Quantifying Water Savings in CSP Plants: A Systematic Study of Self-Cleaning Coatings Through Gravimetric Analysis

Water scarcity in arid regions poses a significant challenge for the maintenance of Concentrated Solar Power (CSP) plants, where mirror cleaning consumes substantial resources. This study proposes a systematic methodological framework to bridge the gap between laboratory-scale surface characterization and engineering-scale water consumption. Through a gravimetric approach based on the physical principles of droplet retention (Furmidge theory), the water-saving potential of self-cleaning coatings has been quantified. Experimental results on 100 cm2 specimens demonstrate that hydrophobic coatings can reduce residual water from 0.52 L/m2 to approximately 0.24 L/m2, achieving a water-saving potential of over 50%. The model incorporates a site-specific soiling factor (f_dirt) and was validated using field data from the ENEASHIP pilot plant. This approach provides a promising predictive tool for plant operators to optimize cleaning strategies and reduce operational costs, offering a scalable methodology for the solar thermal industry.