As Much Hot Water As Your Need Or The Sun In Trap

February 13, 2006

A unique solar collector was developed by specialists of the Moscow “ALTEN” company under the guidance of Boris Kazandzhan, Professor, Doctor of Science (Engineering), Moscow Power Engineering Institute. Originality of the novelty lies in its extremely high efficiency. The collector not only manages to entrap the heat of solar beams falling on its surface, but also to utilize it to a great extent for direct purpose – for water heating.

Evidently, the idea of water heating in sunlight is not at all new. Water barrels painted black are installed on self-made showers perhaps at every country plots, allowing their owners to take a warm shower in summer. Alas, even in the hottest day, the temperature in the barrel is not too high, and there is no means for warming the house by radiators with the water heated in such an old-fashioned way.

The problem is that it is very difficult to catch solar energy and then to retain it. Habitual objects: a water barrel or a bench at the sunny side near the pond in the park do catch visible light energy and become warm – and immediately give a major part of this energy back into the ambient space, mainly in the form of infra-red radiation and convection.

To increase efficiency of absorption of solar energy and to reduce loss of heat, a special selective multi-layer coating based on titanium carbide is used. On the outside, it is dark as it should be to absorb light well. But its peculiarity is that having become warm, the coating almost does not radiate thermal energy. Thus, the coating allows to entrap solar energy in the visible and near infra-red spectral region where more than 90 percent of solar energy is concentrated, and almost not to irradiate energy into the spectral regions corresponding to radiation of heat. The heat entrapped in such a way is collected by water that flows along copper tubes embedded into aluminium shapes covered by a selective coating and forming a so-called absorber. Instead of water, however, some other heat carrier may be used, but water is the cheapest of all.

To protect the reserved heat from being blown away by wind, in other words – to reduce loss of heat into the environment due to convection, the absorbers are inserted into special plastic casings. The casings are made of polycarbonate, which is not solid but cellular. The cells are hollow, that is why the air inside them is motionless, thus allowing to preserve the heat of water warmed by the Sun no worse than a good down-bed does. As for polycarbonate, it passes the light through very well, it does not get warm and does not cast shadow, so it does not impede the work.

As a result, during a sunny day, one collector of 2 square meters in area can heat approximately 150 liters of water up to the temperature of 60 to 70 degrees C. If necessary, water can be heated up to the boiling point. Several collectors can provide for hot water-supply and heating of a small cottage. Evidently, in the moderate climate, for instance, in the Moscow Region, it makes sense only during the “long” summer season since early spring till late autumn. In wintertime, one cannot survive only on solar heat, be the efficiency of such system even one hundred percent. However, in the mild European climate the system would serve all year round, to say nothing about warm areas. In near future, the first house with such heating will appear in the town of Sochi. Its front will be decorated with the ALTEN solar collector boards. The house will be provided with hot water the whole year round.

Source: Informnauka Agency

Explore further: Earth breaks heat record in 2016 for third year in a row

Related Stories

Astronomers search for signs of life on Wolf 1061 exoplanet

January 19, 2017

Is there anybody out there? The question of whether Earthlings are alone in the universe has puzzled everyone from biologists and physicists to philosophers and filmmakers. It's also the driving force behind San Francisco ...

Storing thermal solar energy from summer to winter

January 11, 2017

Can thermal solar energy be stored until wintertime? Within a European research consortium Empa scientists and their colleagues have spent four years studying this question by pitting three different techniques against each ...

Recommended for you

Freeze-dried food and 1 bathroom: 6 simulate Mars in dome

January 20, 2017

Crammed into a dome with one bathroom, six scientists will spend eight months munching on mostly freeze-dried foods—with a rare treat of Spam—and have only their small sleeping quarters to retreat to for solace.

Scientists develop first catalysed reaction using iron salts

January 20, 2017

Scientists at the University of Huddersfield have developed a new chemical reaction that is catalysed using simple iron salts – an inexpensive, abundant and sustainable alternative to costlier and scarcer metals. The research ...

Image: Wavemaker moon Daphnis

January 20, 2017

The wavemaker moon, Daphnis, is featured in this view, taken as NASA's Cassini spacecraft made one of its ring-grazing passes over the outer edges of Saturn's rings on Jan. 16, 2017. This is the closest view of the small ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

codesuidae
not rated yet Jun 11, 2009
Interesting system. I wonder if the multi-layer coating is something that can or could in the near future be applied to various objects by consumers, such as by painting. Such a coating could be useful in many passive heating situations.

But is the winter sunlight in the Moscow Region such that even a larger collection area cannot generate sufficient heat?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.