Effect of anti-soiling photocatalytic coating for concentrator photovoltaic module

An anti-soiling layer was coated on the surface of polymethylmethacrylate (PMMA), which is the primary material of Fresnel lenses for concentrator photovoltaics. The layer was prepared by coating the photocatalytic surface layer with modified WO₃ and partially hydrolyzed tetraethyl orthosilicate. When sand was discharged onto the PMMA samples, the mass of adherent sand was more than 0.010 g for the sample without the coating and approximately 0.005 g for the sample with the coating. The electrostatic potential of the sample without the coating increased with increasing amount of incident sand, reaching a maximum value of 0.25 k V. On the other hand, the electrostatic potential of the sample with the coating was suppressed to 0.1 kV. The presence of electrostatic charges on the surface of the samples was a main factor for the adhesion of sand, and it could be suppressed by the anti-soiling photocatalytic layer..