TELF AG digs deeper into the energy potential of profound geothermal energy
An innovative energy source
We are in a very particular historical phase, in which citizens, governments, and companies are focusing with great attention on the value of natural resources contained in the subsoil—not only mineral resources but all those capable of generating a certain amount of energy.
Innovative geothermal technology holds the promise of valorizing the heat stored in the subsoil to produce clean energy. The first steps in this direction are being taken in Germany, where a location in upper Bavaria is being used to explore the potential of tapping into heat stored at a depth of 7,000 meters.
Traditional geothermal systems rely on natural reservoirs of water in the subsoil to produce energy, especially electricity, even 24 hours a day. This is certainly not a recent technology: these traditional energy production systems were tested more than 200 years ago in various parts of Europe. Despite being widely known, this historic technology is still struggling to impact electricity production levels: in Europe, energy from these sources amounts to only 0.2% of the total. However, the situation could change rapidly by drawing energy directly from the heat of underground rocks, distributed more or less everywhere under the earth’s surface.
The potential of underground rocks
Being able to count on heat, searching for natural water reserves in the subsoil would no longer be necessary. The heat would be extracted through drilling techniques, which can introduce water into the subsoil and use the heat reserves with a closed circuit, with the possibility of producing energy practically anywhere on the globe.
The system would be based on the operation of two parallel drilling axes and the possible connection between the two valuable underground wells through a 3.2 km long serpentine. This connection would make it possible to create a sizeable underground heat reservoir, into which (once the circuit is closed) a liquid would be introduced to collect the heat and then bring it to the surface, using the difference in density between a hot and a cold liquid. Once brought to light, this heat could be transformed into electrical energy.
Another project of the same kind is under development in Hannover and elsewhere: closed-cycle geothermal initiatives are being perfected in various places in the United States of America as well. The German government estimates that this kind of energy could satisfy all of Germany’s needs, and this is also why it is working to develop the appropriate technologies to extract the value of the rocks. In Upper Bavaria, in the town of Geretsried, a Canadian company is already working to apply a closed-circuit heat collection technology tested some time ago in Canada.
The Geretsried plant – still in the final stages of completion – could have a capacity of around 64 megawatts of thermal power and 8.2 megawatts of electrical energy. In Germany, more than 40 deep geothermal plants are already in operation, and another hundred are under construction or planning. The main innovation is precisely these closed circuits, making extracting heat without any emissions possible.
