A Review of Dust Deposition Mechanism and Self-Cleaning Methods for Solar Photovoltaic Modules

Abstract

Large-scale solar photovoltaic (PV) power plants tend to be set in desert areas, which enjoy high irradiation and large spaces. However, due to frequent sandstorms, large amounts of contaminants and dirt are suspended in the air and deposited on photovoltaic modules, which greatly decreases the power efficiency and service life. To clean PV to improve efficiency, many methods were proposed. It was found that the application of the self-cleaning coating on PV modules can effectively reduce dust deposition and improve the efficiency of PV. This paper reviews the dust deposition mechanism on photovoltaic modules, classifies the very recent dust removal methods with a critical review, especially focusing on the mechanisms of super-hydrophobic and super-hydrophilic coatings, to serve as a reference for researchers and PV designers, and presents the current state of knowledge of the aspects mentioned above to promote sustainable improvement in PV efficiency. It was found that the behaviors of dust on photovoltaic modules are mainly deposition, rebound, and resuspension. Particles with a diameter of 1–100 μm are most easily deposited on photovoltaic modules. The use of self-cleaning coatings, especially super-hydrophobic coatings, is beneficial to the rebound and resuspension of particles. The research gaps and development prospects of self-cleaning coatings are also discussed in this paper.

Hydrophobic and Transparent Tantalum Pentoxide-Based Coatings for Photovoltaic (PV) Solar Panels

“…Table 2 includes the average CA and the mean deviation values for the three films. Dust deposition on the PV is highly influenced by water bonded to the glass surface [27][28][29]. If the glass surface is hydrophobic, the quantity of water remaining on the surface is lower, and the dust cannot adhere to the surface.…”

“…The literature data reported thin films obtained by various methods [17][18][19][20][21][22][23][24][25][26]. The implementation of light management textures in thin film solar cells often simultaneously causes an unwanted deterioration of electronic performance [27][28][29]. A simple but effective technique for improving light absorption in thin-film solar cells consists of printing pyramidal textures on the sun-facing side of the glass superstrate [27].…”

Analysis of the Deposition of Pollutants on the Surface of Photovoltaic Modules

“…An interesting overview It is considered that environmental conditions, relative humidity, wind speed, temperature, dust particle size, and concentration all have important effects on dust accumulation. Of all the factors that affect the efficiency of photovoltaic module production, there are outdoor factors such as altitude, dust, humidity, temperature, wind speed, hail, and selffactors such as the tilt angle, material, quality, and maintenance of PV modules [8]. Dust, in cooperation with other particles in the atmosphere, causes the scattering of solar radiation by the process of reflection, absorption, and dispersion, which negatively impacts the performance of the solar PV module [9].…”

Soiling Effect and Remedial Measures of Solar Photovoltaic System Performance in Kuwait

“…Moreover, relative humidity significantly affects adhesive strength; approximately 98% of adhesion in wet environments is due to capillary forces, but van der Waals forces dominate in dry environments. In addition, the surface's roughness factor is a crucial component of capillary forces, and as it increases, the capillary force weakens [5]. Two natural processes, rebound and resuspension, can remove dust from PV surfaces.…”