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PPG, under the Baseload CSP FOA, produced a durable first-surface mirror with improved optical performance and geometry design to reduce the unit cost of the reflector subcomponent in a concentrating solar power (CSP) application.


PPG Industries created an ultra-large, front-surface glass mirror with an inorganic protective hardcoat. This approach worked toward reduced operation and maintenance costs and a lower overall unit cost of the reflector assembly. Moving to a larger-sized glass reflector also reduced manufacturing costs because fewer mirrors are needed. The project aimed to achieve an estimated levelized cost of electricity (LCOE) of less than $0.08/kWh.

Schematic cross section of a first surface mirror.


LS3-sized mirrors use only 55%–65% of the available capacity of existing glass coating equipment. PPG pioneered a design that:

  • Represents a size increase of 2.5 times more than current mirrors
  • Uses a first-surface mirror as opposed to a second-surface mirror
  • Adds a proposed alumina hardcoat to eliminate the passage of light through the glass material while also providing durability and anti-soiling properties
  • Achieves a reflectivity of 97%.


  • The design and feasibility of the first surface mirror concept and the potential for durable topcoat were demonstrated. A solar weighted reflectance of 90.6% (+/-0.6) was achieved and a pathway towards 97% identified
  • A potential of 1% reduction in soiling was demonstrated
  • The design and feasibility of the large area mirror reflector assembly was completed. A mirror support structure was designed and analyzed. Estimated material cost and fabrication and installation cost of $51/m2 and $106/m2 were respectively obtained
  • The LCOE computations obtained a cost of $0.122/kWh and a capacity factor of 76.4%
  • Absorption at silver/dielectric interface was identified as a major technical barrier to achieving high reflectance performance

Final Report

McCamy, James W., Kwaku Koram, and Brian F. Kornish. Next-Generation Low-Cost Reflector. No. DE-EE0003586. PPG Industries, Inc-Glass R&D, 2013. DOI: 10.2172/1080364 

Publications, Patents, and Awards

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

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