This project addresses the need to further develop self-cleaning reflector coatings for solar collectors. When solar collectors get dirty, their ability to collect sunlight is diminished. Through field demonstrations at CSP test sites, researchers are investigating the efficacy and durability of superhydrophobic coatings that can provide anti-soiling capabilities for trough and heliostat mirrors. In order for the coating to be cost effective, the team is developing a low-cost, industry-standard spray coat technique to apply the anti-soiling coating.
The research team is developing glass-coating techniques to deposit the multilayer coating over large areas. The team is working to understand the interactions between all of the spray coat processing conditions and how they can achieve the best optical and anti-soiling properties at high throughput and low cost. This will lead to a semi-automated spraying process that can continually replicate the coatings. Eventually, the spray process will be transitioned to an automated coating application system at a mirror production or glass coating facility. Researchers will deploy test arrays that have been coated to evaluate its performance under a variety of environmental conditions.
Mirrors coated using the newly developed laboratory spray system aim to have 50% less dust accumulation than uncoated mirrors, reducing costs associated with frequent mirror washing. By using this anti-soiling coating, solar collectors will stay cleaner longer, improving mirror reflectivity to maintain the maximum possible power output of CSP systems and lower the levelized cost of electricity by up to two cents per kilowatt hour.