Dust cycle, soiling effect and optimum cleaning schedule for PV modules in Iran: A long-term multi-criteria analysis

Mineral dust has a great effect on the performance of solar power plants not only by absorbing and scattering solar radiation, but also due to soiling effects. The aim of the present study is to investigate the characteristics of dust in Iran using the Modern-Era-Retrospective-Analysis for Research and Applications in 2000-2019. In this assessment, radiation effects, dust emission and deposition rate in Iran were investigated from the aspects of seasonal changes and trends. Then, the effect of soiling in a 100 MW power plant in a twenty-year period in different regions of Iran was investigated. Finally, 15 cleaning scenarios were examined from three technical, economic, and environmental perspectives, and the most appropriate scenario was selected in each region of Iran using the multi-criteria decision-making method (MCDM). The evaluation showed the most dust emission rate is occurred in the southwestern Iran. In addition, rainfall has only been able to reduce the soiling effects in the western part of Iran to some extent, but it cannot be a suitable economic solution to reduce this effect. With dust soiling effect, the Levelized cost of energy (LCOE) varies from 100 to 270$/MWh. However, cleaning can reduce LCOE to 50$/MWh and is vital solution to develop solar energy in dusty areas. The results of MCDM also showed that weekly and semi-weekly automatic cleaning are the most suitable periods in Iranian solar plants.