How does geothermal energy work?

How does geothermal energy work?

Students from Butzbach asked questions at a drilling site:

How does heat from the ground get into a building? What must be considered when drilling into the ground? These and further questions were asked by a class of engineers-to-be at the Butzbach Vocational School and Technical College when visiting a building site in Wetzlar.

The students and their teacher visited a particularly large geothermal project in Wetzlar’s industrial estate Spilburg. Here the Leitz-Park GmbH is building a new production and administration building for the Leica Camera AG. This will not be heated by burning natural gas or oil, but in an environmentally-friendly and climate-friendly way utilizing geothermal energy. Professionals are needed for a task like this: Fulda’s geothermal company TERRA THERM Geothermal GmbH drilled over 70 boreholes to a depth of approximately 120 meters at the construction site. TERRA THERM employee Matthias Schneider told the students: "This project was a special challenge for us. We have already drilled a total of many thousand meters in the private and commercial sector, but the planned building complex is interesting because of its size and the amount of probes needed. We install 79 probes, each at a depth of 120 meters. This results in a total length of 9480 meters of drilling."

Cost-effective and low in CO2 emissions.

This view was shared by the students. They watched the professionals operate one of the company’s big drills. High performance drill heads penetrated into regions of the ground where the temperature stays constant at a certain level in both summer and winter. The heat in the ground is brought to the surface by geothermal probes and raised to an even higher temperature level by a heat pump. Schneider explained to the students:  “In terms of proportions, four parts of heating energy can be obtained from one part of electricity used for running the heat pump and three parts of free geothermal energy from the ground. As the same installation can be utilized for air conditioning of the premises in summer and the primary energy is not provided by fossil fuels, it is also particularly cost-effective.” Teacher Kai Koethe said: "Our students have been introduced to the theory of using geothermal energy at school, but have not had the possibility to experience the drilling process live so far. The size of the construction site on which several drill heads are driven into the ground at the same time shows the important role that geothermal energy plays within the sector of renewable energies nowadays. It is great to be able to ask questions directly to experienced professionals. "