The sun is a source of life for the whole world. Supplying more then 1, 7.10 MW a year, witch is equally 5 million tons of coal and is 10000 times more than the whole energy consumed by humanity over a year. A long time the energy of the exhausting sources produce energy, witch is harming the atmosphere and the air, the flora and fauna and more important it isn’t endless, which is something that humanity should think about carefully. With the development of these new technologies, witch use solar energy and the new experience we gain, we understand that this way of heating can be used in a way to fulfill our energy needs. The use of solar energy is not only important for conserving other energy sources, but is leading to some economic profits.
According to some modern conceptions the out layer of the sun is forming the sun crown with a temperature around 1 000 000 C. But the emanating surface is with temperature 6000 C. The emanating ability of this surface is about 80 000 kWh/m2. The solar energy that is delivered towards Earth (for a Year) is around 1 000 000 000 000 000 MW/h and is 20 000 times more than the whole use of energy all over the world. On the Out sphere of the atmosphere of Earth the intense of solar radiant is around 1360 W/m2. It depends from the number of sun spots on the surface of the Sun. There have been measured supreme values of over 2100W/m2.
In optimum conditions the values can rise up to 950-1100 W/m2.


The year amount of solar radiation entering 1 m2 for the area of Bulgaria. In a constant increasing rate for all the exhausting energy sources, the use of reviving energy sources is becoming a more reliable way. One of the advantages of the use of those sources is the free consume. Namely this rise of the electricity, gas, oil, coal and so, are helping the faster payment of the systems made by solar collectors.