The Sunstrip absorber has been developed in cooperation with the Ångström Laboratory in Uppsala and other leading universities within the area. Our absorbers and heat exchangers, used by us and other leading solar energy companies and construction companies around the world, all use a selective, high performance and durable thin film surface. The surface must be able to work in different climate zones, weather conditions and resist impact from external forces showing long term durability.
Asoluna’s absorbers show a superior performance during tests by independent test institutions and are with the certified Solar Keymark certification in all markets. The absorbers that are used in solar thermal collectors can be likened to the engine in a car. To be able to absorb a maximum of the solar energy, the absorber needs to have a surface with high optical efficiency. It must be able to absorb a maximum visible light, exchange that to heat and then to keep a maximum of the heat. Our performance shows 96-98% in absorption capability while the emission or losses are 3-5%. This is very close to the theoretically limit of performance.
The surface of the absorber contains three nano meters thin surfaces. The absorbing surfaces are so thin that they are transparent to heat radiation while they include components that absorb the light. The next surface, 50 nano meters thick, is an anti-reflection surface to minimize light scattering. The thin film surfaces are applied to a blank plate in aluminium, and together create the optical efficiency.
The thin film surface requires an advanced high-tech production process. The surface is produced by using a patented production technology, magnetron sputtering technique. The process is performed in a high vacuum environment with high electrical voltage. A metal plasma is produced for coating the absorber in three layers of nano thin surfaces.