Air pollution and soiling implications for solar photovoltaic power generation: A comprehensive review

Solar photovoltaic (PV) is a promising and highly cost-competitive technology for sustainable power supply, enjoying a continuous global installation growth supported by the encouraging policies and commercial markets. However, air pollution and soiling of PV modules prevail worldwide, potentially casting a shadow on solar PV power generation. This study presents a comprehensive review of the documented impact of air pollution and PV soiling on solar resources and techno-economic performances of PV systems. Both air pollution attenuation and soiling could significantly reduce the solar PV power generation globally, and soiling losses contribute to most of the total power reduction in most regions except in high-polluted areas. In addition, considering the natural soiling processes, the influencing parameters of soiling such as environmental and configurational factors and their correlation to dust deposition on PV surface are discussed. Furthermore, this study introduces the impact of air pollution elimination on surface solar radiation and solar PV power generation. Given the current novel coronavirus disease 2019 (COVID-19) pandemic, studies related to its effects on the solar PV sector are discussed in the present review. The reported soiling mitigation approaches and technologies are systematically compared. Finally, the current research challenges are stated, and suggestions for future works in improving the penetration of solar PV applications are provided to help promote solar power generation towards carbon neutrality all over the world.