High-temperature solar absorbers
Optically selective composite materials for high-temperature solar absorbers in solar thermal electricity generation, will lead to higher conversion efficiencies.
Solar thermal electricity generation involves the conversion of solar radiation into heat, and then the heat into electricity via a turbine. Conversion efficiency increases with temperature, provided that the high-temperature absorber does not lose the absorbed energy before it reaches the turbine. We are developing selective coatings for solar absorbers capable of efficiently absorbing solar radiation, while at the same time minimising the emission of thermal radiation to the environment. Such selective coatings exist for moderate temperatures of up to 500ºC, but advanced solar thermal plants with higher efficiencies will require similar capabilities at temperatures exceeding 600°C. These coatings are based on a “cermet” composite structure, a ceramic layer with embedded metallic nano-particles. Our research includes selecting the materials for both components of the composite, defining the size, density and arrangement of the particles, characterising the resulting optical, thermal and mechanical properties, and validating the stability of the coating at high operating temperatures.
Collaboration: D. Mandler, S. Magdassi (HU), D. Feuermann (BGU), B. Steinberg (TAU)
Support: Israel Ministry of Science