Hesse's geothermal energy offensive: opportunities and risks of geothermal energy discovered!

Hesse's geothermal energy offensive: opportunities and risks of geothermal energy discovered!

The Hessian State Energy Ministry has announced that the expansion of geothermal energy in the region will be significantly advanced. This measure is part of a comprehensive strategy to actively combat climate change. Geothermal energy offers significant advantages for the energy transition, but also poses certain risks. The energy from the earth is theoretically available everywhere, regardless of weather and season, and also requires less space than conventional renewable energies such as solar parks, wind power and hydroelectric power plants. The Upper Rhine Graben, which extends to Frankfurt, is considered particularly suitable for deep geothermal energy.

Nevertheless, the ministry points out the risk of discovery. This is the risk that geothermal drilling will develop a reservoir of insufficient quantity or quality, which may limit the economic use of geothermal energy. These risks have become particularly clear through botched drilling, as was observed in Staufen in Baden-Württemberg. To counteract these concerns, the federal government is planning discovery insurance and improving the data situation on geothermal energy.

Potentials and challenges of geothermal energy

Improving data and monitoring systems is crucial for the further expansion of geothermal energy in Hesse. An overestimation of the discovery risk is necessary because this measure could increase confidence in geothermal use. Experts distinguish between near-surface (up to 400 m), medium-deep (400-1,000 m) and deep geothermal energy (over 1,000 m). A recent test drilling in Frankfurt reached a depth of 1,060 meters and showed high subsurface temperatures, further fueling hopes for profitable use of geothermal resources.

By the end of 2023, around 9,900 geothermal probe systems were in operation in Hesse. The use of drilling to augment data between 2019 and 2024 is expected to help reduce uncertainties. However, geothermal energy-powered heating networks remain rare in the region, which is due to high costs and the risk of discovery. Near-surface use with geothermal probes and heat pumps can be useful in areas without deeper geothermal energy.

Environmental influences and water temperatures

However, the BUND has also warned of the possible negative consequences of warming groundwater through the use of heat pumps. Although geothermal probes require a permit, there is a lack of continuous monitoring of groundwater temperatures. The quality of the water developed during drilling is another important aspect, as undesirable chemical components can make geothermal use difficult or even impossible. In Germany, all water encountered was previously manageable for geothermal applications, but the technical effort involved varied.

In summary, it can be said that geothermal energy can offer great potential for the energy transition in Hesse, but also brings with it challenges. The planned measures to minimize risks and improve the data situation are crucial for the successful and sustainable use of geothermal resources.