Numerical investigation of the effect of dust shields on accumulation of dust over PV panels

Abstract

Dust accumulation on photovoltaic panels represents a major challenge for the operation of solar panels especially in the regions known by their high rate of dust and low frequency of rain. The objective of this study is to minimize dust accumulation on PV panels operating street light posts using dust shields. A novel dust shield having the same width of the panel, and subtending an angle of 120° with the panel, is proposed for dust mitigation. Numerical simulations are carried out to evaluate the influence of the dust shield on dust accumulation over the panel’s surface. It is found that using a dust shield decreases the dust deposition rate by more than 44%. Moreover, extending the panel’s surface at the lower edge with an extension plate together with the dust shield decreases the dust deposition rate better than using a dust shield only. Also, the effect of adding an air gap between the shield and the added extension plate is investigated, and it is found that the air gap induces air drafts over the panel’s surface, which acts as an air barrier that obstructs the approach of dust particles to the panel’s surface. These drafts get stronger as the air gap thickness increases, accordingly, less particles deposit on the panel. Finally, it is found that using a dust shield with a length smaller than the panel’s length in addition to an extension plate together and increasing the thickness of the air gap is an effective and efficient solution for dust mitigation, such that the percentage decrease in the dust deposition rate that might be more than 88%.