Contemporary considerations of the utility of self-cleaning coatings for solar power installations-The SolarSkin system

Abstract

Soiling of conventional Photovoltaic (PV) modules and Concentrated Solar Power (CSP) mirrors significantly affects the efficiency of the system. Although there are several soiling mitigation strategies, none of them has been widely adopted, since effectiveness in real field conditions is often disputed. Anti-soiling coatings are perhaps the most promising solution for solar power projects since they combine low cost and effectiveness. These are broadly categorized into hydrophilic and hydrophobic. Hydrophilic coatings perform better in arid climates, whereas hydrophobic coatings have a wider spectrum of functionality. Most of them however suffer from various drawbacks, such as poor durability and transmittance which restrict the extent of benefits. In addition, there are only a few reliable technologies that can be retrofitted to existing installations. Predicting the efficiency of a given anti-soiling coating in a specific plant is difficult, therefore, the objective of this work was to identify those parameters that are critical to their performance in real outdoor conditions. Focus was given to the drawbacks of current hydrophobic coating systems and the requirements that a modern anti-soiling coating should satisfy in order to be implemented as an effective after-market solution to degraded solar systems. A prominent example of cutting-edge, high-performing self-cleaning technology, i.e. the SolarSkin system developed by BFP Advanced Technologies, is additionally presented. The latter can renovate deteriorated solar collectors, increase the energy yield of the system, and protect it from weathering effects over its expected operational lifecycle. Potential increment of the system’s efficacy as well as maintenance savings are also briefly discussed.