Geothermal Energy – Heat of the Earth
During the construction of a geothermal heating, you drill a 50 to 400 m deep hole. You have to go that deep because down there there are no seasonal weather and temperature changes. The diameter of the hole can be up to 160 mm. In general, there are two pressure-resistant plastic pipes. A heating fluid circulates through the two tubes, the fluid is heated in the bottom of the tubes and the heat is transfered to the house.
In a typical, privately used single-family house, 3/4 of the heating demand should be provided by geothermal energy to guarantee a profitable use.
Our house and also many houses in the neighborhood, especially the new ones, are heated with geothermal energy.
Video 1: adding a drill rod (Bohrstange ansetzen)
Video 2: Geothermal drilling machine
Geothermal drilling in Seegräben, Kanton Zürich
Test drilling in Uster City
For examining the underground there’s a test drilling needed – in the following example a bore hole of about 80 m. The data collected will result in a geological expert study. Based on the geological profile the exact drilling depth for the geothermal heating system can be determined.
Video & photo source: Teacher T&U, Elaine Suter