Influence of environmental stresses on the performance of new selective coatings for unglazed solar thermal collectors
New types of solar selective absorber coatings developed on stainless steel substrate for unglazed solar collectors were analysed in terms of performance and durability at SPF Institute for Solar Technology. Indoor and outdoor tests were being performed on small-scale samples (5x5 mm2), absorber prototypes (250x250 mm2) and full size absorbers (870x2370 mm2). No significant visible degradation has been observed at the end of the testing procedure. The performance and durability of a full size absorber coated with a new selective coating is currently under investigations.