Laminated Solar Thin Glass Mirror Solution for Cost Effective CSP Systems

Within the frame of an R&D project, toughTrough GmbH (TT), Bremen, in a joint initiative with its partners AGC Solar (AGC) and Bayer MaterialScience (Bayer MS), has developed, tested and optimized a light-weight mirror solution for CSP mirror systems including the overall collector and drive system. The mirror system is particularly distinguished by its light-weight composite structure that leads to reduced loads and moments due to an integrated wind tunnel optimization process. As a result, the thin glass mirrors are resistant against environmental impacts such as humidity, wind, hailstorm and abrasion. Also, they have successfully passed corrosion tests as well as general and specific product safety tests. The integrated structure of the mirrors provides higher stiffness and efficiency and is individually adaptable to the specific conditions at the operation site. The application of AGC Solar Mirror Thin glassas a reflective front layer guarantees a higher grade of reflectivity (> 96 %). The composite structure of the light-weight mirror allows a significant weight reduction of the supporting structure and foundation. Its high stiffness guarantees higher performance with lower focal and slope deviation within the operational parameter range and 3D optical geometry/focal length and the integrated mechanical interfaces are individually adaptable. The fail-safe composite mirror enables easy logistics, handling and integration and consequently a reduction of field set-up time. The higher reflectivity and the lower slope error lead to about 4-7 % higher field efficiencies compared to standard facets with 4 mm mirrors as calculations for 5 MWel, 30 MWel and 150 MWel power plants, performed by DLR, have shown. A state-of-the-art mass production process which is used in the automotive field assures high product quality and low specific costs.