Abstract

Dust deposition on photovoltaic modules induces coupled optical and thermal effects that significantly reduce energy yield. This study developed an integrated computational framework combining a temperature-dependent Beer-Lambert optical model with computational fluid dynamics based thermal analysis of soiled photovoltaic modules to quantify performance losses as a function of dust thermophysical properties. Results show that transmittance decreased from 1.0 to 0.852, corresponding to a 14.8% optical loss, while surface temperature increased by 13.3 K under stagnant conditions, producing a thermal penalty of  5.3%. The combined effect yielded a total daily energy loss of 20.1% at standard irradiance. Sensitivity analysis revealed that low-conductivity dust (κ = 0.1 W/mK) and a larger dust layer caused the highest thermal rises, whereas wind speed reduced but did not eliminate insulating effects. Partitioning analysis revealed optical losses being dominant at light dust loading with 70% of total loss at 0.05 kg/m², while thermal losses rose to 45% under heavy loading of 0.20 kg/m². Losses levelled near 22% due to thermal and optical saturation. The study showed that excluding thermal effects in modelling underestimates performance degradation and the coupled model in this study provided an improved model for predicting photovoltaic yield losses that address both optical attenuation and thermal insulation.