Combining dust scaling behaviors of PV panels and water cleaning methods

Abstract

Dust scaling on photovoltaic (PV) panels can significantly decrease power generation efficiency and potentially trigger fire hazards through hot spots. Therefore, understanding the formation process of scale and reasonable cleaning methods is crucial for its practical application and maintenance. This study systematically reviewed the dust scaling process and various water-based cleaning methods to optimize maintenance strategies for enhanced efficiency and safety in PV systems. Soluble and hygroscopic mineral particles absorb dew, forming extensive scale through capillary action. Biological and industrial dusts promote the formation of hard scales. Typical scale formations include approximate laminar, localized accumulation, island-like, and gully laminar scales. Based on weekly PV efficiency declines attributed to dust accumulation, Asia is the most severe (7.84 %), followed by Africa (3.03 %), Oceania (2.40 %), South America (1.90 %), North America (1.32 %) and Europe (1.21 %). In different climatic conditions, the western part of Asia, the Gulf region, and northern Africa exhibit the most significant potential for scale accumulation. Pressurized water cleaning improves power generation efficiency by an average of 10.4 %, and the average water usage is 2.1 L/m², with a water recovery rate of 55–80 %. Optimal cleaning frequencies were determined to be seven days for 37 % of cases and 7–30 days for 44 %. It is recommended that areas most affected by dust be cleaned weekly and at least monthly for other areas susceptible to dust. This study provides practical guidance for PV maintenance, supporting the global expansion of clean energy through improved efficiency and safety.