Solar Energy-Thermal Energy Conversion

Dark absorber can absorb the radiation of the sun, which can transform solar energy into thermal energy with good absorption performance and heavy heat loss. Therefore, dark absorber is not satisfactory for absorption of solar energy.

Selective absorber is comparably satisfactory for absorption of solar energy due to its high absorption ratio, low radiation ratio, good absorption performance and small heat loss. It is made of selective absorption material, simply called selective paints. It was proposed in 1940s and reached the applied requirement in 1955. After 1970s, many innovative selective paints were developed for mass-scale production and promotion. Right now, hundreds of selective paints have been developed.

Since 1970s, China has started its research and development of selective paints with results achieved. It has been extensively applied to solar collector with obvious effect.