Development of a test method for the investigation of the abrasive effect of sand particles on components of solar energy systems

Currently, there is no appropriate, standardized, accelerated test method to investigate the abrasion resistance of components of solar energy systems under sand storm conditions. Therefore, this paper deals with the development of a test method for the investigation of the sand abrasion mechanism on selected solar technical components. For this purpose, first, the mechanisms of surface damage induced by trickling sand are experimentally investigated. The designed method based on ASTM D968-05 enables to describe the sand abrasion mechanisms on aluminum reflectors and solar glasses. Also, differences in the abrasion resistance of the samples are revealed. In addition to changes in their optical properties, an increased surface roughness can be determined. Depending on the impact angle, hardness of the exposed material, sand trickling mass and sand concentration, different surface changes are caused. The concentrated particle stream led to strong abrasive damage on the reflector surfaces, whereas glasses show a better abrasion resistance to trickling sand because of their higher hardness. The second, horizontal test method designed according to the sandblasting principle allows a more realistic investigation of the sand abrasion process on samples under strong wind conditions. The low, sand-laden air flow causes less abrasive damage on the reflector surfaces.