Investigation of the Dust Scaling Behaviour on Solar Photovoltaic Panels

Abstract

Solar photovoltaic (PV) power technology is a promising approach to solve global energy and environmental problems. However, dust accumulation on solar PV panels considerably deteriorates their working performance and power generation. In this study, the appearance and phase, as well as the formation and evolution, of dust particles on PV panels were experimentally analysed in Wuhan, China. In addition, the dust scaling characteristics, and effects of dust pollution on PV panels were investigated. The results show that nano-, micro-, and coarse particles, as well as many pores, are disorderly distributed on PV panels. The phase composition of the dust particles on the PV panels includes SiO2, Al2O3, Fe2O3, CaMg(CO3)2, Ca(OH)2, CaO, and CaCO3. Further, the dust particles on the panels originate primarily from industrial products and urban pollutants, such as sandstone, lime, and dolomite, which are transported from the ground to the PV panel flow field via wind and airflow generated by traffic. Moreover, CaO and Ca(OH)2 react easily with water vapour and carbon dioxide, respectively, in the air to generate CaCO3. With the coupling effects of meteorological and environmental conditions, CaCO3 precipitates and scales on PV panels. An induction period facilitates the transition of the dust particles from a loose state to a scaling state. This period decreases with increasing time, relative humidity, and average daytime temperature. Dust scaling behaviours intensify the dust pollution degree and significantly decrease the transmittance of the PV panels. These findings can provide theoretical guidance for the development of efficient and safe dust removal technologies for PV panels.