LAUSR

Abstract The Sultanate of Oman, similar to other GCC countries, is affected by the fluctuation of oil prices, which led the decision-makers in this country to move towards renewable energy and particularly the establishment of photovoltaic (PV) solar power plants. This step requires a thorough study before spending millions of dollars to build such power plants. Since dust is one of the main problems of PV in the GCC countries, this study investigates the influence of certain weather factors such as wind speed, relative humidity on dust accumulation and the effect of the cleaning method applied to each city separately. After a full year of observation and data collection on climatic conditions and the output of the six systems installed and used in this study, it is found that the cities of Liwa and Sohar, followed by Muscat, exhibit the highest percentage of dust and contaminants. The most prominent pollutants are the particulate matters (PM) from the chimneys of the power plants, and smelters in the industrial city of Sohar. Also, the movement of a considerable number of vehicles in Muscat caused a rise in the concentration of PM deposited on PV cells. For the other three cities (Al-Khabourh, Suwaiq, and Shinas), they are far from any industrial zone, and because of reduced traffic, the percentage of accumulation of dust and pollution of PV cells was limited. Nine available methods have been used to clean the PV cells after the dust accumulated for one month. From these methods, it is found that the use of water is sufficient to wash the PV cells in the cities of Al-Khaburah, Shinas, and Al-Suwaiq, but the effect of cleaning is more reduced on Sohar, Liwa, and Muscat. Because of PM and many chemical compounds, the use of a sodium solution was the best option in cleaning the PV cells of these three cities. It was noted that the loss of solar cell productivity decreases during the rainy season, which acts as a natural cleaner for the PV. The study also found that dew in the cities studied before sunrise causes the interaction of some salts of sodium, magnesium, and calcium and builds a layer of cohesive salts, which are difficult to clean.