More heat than light
The absorber plates in our solar collectors are designed to absorb more of the sun’s energy and radiate less back to the environment as heat. To achieve this they undergo a two-stage electro-plating process. They are first plated with a layer of bright nickel and then re-treated with an over-coat of black chrome. This creates a ‘spectrally-selective surface’ that absorbs more solar radiation and re-emits less thermal energy. The underlying mechanisms are relatively simple. In the short wavelength part of the spectrum, the absorber behaves like a black surface and soaks up most of the sun’s energy. In the long wave length part of the spectrum, the absorber behaves like a silver surface and re-radiates little of its heat.
Envirosun black chrome absorbers are amongst the most efficient solar selective coating available and deliver performance gains about 20% above those available from non-selective treatments.