via Sun & Wind Energy
Black Instead of Blue?
by Joachim Berner
Blue PVD absorber coatings have prevailed so far on collectors. Given the domination of just one manufacturer, new players are developing alternatives. Black coatings could once again gain in importance.
What we are talking about is thin: wafer thin. The coating on the collector is just a few nanometres thick, and ensures that as much sunlight as possible is converted into heat. Most collectors in use today are coated with highly selective layers, which are applied in a vacuum vapour deposition process. In the market overview of flat-plate collectors on the SUN & WIND ENERGY homepage, 93 % of the 250 collector models receive an absorber with such a coating.