One of the perspective directions of use of solar energy are heating and hot water supply. In this question the potential of solar energy is rather high, however transition to such heating system is accompanied by considerable financial expenses.
In a presage of the coming deficiency of energy carriers the mankind looks for alternative ways of production of energy. The most perspective is the solar power which is actively developing since the beginning of the XX century at the moment. One of useful effects of sunlight is its thermal radiation, using which, it is possible to move heat in premises, avoiding thus application of traditional heating systems.
As collect solar energy
Collecting and transformation of energy of the sun happens at the expense of special devices - solar collectors. They represent the flat or curved panel in which the capillary channels which are passing through itself the heat exchanger as which liquid with very low temperature of freezing is usually used are located. The heated heat exchanger circulates on primary thermal contour, giving heat or by means of thermodynamic process of evaporation and condensation, or a natural way. In the first case the efficiency of installation increases many times while the second method of transfer of heat does not demand in addition enclosed energy. Solar collectors are several types.
Types of solar collectors
By the principle of the device the collectors subdivide into vacuum and flat. In vacuum collectors the heat exchanger is served by a tube with double walls in an interval between which there is a vacuum. The internal tube consists of material with very low reflecting ability. The branched system of tubes is hidden under several layers of armored glass at what it in the collector's cavities also can air for decrease in a thermolysis is pumped out. Thus, the most part of energy is absorbed by a tube with the heat carrier, at the same time there are no losses of heat to the environment. Heat exchangers of this kind differ in high efficiency, but cannot independently be cleaned from snow.
Flat collectors have much simpler design, and therefore cost them many times below. The layer of light-absorbing material is applied on the smooth or covered with a special relief plate with good heat conductivity. It heats up under the influence of sunlight and transfers heat to the system of the copper or polyethylene tubes located on the panel back. between tubes and the panel the reliable thermal contact is provided, also tubes can be profile type for the bigger area of contact with the panel.
Prospect of development of the industry
The main problem of systems of solar heating - their high cost. With development of production and improvement of polymeric materials such lack of systems of solar heating can be solved, however their improvement is not favorable to the business based on extraction of hydrocarbons and their sale to the population of the planet. Today positive dynamics of development is observed: since the beginning of the 21st century the application of solar collectors increased from three to ten times in different countries of the world.