Effect of incidence angle on PV soiling loss

Abstract

The effect of light incidence angle is crucial for accurate interpretation of soiling sensor readings and soiling loss data. In this study, the effect of incidence angle on soiling loss is investigated under a solar simulator using artificially and naturally produced soiling samples on different types of glass substrates. It was found that the incidence angle dependence of soiling loss can be described satisfactorily using a two-parameter model, which has one power-law parameter associated with dust morphology and a fraction parameter dependent on the substrate’s angular transmittance. These results are applicable to beam radiation; further research is needed to apply them to field conditions in which diffuse solar radiation is significant. Findings from this study may provide an approach for more accurately calculating PV soiling loss based on optical sensor readings and for more meaningful soiling loss comparison across different locations.