German Chancellor Olaf Scholz together with the state premier of Bavaria, Markus Söder, during a visit to the construction site of the pioneering Eavor Loop 'closed-loop' geothermal plant in Geretsried near Munich, has pledged to give a boost to the technology.
The plant that is scheduled to partially start operations next year will generate about 64MW of thermal power for heating and 8.2MW of electrical power, from four of the closed loops by Canadian start-up Eavor, saving approximately 44,000 metric tons of CO2 equivalents per year.
Eavor, which has secured backing from the likes of BP, Chevron, and Japan’s Chubu Electric, in 2020 presented its technology based on a closed loop in which cold water — or a similarly behaving working fluid — travels down a 3-5km pipe, then underground horizontally through hot rocks for a few kilometres, up another pipe and along the surface back to the start. The heated-up liquid at the surface can be used for district heating and power generation.
"To use this heat also above ground is so obvious as this heat is always there, independent of wind and weather, independent of the seasons," Scholz said.
The Chancellor stressed that Bavaria is the focal point of geothermal drilling in Germany, with much of Germany’s 42 deep geothermal plants located in the state. Another 12 are being built, and 82 more are in planning.
But much more is possible, he added, pointing to studies that geothermal could cover a substantial part of Germany’s heating needs.
"Our goal is to tap as much geothermal energy as possible by 2030 and to feed ten times as much geothermal energy into the heating network as today," Scholz said.
"This is ambitious, but a secure and, above all, affordable supply of renewable energy is an advantage that is crucial not only for our citizens but also for our economy. For location decisions and for investments.
"I wish ... that Germany will be the first country in Europe where the Eavor Loop works on a significant scale."
The country so far generates 417MW of heat and 46MW of electricity from deep geothermal plants (heat pump installations not included).
In the construction of the Eavor-Loop in Geretsried, Eavor is working with two drilling rigs operated in parallel. These initially drill vertically to a depth of around 4,500 meters. There, the wells are directed horizontally. Several parallel branches are created, each 3,200 meters long. The challenge is to connect the boreholes at depth so that the underground heat exchanger is created, the company said.
The Bavarian project is the world’s first commercial implementation of an Eavor-Loop. The company already has a pilot plant operating with the technology in Alberta, Canada.
The EU Commission earlier this year said construction of the project in Bavaria will be supported by a grant of €91.6m ($99.3m) from the European Innovation Fund EIF – or about a third of the expected total cost of the plant.
Eavor says that no thermal water is required for its technology, which thus has advantages over the hydrothermal geothermal energy that has been widely used to date.
Borehole drilling as deep as 6km at Geretsried ten years ago hadn’t produced any hot water – so traditional geothermal technologies couldn’t be used – but hot rocks were discovered at the time, which now are slated to be tapped in by Eavor.
“Our primary interest is focused on district heating, because the energy that can be generated here with the Eavor-Loops could satisfy a considerable part of the heating needs in the urban area, and that’s a great opportunity in terms of climate protection and energy security,” said Jan Dühring, CEO of the Stadtwerke Geretsried, a municipal utility in the Munich suburb.
All four loops at the plant are slated to be built by 2027.