Effects of reduced sulphur atmospheres on reflector materials for concentrating solar thermal applications

Highlights: • Sulphurous atmospheres do harm the performance of certain CSP reflectors. • Traditional measurements do not detect almost any reflectance loss after the ageing. • The main degradation pattern in silvered glass reflectors are corrosion spots. • EDS microanalyses reveal the reaction between the H₂S and the silver layer. • Aluminium reflectors do not corrode in the presence of the sulphurous gas. - Abstract: The degradation of reflector materials for concentrating solar thermal applications is analysed. Corrosion of their metallic reflective layer is considered a major problem in facilities which are located near industrial sites, where reduced sulphur gases may be present. Accelerated ageing tests were performed to study the influence of H₂S on the corrosion of two types of silvered glass reflectors and one aluminium reflector. Different degradation patterns were found for silvered glass reflectors, whereas aluminium reflectors did not corrode in the presence of the sulphurous gas. Therefore, industrial pollution caused by this type of gas may decrease the solar collectors' performance.