Structural and physicochemical properties of dust collected on PV panels surfaces and their potential influence on these solar modules efficiency in Dakar, Senegal, West Africa

Abstract Two dust samples were collected from the same solar panels on June, 2017 in Dakar. The first was sent to Ithemba Labs (South Africa) and the second to Lincon Nebraska University (USA) for structural and physical properties study. This work aims to evaluate the dust impact on PV efficiency. The study shows that these particles have a non-spherical shape with sizes between 0 and 50 μm. However, most of them have a size about 2 μm. Elemental composition based on Energy Dispersive X-ray microanalysis indicates that dust is dominated by elements such as O, Na, Mg, Al, Si, Cl, K, Ca, Ti, Mn and Fe. Some elements such as P, S, Zn, Sr, Zr and Cr are minority or in traces form. The analysis shows that this African dust is a mixture of different chemical compounds with a predominant phase consisting of SiO2 type quartz about 73.8% of the total and the second phase is certainly calcite(CaCO3) representing 13.6% of the collected particles. The rest (12.6%) is presumably a mixture of Iron Oxide Chloride (FeOCl), Mantienneite (Al2FeH33K0.5Mg3O34P4Ti) and Kaersutite (Al2Ca2Mg6NaO24Si6). Finally, the diffuse reflectance spectroscopy (DRS) shows that these particles reflect more than 70% of the irradiation reaching the PV panels surface.