The solar energy incident on the Earth’s surface during an hour is almost equal to the one-year total consumption on Earth. When the solar radiation penetrates the atmosphere, a significant amount of its energy is lost due to the fact that Sun radiation is absorbed by solid particles and droplets in the atmosphere and reflected by water vapour and air molecules. But the solar radiation is also absorbed by dust and another type of pollutants as well as scattered backwards, decreasing the direct solar radiation component and causing an increase of the diffuse component. For this reason, the urban and polluted areas typically receive less of the total solar radiation in reference to the clean air of the countryside or industry-free rural areas (Darwish et al. 2018; Robaa 2004). Among the varied practical applications of renewable energy, photovoltaic modules received much attention in electrical power generation and became widely used because of their low production and low maintenance cost as well as their relatively good efficiency of energy conversion which nowadays reaches 26.3% for a single-junction terrestrial cell made of silicon crystalline cell and 38.8% in the case of a five-junction silicon crystalline cell (Green et al. 2011). However, all the types of performance of photovoltaic modules are influenced by a large number of environmental parameters (air temperature, wind speed, air pollution, the angle of incident irradiation, solar radiation spectrum, ageing, snow, dirt and shadowing) (Hassan et al. 2016; Kazem and Chaichan 2016). One of the parameters that influence the energy conversion in PV modules which can be significant in many regions is accumulated dust (Chaichan et al. 2015). The accumulated dust decreases the conversion efficiency because the dust particles reduce and scatter the intensity of the total radiation incident on the PV modules. It was revealed that the dust accumulation rate depends on several parameters such as airborne particle concentration, weather conditions, particle size distribution or type, density, shape, composition, chemistry, charge and variability in reference to the exposure time (Javed et al. 2017). The dust accumulation rate reported in literature varied 1–۵۰ mg m−۲ day−۱ in Colorado (Boyle et al. 2015) and 150–۳۰۰ mg m−۲ ·day−۱ in Minia, Egypt (Hegazy 2001). In another research work, a dust accumulation rate of 132 mg m−۲ ·day−۱ was reported in Mesa, Arizona (Boppana et al. 2015). The physicochemical properties of deposited dust (Kaldellis and Kapsali 2011), as well as particle size distribution of dust deposited on the surface (Said 1990), have a significant impact on the degradation of PV module performance. The size of deposited solid particles plays a major role in the scattering and absorption of radiation incident on the solar module and causes degradation of PV module efficiency.