Study on the formation and evolution mechanism of dust deposition on solar photovoltaic panels

Dust deposition on solar photovoltaic panels dramatically weakens the panel working operation and service life. In this study, the formation and evolution process of dust deposition on solar photovoltaic panels are studied using a computational fluid dynamics-discrete element model (CFD-DEM) method. Moreover, the dust motion characteristics under different dominant forces are compared, and the factors influencing the dust dynamic behaviours and dust deposition laws are discussed. The results indicate that dust particles can be deposited on the panel owing to the coupled effects of deposition forces, such as gravity, van der Waals forces, liquid bridges, and electric field forces. Meanwhile, dust particles will leave the panel under the action of separation forces, including the contact and drag forces. The significant effect of the liquid bridge force can cause a local dead zone on the panel, thus greatly reducing the panel working performance. The relationships between the dust deposition density and air inlet velocity, initial particle concentration, particle charge density, particle diameter, and air relative humidity are described. These results provide an important theoretical direction for dust removal technologies in practical engineering.