Study of a dust deposition mechanism dominated by electrostatic force on a solar photovoltaic module

Solar energy is one of the most promising renewable energy sources to solve the energy crisis. Dust deposition on solar photovoltaic (PV) modules significantly reduces the power generation of PV power plants. In this paper, the motion characteristics of the gas phase and charging mechanism of dust particles and solar PV glass are investigated by means of the computational fluid dynamics-discrete element model (CFD-DEM) method. In addition, the mechanism and characteristics of dust deposition on a solar PV module as dominated by electrostatic force are discussed. The research results show that frequent collisions between dust particles and PV glass or between dust particles lead to charging. The dust deposition mechanism on a solar PV module is a gas-solid-electrical multi-directional coupling process. There is a great electrostatic field near the solar PV glass, causing charged dust particle deposition. The dust deposition density decreases when the air inlet velocity increases and when the tilt angle of the solar PV module or the number of particle collisions decreases. Different particle dynamics have different dust deposition ratios for different predominant deposition forces (such as the electrostatic force, van der Waals force, and gravity force). The research findings provide an important theoretical basis for dust deposition prevention and removal from solar PV modules.