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German Geothermal Potential

When it comes to geothermal energy, Germany is feeling the heat – literally and figuratively – beneath its feet.

According to the head of the German Geothermal Association, “Geothermal sources could supply Germany’s electricity needs 600 times over.”

Werner Bussmann, the organization’s CEO, added, “Geothermal electricity has the advantage of being available 24 hours a day, 8,000 hours a year, and this makes it a great source of baseload power.”

This is exciting news, for in 2004, only 0.4 percent Germany’s total primary energy supply came from geothermal sources.

Two factors have largely attributed to the boom in geothermal, both in actual power plants being constructed and in overall interest in the country’s energy sector:

  • A new law was introduced that allowed for the drilling of wells deep enough to hit the hot temperature water that’s needed to produce electricity in a financially viable way.
  • A renewable energy law that introduced a tariff scheme of EU 0.15 [US $0.23] per kilowatt-hour (kWh) for electricity produced from geothermal sources was instituted.
  • Bernd Hildebrandt, marketing director, DMT GmbH & Co. KG Exploration & Geosurvey Division Geothermal Energy, Germany, agrees that the country’s potential is significant.
  • “There are some areas in Germany applicable for geothermal, like the northern plain, the upper Rhine rift and the Molasse at the foothills of the Alps (where Munich is located),” he said. “Since the German government finalized the laws for renewable energies and the economic stimulation, there is a real boom in geothermal activities.”
  • Projections for the entire country indicate that within five years there could be more than a hundred plants operational in the country. This year alone, plants in Sauerlach, Dürrnhaar, Riedstadt, Speyer, Gross Schoenebeck and Mauerstetten are slated for operation. All told, these plants represent an investment of approximately four billion euros by the German government.
  • Two projects – one already online, one planned – are particularly exciting. And both are in Unterhaching, a suburban town with a population of 23,000, outside of Munich.
  • The first, sponsored by DMT GmbH&Co. under a contract with the Liebnitz Institute for Applied Geophysics, features exploration in the Upper Jurassic strata in the Molasse Basin between the Daube and the Alps.
  • Some believe this may be central Europe’s largest geothermal energy reservoir suitable for providing heat and for generating electrical power.
  • “Having assembled a team of 50 to 60 people, we are exploring an area covering about 20 square kilometers,” said Rudiger Misiek, the Essen project manager.
  • “To achieve the scientific quality, we will be measuring along a dense matrix at gridline intervals of just 300 meters.”
  • Misiek said the purpose is to help “optimize the use of potential geothermal sources.”
  • The second is an actual working geothermal plant – Germany’s first major investment in exploiting heat from the centre of the earth.
  • This 3.5-MW plant, which supplies 20,000 households with electricity and heat, is also the first geothermal plant in Germany to use the “Kalina” technology that allows energy to be extracted from water of low to moderate temperatures. Specifically, at this plant, water is extracted at a temperature of 122 degrees Celsius from a well 3,500 meters deep at a rate of 150 liters a second.

As mentioned, geothermal power had up to this point been only an insignificant part of Germany’s electricity mix.

There are special challenges to geothermal in Germany that require unique technology, because unlike Iceland, Italy or Indonesia, Germany does not have volcanic activity or the dry steam reservoirs needed to produce electricity directly.

And in urban areas like Munich, there are special challenges.

“The specific difference,” Hildebrandt said of the challenges in exploring for geothermal in urban areas, “is the special protection of narrow building density. You have to reduce the vibrator peak force. You have to pick the vibrator points with special care to infrastructure like service pipes.

“A special attention will be needed for safety clearance distance,” he continued. “To ensure that buildings will not be damaged by seismics you have to measure and monitor the emission of vibration within the buildings. The layout of the measuring cables need more attention because of high-density traffic. And, at least, there are different problems to solve in traffic routing and safety.”

Specifically, roads and working platforms have to be constructed so that exploratory and production equipment can be brought in, which can adversely affect local plants and wildlife.

Once the drilling begins, further damage can ensue, as the deep well passes through some underground water bodies, which can be contaminated by drilling fluid. Increased temperature of the area can kill life forms in the water. Moreover, mud disposal is another consideration, as are the gases in the geothermal fluid – including carbon dioxide, hydrogen sulfide, methane, sodium chloride (salt), boron, arsenic and mercury – and hot water can leak into surrounding areas and threaten the ecosystem.


Another hurdle, as it is in every form of exploration, is money and technology.

Before the geothermal plants can be built – and the lifespan of them is about 30 years – there has to be enough of the proper drilling equipment available to reach the aforementioned hotter water needed for electricity generation. And right now there isn’t enough equipment available.

As such, this deficiency is increasing the price of geothermal power plants. Equipment to build the plan counts for approximately 60 percent of its cost, or between 30 and 40 million euros (approximately $50-60 million). Bussman says these costs have doubled in the last three to four years.

Another area of great concern – maybe the major concern – is whether the boreholes themselves, which can cost up to $5 million, will bring sufficient hot water to the surface to make the specific geothermal project a financial and energy success.

Unfortunately, until a borehole has been completed it’s impossible to tell how much geothermal water can be extracted. That’s a big if for investors.

What some in Germany have suggested is for the government to set up a fund that would help insure investors from these bore holes not coming to fruition. Such a fund, proponents advocate, would be privatized as soon as the number of projects has increased and there is more data at hand.

Still, to many, geothermal is not only the brightest star out there, it is the only one out there.

Doug Heffernan, CEO of Mighty River Power Ltd., from New Zealand’s No. 3 power retailer, said, “Geothermal is going into a renaissance age. It’s the only reliable renewable.”

Germany apparently agrees.

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Emphasis: International