Heat from the earth

Geothermal energy is stored in the form of heat below the solid earth surface. The amount of heat available in the earth (earth’s heat) would cover the current worldwide energy requirements for 30 million years. According to human measure, the energy supplies stored in the earth are just as inexhaustable as those of the sun.

In Central Europe the temperature in the top layers of the earth increases by an average of 3 °C per 100 metres of depth. In the top mantle the temperature is approx. 1 200 °C, in the earth’s core it is estimated that this temperature increases to 6 000 °C. Just below the surface of the earth temperatures are almost only determined by the sun and rainfall. Since the soil is a poor heat conductor, the influence of the sun can no longer be established at a depth of only 15 to 20 metres.

In comparison to other renewable energy carriers, the earth’s heat has one significant advantage: it is always available, irrespective of the times of day or year or the existing weather conditions. Since it is available on site, no costly transport systems are required.

Since no conventional combustion processes take place, no CO2 emissions are created, except perhaps through the operation of a heat pump. Today technology is available that allows the existing heat resources of the earth to be utilised virtually everywhere.

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