OMV and Wien Energie are drilling three kilometers deep in the joint venture deep

Sustainable energy from the depths for Vienna's district heating: That is the goal of deeep, a joint venture between OMV and Wien Energie. Starting today, drilling will be carried out in Aspern (Vienna-Donaustadt) to a depth of more than 3,000 meters. The city's first deep geothermal plant is an important milestone on the way to a climate-neutral heat supply for Vienna. Once completed, the plant in Vienna's 22nd district will feed into the district heating network and then cover the needs of 20,000 Viennese households without producing any emissions.

"The development of deep geothermal energy is a future project - like the high spring water pipeline or the Danube regulation - that will continue to contribute to the quality of life in our city for well over a hundred years," explains Peter Hanke, City Councilor for Economic Affairs, Finance and Vienna Public Utilities. "This deep geothermal plant is a far-sighted project that is exemplary for our city. We are not only generating energy here, but are also strengthening our independence from energy supplies and thus the business location."

The Aspern deep geothermal plant is scheduled to go into operation in 2028, with further plants to follow. OMV and Wien Energie estimate the technology's potential for the city to be equivalent to the heat requirements of around 200,000 Viennese households. Deep geothermal energy can thus play an important role in the city's climate-neutral heat supply, which is to be achieved by 2040. The first deep geothermal plant will serve as the basis for further expansion.

"Geothermal energy is an important element of our Strategy 2030, with which OMV is driving the transformation into an integrated sustainable company for chemicals, fuels and energy. We have unique knowledge of the geology of the Vienna Basin. We are using this know-how, combined with many years of experience in exploration and production, together with Wien Energie in our innovative district heating project for Vienna. With deeep, we are reducing CO2 emissions and offering an energy solution for a sustainable future. At the same time, geothermal energy increases security of supply and supports the diversification of energy sources," says Berislav Gaso, OMV Board Member and Executive Vice President Energy.

Peter Weinelt, General Director of Wiener Stadtwerke, adds: "With this first deep geothermal plant, we are taking a big step closer to our goal of operating district heating in a climate-neutral manner by 2040. In just a few years, we want to generate climate-neutral heat here for the equivalent of 20,000 Viennese households. With today's start of drilling, Wien Energie and OMV are setting the starting signal for the use of deep geothermal energy in Vienna."

Natural hot water deposits under Vienna

Deep geothermal energy is the use of geothermal energy at a depth of more than 300 meters. In Vienna's case, a natural hot water source around 3,000 meters underground, the so-called "Aderklaaer Conglomerate", is tapped. This formation water is located in an aquiferous rock layer and is around 100 degrees Celsius at this depth.

"Vienna is particularly lucky because it sits on a large heat treasure - and after years of research and planning work, we are now going to exploit it," explain the managing directors of Wien Energie, Michael Strebl and Karl Gruber. "With the first deep geothermal plant for Vienna, we are generating even more climate-neutral district heating. In this way, we are contributing to security of supply and also to price stability, as we are becoming a further step less dependent on gas imports."

Renewable Cycle

When the plant is in operation, the hot formation water is pumped up to the surface. The heat is extracted from the water via a heat exchanger and fed into the district heating network. The cooled water is then returned to the original reservoir, creating a closed circuit. One of the advantages of the technology is that this energy source is available evenly and all year round.

A total of three boreholes are required for the deep geothermal pilot plant in Aspern: a pilot borehole for exploration, maintenance and safety, a production borehole and an injection borehole through which the water is returned.

The drilling is scheduled to be completed in mid-2025. This will be followed by production tests to check the availability, temperature and chemical composition of the formation water. The above-ground plant can then be built. The Aspern deep geothermal plant is scheduled to go into operation in 2028.

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