Natural gas is becoming more and more expensive, and the owners of oil heating systems are also moaning about the high prices.

As a result, renewable energies are increasingly coming into focus.

For example, geothermal energy, also known as geothermal energy, can in many cases help to heat the home.

According to current knowledge, the temperature in the earth's core is estimated at more than 5000 degrees.

The heat there is practically inexhaustible.

But you don't have to penetrate to the core of the earth: the ground temperature in Germany rises by about three degrees for every 100 meters of depth.

The Hessian State Agency for Nature Conservation, Environment and Geology (HLNUG) and the State Energy Agency of Hesse (LEA) want to find out the geothermal potential in Dietzenbach with an exploratory drilling.

The drilling rig was set up on the site of the old city garden center on Grenzstraße.

The drill bit at the tip of the drill pipe is to work its way down to a depth of 100 meters.

rock samples taken

20 locations in Hesse, including Frankfurt, Offenbach, Hofheim-Wallau, Heidenrod, Riedstadt-Goddelau and Büdingen-Düdelsheim, were selected for such drilling.

Dietzenbach is the only town in the district of Offenbach.

The Mayor of Dietzenbach, Dieter Lang (SPD), spoke of "another building block for more climate protection through regenerative energies and away from the fossil exploitation society".

The project was started by the state office in 2019, and the state energy agency has been involved since 2020.

During drilling, rock samples are constantly being taken, which the State Office is geologically examining.

The experts lower a geothermal probe into the ground opening and then backfill the borehole with a mixture of cement and bentonite.

It should firmly connect the probe to the surrounding rock, which causes a high heat exchange.

Two weeks later, a specialist company carries out a so-called thermal response test, in which the thermal probe is connected to a test facility.

In this way, the thermal conductivity and temperature of the substrate are determined.

The state office wants to determine the geothermal potential of the region from the data.

The results are published in a profile on the State Office's website.

Based on this information, geothermal systems for private, municipal and commercial buildings could be planned more reliably, emphasized Dietzenbach's First City Councilor and Head of Building, René Bacher (Die Grünen).

If a building is to be supplied with energy from geothermal energy, a similar drilling is required.

A geothermal probe is usually installed at a depth of up to 100 meters.

The temperature there is around twelve degrees.

A carrier liquid circulates in the geothermal probe, which heats up underground and thus brings the heat upwards.

Heat pumps in the building further increase the temperature so that heating and water can be heated.

According to those involved in the exploratory drilling, up to six kilowatt hours of heat are generated for every kilowatt hour of electricity that the heat pump requires.

This can also be used for cooling in summer.