Concentrating solar power (CSP) plants are often located near industrial areas typically affected by high concentration of sulfur
dioxide (SO2). This paper is focused on the influence of acid atmospheres of SO2 on the durability of solar reflectors, under
accelerated aging conditions. A whole test campaign was designed and performed. All types of commercial solar reflectors were
included. The accelerated aging tests consisted in applying up to 50 cycles, according to ISO Standard 6988. To quantify the
optical degradation, reflectance was measured and a visual assess was done. After exposing the samples to the acid rain
atmospheres, the deterioration and reflectance drop was smaller in thick glass mirrors than in the case of thin glass, aluminum
and polymer mirrors. The anodized aluminum mirrors showed overall staining and intergranular corrosion, while coated
aluminum mirrors did not show any degradation. Although no major reflectance losses were detected in polymer mirrors, a
significant degradation, such as pitting corrosion on the reflector and damaged edges, was noticed.