Investigating the impact of soiling on the performance of various solar cell technologies

One of the main factors challenging the deployment of solar energy technologies in desert-like climates is dust. Most previous studies of soiling have focused on how total PV power output declines with time as dust accumulates. This study takes a different approach by examining how dust affects different cell technologies through the combined analysis of the optical transmittance of the accumulated dust and the spectral response of each cell. Dust was collected on clean glass slides over nine weeks during the summer season (end of June, July, and August) in Bahrain. Four solar cell technologies were considered: two crystalline silicon (c-Si), amorphous silicon (a-Si), copper indium selenide (CIS), and cadmium telluride (CdTe). The short-circuit current (Isc) and open-circuit voltage (Voc) of each cell were calculated for every week using a mathematical model that combines the measured dust optical transmittance with each cell’s spectral response. The results show that dust reduced light transmission to about 50% of the clean-glass value within the first week and to more than 90% by the final week. Among the technologies investigated, crystalline silicon showed the greatest resilience to soiling, while CIS and CdTe experienced a substantial reduction in short circuit current as early as the third week.