Development of Black and Red Absorber Coatings for Solar Thermal Collectors

Abstract

Recent developments in solar-thermal energy conversion systems are focused on obtaining solar selective absorber materials with high selectivity and durability and asked for cost-effective and environmentally friendly synthesis techniques (e.g. sol-gel and chemical spray pyrolysis). In this context, the paper gives an overview on the state-of-the-art of the research reported till now on different types of black and colored absorber coatings for solar thermal col-lectors obtained world-wide. Some results obtained by the group active in the R&D Centre Renewable Energy Systems and Recycling are also reported and they are related to the development and optimization of black (NiS x) and red (Fe 2 O 3) absorber coatings, as active components in solar thermal collectors. These results are considered promising for novel, market-competitive solar-thermal collectors, with increased architectural acceptance, for facades integration in Nearly Zero Energy Buildings.