Development and mean life of aluminum first-surface mirrors for solar energy applications

Aluminum solar mirrors are an alternative for solar concentrators. This paper presents the first aluminum-surface solar mirrors, which, after 12 years of exposure to the aggressive weather conditions of Mexico City, have a reflectance decrease of only 3% (from 0.85 to 0.82), with only small scratches on the SiO2 layer. Furthermore, two alternatives are presented for solar aluminum mirrors: mirrors with integrated first and second surfaces and first-surface compound mirrors. Each mirror and its fabrication are described, along with their weather tests. The aluminum first-surface solar mirror lasts for at least 12 years, and is a good alternative material for parabolic troughs, heliostats, CPC, Fresnel technology and dish concentrators.