A subsidiary of the TÜV NORD GROUP, DMT, has begun a 3D seismic survey on behalf of Stadtwerke München to investigate the deep subsurface, with the collected data aiming to provide a three-dimensional image of the area to form the geological basis for further development of deep geothermal energy in Munich.
The thermal reservoir in the Greater Munich area is already being utilised via 50 boreholes with a total thermal output of 400MW. The additional available potential is estimated at more than 1,000MW, which is being precisely determined through the largest-ever seismic survey in a highly populated area, sitting at around 1,100 km2.
The new data can be used to identify potentially suitable sites for future geothermal projects, to develop existing plants, and to coordinate the use of geothermal energy in the study area in the long term.
Funded by the Federal Ministry for Economic Affairs and Energy (BMWE), the GIGA-M project is a joint initiative involving the Technical University of Munich (co-ordinator), Stadtwerke München (head of the seismology team), Energie-Wende-Garching (seismology partner), the Ebersberg-Munich Energy Agency, the District of Munich and the City of Munich.
Dr Maik Tiedemann, CEO of DMT and the TÜV NORD GROUP’s Energy & Resources, said, “With GIGA-M, we are setting a new benchmark for seismic site exploration in urban areas. Large-scale 3D seismic surveys provide the data required to assess and systematically develop geothermal potential in the Greater Munich area. The experience gained can also provide important impetus for other cities and regions that want to develop deep geothermal energy as a component of their heat supply.”
Vibro Trucks will be used for the measurements. The truck transmit controlled vibrations into the ground and are reflected off the various rock layers and analysed. The image data is used to create a high-resolution 3D model of the subsurface, which provides information on geological structures and areas potentially suitable for deep geothermal energy.
Dr Christian Henke, Head of Seismic Exploration & Processing at DMT, commented, “A 3D seismic survey of this scale poses unique challenges in terms of planning and execution. In the densely populated survey area, a large number of measurement points, the deployment of vibro-trucks and the recording by thousands of geophones must be precisely co-ordinated. It is essential to generate a consistent data set across the entire survey area, from which the 3D model of the subsurface is subsequently created.”