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City of Vienna sees start of large-scale geothermal research project

Votive church tower, Vienna, Austria (source: flickr/ Herr P., creative commons)
Alexander Richter 1 Oct 2018

The city of Vienna in Austria is now seeing the start of a large scale research project that is to explore the resource potential for potential large scale geothermal heating development.

As reported today from Austria’s capital of Vienna, the GeoTiefWien geothermal research project is now entering its decisive phase. The 3D seismic measurements in the 2nd, 11th and 22nd district of Vienna start at the beginning of October. 50 terabytes of data are to be collected on the Vienna Underground.

The first investigations in February and March 2017 are now followed by detailed 3D seismic investigations. The potential of the hot water occurrence in the Vienna subsoil will be investigated in more detail after 26 kilometers of 2D seismic measurements have been investigated. The knowledge gained from 2D seismic surveys forms the basis for the planning, execution and evaluation of the 3D seismic that is now beginning.

If the results of the 3D seismic show that sufficient geothermal potential exists, the energy source should ideally cover the heat supply for hundreds of thousands of Viennese households.

From the beginning of October, so-called impulse vehicles are traveling for six to eight weeks in the east of Vienna and a small part of the neighboring Lower Austria. The impulse vehicles will send vibrations – similar to sound waves – up to 6,000 meters deep into the ground. These vibrations are reflected and recorded by sensors. In total, an area of 175 square kilometers is covered.

The whole area is marked before the measurements are started and sensors, so-called geophones or earth microphones are laid out. Migratory convoys, each consisting of three impulse vehicles, will travel the entire route and carry out measurements every 20 meters. The public will be informed throughout the duration of the measurement.

50 terabytes of data are collected in total. The data is then merged with known data and evaluated by experts. From this, a three-dimensional image of the subsurface is created, which should provide information about the location and size of potentially water-bearing rock layers. Due to the high complexity of the geophysical and geological analyzes, the evaluation will take two years and should be completed in 2021.

Michael Strebl, chairman of the Wien Energie management explains that currently 40 percent of Vienna’s energy consumption is attributable to the heating sector. To save further CO2 emissions must be set here. Geothermal energy offers enormous potential to achieve this goal. The extent to which it can be used in Vienna will be determined by means of 3D seismic measurements.

According to various studies, the potential of deep geothermal energy in Austria is between 450 and 700 megawatts. Up to 60 percent of it should lie in the underground of Vienna. Since there are also the appropriate number of customers, a promotion of hot water resources from great depths is feasible.

Source: Wien Energie Gmbh via TiefeGeothermie.de