Solar heat

With solar thermal use of the sun's energy the radiation of the sun is converted into thermal energy by means of collectors. In Germany, solar heat is usually used to heat water for showers and washing or for space heating. In addition, solar thermal systems are frequently used to heat swimming pool water.

Solar collectors absorb solar radiation, convert it into heat and pass the heat to a heat transfer medium. This is pumped through a pipe system to a storage device; there the heat is transferred to the domestic hot water with the help of a heat exchanger and, now cooled, the heat transfer medium flows back to the collectors. The controller keeps the pump in operation as long as usable heat is available in the collectors. In the winter a boiler based on natural gaz provides the missing heat.

A collector area of 4 to 5 square metres is sufficient to provide around 60 percent of the hot water in a detached house. Solar collectors with an area of 8 to 15 square metres can even supply around one quarter of the total requirements for heating and hot water.