Modelling of optical durability of enhanced aluminum solar reflectors

In order to reduce electricity generation costs of concentrating solar power (CSP) technologies, new low-cost reflector materials are being developed. These materials need to withstand harsh outdoor conditions without a significant loss in specular reflectance. In this work, samples of enhanced anodized aluminum reflectors protected by a sol–gel coating that have been exposed at different weathering sites were analyzed with an innovative specular reflectometer in order to monitor corrosion and scattering caused by surface roughness. A model to estimate the specular reflectance as a function of exposure conditions at different weathering sites has been developed.

► The degradation mechanisms of enhanced first‐surface aluminum reflectors are analyzed.
► The influence of degradation on the specular reflectance of the mirror is measured.
► A model to predict the specular reflectance as a function of time has been developed.
► The estimated reflectance loss after 10 years of weathering at four sites is presented.