Power loss due to soiling on photovoltaic module with and without anti-soiling coating at different angle of incidence

This paper evaluates the electrical performance of photovoltaic (PV) modules with and without anti-soiling coating at different incidence angles and layers of soiling. Two test coupons were evaluated, one of which was uncoated and the other was coated with an anti-soiling coating. Preliminary examinations for the presence of inherent defects were carried out using Ultraviolet Fluorescence and Electroluminescence imaging techniques. The coupons were then exposed to different layers of soil, accumulated naturally, using an outdoor soiling setup. The short-circuit current (I-SC) was measured at different angle of incidence (AOI) before and after the deposition of soil. The maximum drop in the I-SC was recorded to be 8.79% and 5.47% at 60 degrees AOI for clean uncoated and coated coupons respectively. The I-SC of soiled modules also depicted a similar downward trend in the I-SC. Further, it was found under soiled conditions, the critical AOI for the coated coupon was found to be enhanced by 5-15 degrees in comparison to the uncoated one. Henceforth, the significant reduction in soiling loss would ultimately result in the improved efficiency of the module.