Dust Storm Simulation for Accelerated Life Testing of Solar Collector Mirrors

Abstract

A dust storm simulation chamber has been designed based on worst-case conditions to simulate the effects of blowing dust and sand on candidate solar concentrator materials. After evaluation with common glass mirrors, the system was used to simulate field exposure of Carolina glass mirrors in the West Texas environment in terms of loss of reflectivity. System calibration was achieved by comparing actual exposure data over a three-year period to results obtained in the simulation chamber. It was found that a twenty-year service life can be simulated by 80 hrs. exposure in the dust storm chamber. Degradation of the Carolina glass mirrors has been shown to be primarily dependent on momentum transport to and kinetic energy deposition on the mirror surface during dust storms: annual reflectivity losses of 2.4 percent and 1.4 percent may be expected, respectively, from dust storm and the sum of all other effects.