Influence of irradiance incidence angle and installation configuration on the deposition of dust and dust-shading of a photovoltaic array

Highlights: Soiling on different PV configurations is predicted using CFD simulations. Total shading computed from deposited dust and varying irradiance incidence angles. Hourly energy computed on soiled PV with varying tilt, azimuth and incidence angle. Optimisation and empirical modelling is done for soiling minimization. A model was developed to predict the soiling due to dust concentrations. The influence of installation configuration and the angle of incidence on the total shading of a soiled photovoltaic collector was investigated. A model to determine the total shaded area on concentrated dust particles on a photovoltaic surface was also developed. Computational Fluid Dynamics (CFD) was employed to ascertain dust accumulation on each installation configuration. The SST k-ω turbulence model was used together with the Discrete Phase Model (DPM) for the respective computation of the air fluid and dust particle motion. Annual simulation of daily total shading and the energy generated was performed. The results showed that energy generated when both direct and indirect shading was considered was less by 2.49% to the generally expected energy without considering the shadow effect of dust particles. The minimising of the shading effects using Response Surface Methodology gave a range of tilt angles from 15.84° to 17.69° at 180° to 189.9° azimuth angles as the optimum configurations which can generate up to 38.62 kWh for a 5 kW hypothetical solar system. The shading effect of dust particles was modelled using a 2^nd order polynomial with tilt and orientation as the parameters and the model had good accuracy with a coefficient of determination of 0.9811.