Reflector and Absorber materials for Solar Heat collection

SOLAR

ABSORBER

SOLAR ABSORBER

Solar thermal collectors use the power of the sun to provide heat for space heating and hot water -- for free, reliably, and without an environmental impact.
The heart of flat-plate and evacuated-tube collectors is the absorber.
It takes up the energy in sunlight and converts it into heat. The more efficient the absorber, the greater the collector's output.

With its highly selective blue TiNOX energy absorbers, Almeco sets industry standards.
These products absorb 95% of incident sunlight.
At the same time, they only lose some 4% of heat radiation, so that around 90% of the solar energy can be used as heat.

In this way, manufacturers of flat-plate and evacuated-tube collectors can ensure the greatest quality and maximum yield for their customers. Almeco applies its highly selective absorber layers both to aluminum and copper substrates in a high-tech coating process.
Collector manufacturers are then able to offer a wide range of high-quality products with TiNOX energy.
No other company in the world has as much experience in the production of highly selective absorbers; after all, TiNOX invented this technology in the mid-1990s and has continued to further develop it since.

All TiNOX energy products are made in Germany on modern production lines in Munich and Bernburg (Saxony-Anhalt). Almeco offers a 10-year guarantee for its TiNOX energy products. A number of renowned testing institutes have confirmed the high quality of TiNOX energy absorber's with their findings.
One part of these inspections was the "task X" test, which simulates the effect of years of temperature fluctuations and exposure to the environment on the absorber's selected layers.
Absorbers that pass this test will still provide 95% of their original output even after 25 years.

TiNOX energy has the Task X certificate from the following institutes:

Fraunhofer Institute for Solar Energy Systems, Freiburg (ISE)
Institute of Solar Technology, Rapperswill College (SPF)

Almeco GmbH fulfills the quality standards required for compliance with DIN EN ISO 9001:2000; Environmental Management StandardISO 14001 and Occupational Health and Safety management standard OHSAS 18001.

COATING

TECHNOLOGY

COATING TECHNOLOGY

TiNOX is an energy trap.
Highly selective blue TiNOX energy absorber coatings take up a lot of energy -- some 95% of incident solar radiation -- and convert it into heat energy.
Conventional absorbers lose a large part of that energy as heat radiation. In contrast, TiNOX energy coatings have an extremely low thermal emissivity of less than 4% in the infrared range to prevent such heat losses.
Once the energy has been converted into heat, it stays trapped within the TiNOX absorber.

The high performance of the absorber layer therefore requires the greatest possible degree of absorption within the solar radiation range and the lowest possible degree of emissivity in the heat radiation range.
TiNOX energy fulfils this requirement ideally:
Solar absorption α= 95%
Thermal emissivity ε < 4%

Both black surfaces and highly selective TiNOX energy products absorb 95 % of incident solar radiation. But black surfaces emit a large part of that energy unused as heat radiation; 45% of the energy is lost. The overall yield of collectors with black coatings is therefore below 50%.

TiNOX energy absorbs 95% of incident solar radiation and converts it into heat.
Like an "energy trap," highly selective blue TiNOX coatings only lose 4% of the captured solar energy as heat radiation.
Around 90% of the energy in sunlight can therefore be used as heat. TiNOX energy absorbers very efficiently take up solar radiation energy, but they only give off little heat radiation.
The trick is to use solar radiation energy at its wavelength below 2.5 µm, while not giving off heat at the cutoff point above 2.5 µm, the characteristic wavelength range for heat radiation from a 100°C surface (maximum operational temperature of a hot water collector).
In other words, our absorbers are capable of reacting differently to wavelengths above and below 2.5 µm; they are selective.
This ability clearly reduces heat radiation losses below the level of a black surface.

The blue surface shows how well TiNOX energy absorbs solar radiation. The pale red area represents heat radiation emissions from a black, non-selective coating. The low heat radiation emissions of TiNOX energy are dark red in contrast. The blue curve shows the reflexion response of TiNOX energy.
In the range of solar radiation, reflection is very low because the absorber is designed to take up as much energy as possible. In comparison, the coating reflects infrared light very well, resulting in very low heat radiation emissions.
After all, as much energy as possible is to remain within the absorber.

Why is TiNOX blue?

TiNOX energy layers get their colour from the multiple reflections of incident light in the top quartz layer.
The light is reflected in the transparent top quartz layer until most of it has been absorbed by the absorber layer.
Only a small part of the spectrum -- the blue part -- manages to leave the quartz layer, producing TiNOX blue’s unique colour. The colour is a pure spectrum of light characteristic of the high-quality antireflection layer.