Recent progress of soiling impact on solar panels and its mitigation strategies: A review

Global warming has become a serious concern due to the increased consumption of fossil fuels. Therefore, green energies have received extensive attention. Among all renewable energies, solar energy is one of the most accessible sources of energy that can be used in the electrical sector. However, it is a well-known fact that solar panels, the main transformers of solar energy into electricity, experience a decrease in performance due to soiling. Various methodologies are available for mitigating soiling losses on solar panels, including traditional approaches like water-based cleansing and robotic arms. However, these conventional methods are increasingly avoided due to drawbacks and the lack of water resources. Alternative strategies involve using advanced thin films with transparent conductive and anti-soiling properties. While transparent conductive films are active and augment electrical fields to repel dust particles through electrostatic forces, anti-soiling films are passive and reduce adhesion forces between dust particles and solar cell surfaces. The present study aims to fill the gap in the existing literature by providing a comprehensive review of passive methods for reducing dust on solar panels, which has been lacking until now. The methodologies and the test methods used in these approaches such as self-cleaning, dust repulsion, and mechanical abrasion tests are illustrated, offering researchers a thorough overview of previous studies. Finally, additional research topics and future perspectives for enhancing the key properties of these surfaces such as transparency, durability, thermal shock resistance, ease of coating process, affordability, and nontoxicity are discussed.