U.S. Department of Energy - Energy Efficiency and Renewable Energy

SunShot Initiative

Cleanable and Hardcoat Coatings for Increased Durability of Silvered Polymeric Mirrors

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3M developed innovative coatings to achieve abrasion resistent polymeric reflectors under the 2007 CSP R&D FOA. This diagram shows the most successful coatings identified by the research team based on the mix of three materials.

3M, under the CSP R&D FOA, is developing optical coatings for solar mirrors that are durable, easily maintained, and more cost-effective.


3M is developing novel optical coatings specifically for application to or integration into silvered polymeric mirrors having poly-methyl-meth-acrylate (PMMA) front surfaces. These coatings offer a durable hardcoat and/or a cleanable surface. In addition, 3M seeks to:

  • Demonstrate manufacturing processes for these novel optical coatings and incorporation onto mirrors
  • Demonstrate performance of coated silvered polymeric mirrors made using these novel optical coatings in field trial
  • Validate the impact of these novel optical coatings on the levelized cost of electricity (LCOE) of concentrating solar power (CSP) system in field trials.


The durability and cleanability, in conjunction with advantages of polymeric mirrors, are expected to contribute to significant capital cost reduction in CSP installations and reduced LCOE relative to current systems based on thick glass mirrors. Improved abrasion resistance and cleanability of the front surface of a silvered polymeric mirror is expected to decrease the rate of reflectance loss and irreversible soiling by 50%, relative to an untreated surface. At the end of this project, 3M intends to produce optical coatings that enable the use of polymeric reflectors, which in turn will enable the use of collector designs requiring much less backing structure to support the reflector.

Publications, Patents, and Awards

At this time, this project does not have published articles, patents, or awards.

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Quarterly Progress Reports

Learn about other DOE competitive awards for concentrating solar power research that are in progress.