Preparations are being made to start drilling for the first deep geothermal plant in Vienna
An important milestone has been reached for Vienna's first deep geothermal plant: OMV and Wien Energie, through their joint venture deeep, have completed the necessary approval procedures and are beginning to set up the well site.
Peter Weinelt, CEO of Wiener Stadtwerke, stated, “Vienna offers ideal conditions for the use of deep geothermal energy. We have a large natural hot water reservoir deep under the city and a well-developed district heating network to distribute the energy to customers. This not only benefits the climate but also enhances supply security and price stability, making Vienna less dependent on gas imports.”
Currently, deeep is preparing the well site in Aspern (Vienna-Donaustadt) for drilling, which is set to commence in winter 2024/2025. The plant aims to provide climate-neutral district heating for the equivalent of up to 20,000 households in Vienna. Michael Strebl, CEO of Wien Energie, explained, “After years of research and planning, we are now beginning implementation. Alongside OMV, we established the joint venture deeep last year to combine our strengths. Our goal is to utilize deep geothermal energy to advance the heating revolution in Vienna and achieve carbon-neutral district heating by 2040. The construction of Vienna's first deep geothermal plant brings us closer to this objective.”
The deep wells are central to the facility in Aspern, reaching depths of over 3,000 meters to utilize hot formation water for heat generation. OMV is responsible for the subsurface aspects of the deeep project. Alfred Stern, Chairman of the Executive Board of OMV Aktiengesellschaft, noted, “OMV is committed to achieving net-zero emissions by 2050 at the latest. Geothermal energy plays a vital role in our strategy. This innovative technology helps reduce CO2 emissions and combat climate change. With our extensive experience in exploration and drilling, we are now one step closer to sustainable district heating production in Vienna.”
Potential for Green Heat for Up to 200,000 Households
The first geothermal plant developed by deeep will lay the groundwork for expanding geothermal energy in Vienna. Overall, OMV and Wien Energie plan to develop geothermal plants with a capacity of up to 200 megawatts, enabling climate-neutral district heating for around 200,000 households. The partners intend to implement up to seven geothermal plants in Vienna as part of a field development strategy, where multiple wells and plant locations are planned and constructed simultaneously for greater efficiency. The specific timeline and capacity for these additional plants will depend on the results from the pilot plant in Aspern.
Details of the Geothermal Energy Plant in Aspern
The future plant site is located on the outskirts of Seestadt Aspern/Vienna, with the well site construction expected to take about three months. During this period, the deeep project team will build access roads, prepare the necessary infrastructure, and set up construction containers, culminating in the installation of the drilling rig. An information center for residents and interested parties will also be established at the well site, with drilling scheduled to begin in winter 2024/2025.
Surface Facilities to Follow Production Tests
In summer 2025, production tests will be conducted after drilling to analyze the encountered formation water for temperature, chemical composition, and production volume. Due to its long-term isolation in rock, the thermal water in eastern Vienna is highly mineralized (e.g., salt content) and is not suitable for drinking. The findings from these tests will guide the construction of the surface facilities—managed primarily by Wien Energie in the deeep joint venture—beginning in 2026. The geothermal plant in Aspern is anticipated to commence operations in 2028.
How Deep Geothermal Energy Works
Deep geothermal energy is essential for the energy transition, reducing dependency on energy imports and providing a regional, climate-neutral energy source. As one goes deeper beneath the earth's surface, temperatures rise, with water more than 3,000 meters deep exceeding 100°C.
This hot water reservoir can be harnessed for district heating. A production pump brings formation water to the surface, where heat exchangers extract the heat for distribution through the district heating network. The cooled water is then returned to the reservoir, creating a closed renewable cycle.