Absorber material
The material from which the absorber is made. It is a layer that absorbs solar energy. It is the main part of the collector; the general specs of the device largely depend on its design.
In most modern models, regardless of type, the absorber is made of copper with a special coating. This metal has a high thermal conductivity and effectively transfers heat to the heating medium. And the coating is used to improve the absorption of sunlight, reduce its reflection and, accordingly, achieve good efficiency indicators.
Another option found in solar collectors is aluminium. It is somewhat cheaper than copper and weighs less, but it is inferior to copper in terms of thermal conductivity and performance.
Absorber absorption coef. α
The absorption coefficient of the absorber used in the collector design.
This parameter directly affects the overall efficiency of the absorbing coating and the efficiency of the device as a whole. The absorption coefficient describes how much of the solar energy reaching the absorber is absorbed by it and transferred to the heat carrier. Ideally, this parameter should reach 100%. However, it is extremely difficult and unreasonably expensive to achieve this. Therefore, the absorption coefficient is usually somewhat lower — about 95%; this is more than enough for the efficient operation of the collector. The rest of the energy is reflected as radiation; for more details, see “Absorber emissivity coef ε". Also note here that in the design of tubular collectors, tubes with a special inner coating are often used, which returns the reflected rays to the absorber and increases the actual absorption coefficient.
Absorber emissivity coef. ε
The absorption coefficient of the absorber used in the collector design.
This parameter directly affects the overall efficiency of the absorbing coating and the efficiency of the device as a whole. The absorption coefficient describes how much of the solar energy reaching the absorber is absorbed by it and transferred to the heat carrier. Ideally, this parameter should reach 100%. However, it is extremely difficult and unreasonably expensive to achieve this. Therefore, the absorption coefficient is usually somewhat lower — about 95%; this is more than enough for the efficient operation of the collector. The rest of the energy is reflected as radiation; for more details, see “Absorber emissivity coef ε". Also note here that in the design of tubular collectors, tubes with a special inner coating are often used, which returns the reflected rays to the absorber and increases the actual absorption coefficient.
