The Bavarian town of Geretsried will test a novel way of extracting energy from the earth, the AP news agency reports.
The plan is to borrow oil and gas drilling techniques to extract heat from dry, hot rock up to 4km below the surface.
The experiment is being carried out by Canadian geothermal specialist Eavor, which hopes to open a commercial power station to supply the town’s 26,000 population.
The project follows the failure of an attempt to locate hot water close to the surface, carried out in 2010.
It hopes to start generating electricity in Geretsried this year, later supplying a district heating system.
If it succeeds, the system could be reproduced almost anywhere.
40% of heating needs
According to a geothermal masterplan for the state of Bavaria drawn up by the Technical University of Munich, deep geothermal energy alone could cover as much as 40% of the state’s heating needs.
John Redfern, Eavor’s chief executive, told AP that Geretsried was chosen because the people were enthusiastic about the idea of clean energy, and it had “ordinary geology”, so that if it worked there, it would also work in many other places.
“Our whole point is that we want to have geothermal anywhere, everywhere,” Redfern said. “What better way to prove that than to put our first well where they tried and failed with traditional geothermal systems?”
Closed-loop system
Eavor’s method involves circulating a proprietary fluid through two primary vertical wells – an inlet well taking cooled fluid down, and an outlet well sending heated fluid up.
The fluid is contained in pipes and doesn’t come into contact with the water table.
The system converts the heat carried up into electricity with a heat engine.
The loop is connected to a dozen lateral wells at depth, drilled horizontally to maximise contact with the hot rock.
The Geretsried project will have four loops, each with two vertical wells and about 12 lateral ones.
Eavor is licensing its technology to utilities and companies that are trying to reduce their carbon. A large Japanese power provider, Chubu Electric Power Company, is an investor.
Japan has many sites suitable for geothermal exploitation, but few have been developed.
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