Wien Energie to build first geothermal heating plant in Vienna, Austria

Wien Energie to build first geothermal heating plant in Vienna, Austria Announcement of Aspern geothermal heating project in Vienna, Austria (source: Wien Energie LinkedIn page)
Carlo Cariaga 15 Nov 2022

Vienna, Austria city utility Wien Energie will be developing the city's first geothermal heating system in Aspern with a planned 20 MW capacity.

The green light has been given to proceed with the first geothermal heating project in Vienna, Austria. This project will be undertaken by Vienna’s city utility, Wien Energie, and will see the construction of a geothermal heating plant on the outskirts of Seestadt Aspern.

The planned geothermal heating plant will have an output of 20 MW – enough to supply the heating needs of 20,000 households. If all steps go according to plan, pre-drilling work for the project will begin by 2023 with a target commissioning by 2026. One-tenth of the EUR 80-million investment that will go toward the project will be contributed by the federal government.

Earlier this year, Wien Energie had announced a EUR 1 billion investment to phase out gas use in Vienna. This investment will expand the use of photovoltaics, wind power, heat pumps, and geothermal heating.

Resource found through the GeoTief project

Between 2016 and 2022, Wien Energie carried out a comprehensive investigation of the geological conditions under Vienna along with partners from science, research, and industry. The GeoTief project involved the Federal Geological Agency of Austria, Geo5, OMV, the University of Vienna, and the University of Salzburg among others.

A key result of the GeoTief project is the identification and modeling of the Aderklaa conglomerate, a water-bearing rock layer below the city. It is this formation that will be targeted by drilling for geothermal exploitation.

3D model of Vienna subsurface highlighting the Aderklaa conglomerate (source: GeoTief Wien)

An exploratory borehole will first be drilled to assess the quality and flowrate of the thermal water. If results are encouraging, two additional boreholes will be drilled to around 3000 to 3500 meters depth. These boreholes will constitute a doublet from which heat will be extracted using a surface heat exchanger.

Additional geothermal heating plants

The geothermal heating plant in Aspern is planned only as a pilot project. The thermal water potential under Vienna is said to be enough to supply heat for up to 125,000 households.

If the project is successful, there are plans to have up to four deep geothermal systems in Donaustadt and Simmering. This will be enough to supply up to a fifth of the district heating demand of Vienna. Expansion plans are to be continue beyond 2030 with a target for the city to generate heat entirely from climate-neutral sources by 2040.