Impacts of soiling on solar panel performance and state-of-the-art effective cleaning methods: A recent review

The performance of solar panels in outdoor conditions is a catching-research issue these days, especially in the context of soiling. Soiling reduces the solar panel's output and results in thermal stresses which decrease the effective life of the device. In this study, the soiling of Photovoltaic (PV) modules and various cleaning methods adopted have been discussed. This review covers background research and recent findings till 2024 on soiling and cleaning of solar panels. Various parameters affecting solar PV soiling such as humidity, temperature, soil composition, etc. have been analyzed in detail. To mitigate soiling various cleaning methods have been adopted. The conventional cleaning methods include water cleaning, brush cleaning, and wiper cleaning while advanced cleaning methods include robotic cleaning, anti-soiling coatings, electrostatic cleaning, and Electrodynamic System for cleaning, etc. This literature study aims to highlight the pathways to reduce soiling and to propose various cleaning methods that are effective in different scenarios by identifying the research gaps in current literature and by performing comparative analysis of state-of-the-art cleaning methods. Moreover, this study considers the issues associated with different cleaning methods and recommendations that may be helpful in designing future cleaning devices for solar PV systems.