The preparation and testing of spectrally selective paints on different substrates for solar absorbers

In this paper the preparation and testing of spectrally selective paint coatings for absorbers in flat-plate solar collectors are shown. This represents the most inexpensive way of preparing such an absorber. Basic properties of coatings prepared on aluminum, copper and stainless steel substrates are described together with the stability of the painted substrate. To calculate the performance of the solar collector with a painted absorber, a dynamic multi-node model was applied. It considers the main components and heat transfer fluxes of a flat-plate solar collector.