The use of thin glass reflectors for solar concentrators

Abstract

Elastically deforming thin glass ( thickness=0.13–0.80 mm ) provides an alternate method of forming a curved glass reflector which can eliminate some of the disadvantages of thicker glass. This paper describes a concept where silvered thin glass is bonded to a steel backing to form a laminate with a reflectance greater than 93%. Subsequent bending of the flat reflector laminate to a concentrating profile produces compressive stresses throughout the glass if the laminate is properly designed. These compressive stresses enhance fracture resistance and the lamination provides protection for the silver. The design of the laminate is outlined for 0.25 and 0.51 mm thickness glass and fabrication procedures are discussed. Thermal/humidity cycling, hail impact, bond strength measurements and reflectance results are presented which demonstrate the performance capabilities of this reflector laminate concept.