A geothermal power plant with special drilling technology is being built south of Munich. Energy is to be generated from a depth of 4,500 meters. Experts see new opportunities for power generation.
Preparations for the drilling site have been underway in Geretried, Upper Bavaria, since October 2022. In July, the Canadian company Eavor Technologies then committed the so-called chisel consecration to start drilling. But it actually started much earlier: the first boreholes in search of hot water had already penetrated to the record depth of 6,000 meters ten years ago. In 2013 it was the deepest borehole in Europe. Water was not found then – but hot rock.
Hot stones heat water
The company now wants to use these layers of rock in the so-called Upper Bavarian Molasse Basin as a deep heat exchanger for environmentally friendly energy production, explains Daniel Mölk, the project manager for the geothermal power plant. The technology is new and has so far only been tested in a small test facility near Calgary in the Rocky Mountains.
A large number of horizontal tubes, the so-called loops, are drilled into the rock at a depth of around 4,500 meters. Then water is channeled into the depths. This water heats up in the rock, which is up to 170 degrees hot, and returns to the surface at a temperature of up to 120 degrees Celsius. This technology is made possible by the fact that the underground has been geologically well researched. The operators hope that no water will escape underground at the intersections of the tubes.
promising Technology
The plant is to be operated as a base load capable power plant for generating electricity. In a further step, the town of Geretsried with its 25,000 inhabitants is to be connected to district heating. In the final stage, the plant will supply 8.2 megawatts of electricity and 64 megawatts of thermal energy. The loops in the rock form a closed tube system with a total length of 80 kilometers. The first of a total of four planned tubes is scheduled for completion in autumn 2024.
If the new technology works, according to geoscientists, heat generation with the “Eavor Loop” would be possible in many parts of Germany. Inga Moeck is one of the leading scientists for geohydraulics and geothermics in Germany and teaches at the University of Göttingen. With the new technology, “if it works”, deep heat can be obtained almost anywhere in Germany, she says. Exceptions were the Upper Rhine Graben or other earthquake-prone areas. The key to this form of energy generation lies in the new drilling techniques that the Canadian company has developed.
Scholz and Söder visit the construction site
Eavor Technologies was founded in Canada in 2017 by specialists from the energy industry. Numerous patents in drilling technology are the basis for the closed system of the “Eavor Loop”. During a visit to the construction site, Chancellor Olaf Scholz (SPD), Federal Research Minister Bettina Stark-Watzinger (FDP), Bavaria’s Prime Minister Markus Söder (CSU) and Bavarian Economics Minister Hubert Aiwanger (free voters) also want to meet Canadian politicians and technicians today.
Some experts believe this technology could fill gaps in the supply of clean, zero-emission energy. The construction costs of the plant are estimated at 250 to 300 million euros. The European Commission is supporting the project with around 92 million euros from an innovation fund.