Experimental investigation of the soiling effect on the PV systems performance and the cleaning intervals in Oman

Abstract

The trend toward diminishing dependence on fossil fuels as an energy source has become a government obsession, resulting in the acceptance of renewable energy as an alternative green energy source. Photovoltaic energy is considered the most viable renewable energy source in the MENA region due to the high solar irradiation level and the number of clear sky days during the year. However, environmental factors such as dust limit the optimum utilization of the source. In this paper, the effect of the accumulated dust on the Photovoltaic module surface has been studied for six months in Oman's weather conditions to suggest an economical cleaning interval. The experiment was conducted on a 5.85 kW grid-tie ground mount system with two strings of 9 modules in series. Two manual cleaning intervals have been applied on each string to observe the effect of the dust on the PV system performance. The results show that the dust accumulation reduced the PV modules' current performance by up to 28 %, with the average current output of the uncleaned string measured at 4.1 A compared to 5.6 A from the cleaned string. Based on the study results, the recommended economic interval in Oman is 8–12 cycles annually, and it is expected to increase in the summer compared to the winter season. This work offers valuable insight to investors, consultants, PV plant O&M companies, PV engineers, and researchers offering prosecutable strategies for optimizing PV system efficiency in Oman.