coatings, which have unique mechanisms and high adaptability, have attracted wide attention in the photovoltaic industry and scientific community, especially the super-hydrophobic and super-hydrophilic coatings. The paper systematically reviewed the theory, materials, preparation, and applications of the super-hydrophobic and super-hydrophilic coatings on the photovoltaic modules. Super-hydrophobic materials such as organosilicon compounds, fluorinated polymers, and some inorganic materials are popular. TiO2 is widely used to prepare super-hydrophilic coatings on glass covers of photovoltaic panels due to its good photocatalytic activity. CVD-based surface treatment is suitable for preparing photovoltaic self-cleaning surfaces. These methods prepare self-cleaning surfaces by reacting gaseous substances with hot surfaces and depositing them on the surface. They are efficient but difficult to control accuracy. When applied to photovoltaic modules, it is crucial to consider the factors such as self-cleaning, transparency, anti-reflection, anti-icing, and durability. In future research, it is significant to improve the transparency, durability, and self-cleaning properties of coatings.