Wien Energie and OMV have reached a major milestone in their deep geothermal project in Aspern, bringing Vienna closer to year-round, climate-neutral heat generated locally for the city.
From autumn 2025, formation water was brought to the surface for the first time from a depth of around 3,000 meters and then returned to the deep underground as part of a closed-loop test. According to the companies, the results significantly exceeded expectations. The planned facility could supply climate-neutral district heating to around 25,000 average Viennese households, about 5,000 more than originally planned.
OMV and Wien Energie had expected to extract formation water at about 100 degrees Celsius. During testing, temperatures of 104 degrees Celsius were measured. The available flow rate also gave the companies reason for optimism. The originally forecast thermal output of 20 megawatts could be clearly exceeded, with the plant now expected to reach about 25 megawatts.
At that capacity, Vienna’s first deep geothermal plant could provide heating and hot water for around 25,000 households. The companies said the new figures go well beyond already ambitious forecasts and confirm the potential of deep geothermal energy for heat generation in Vienna.
The Aspern plant is located at Seestadtstraße 17 in Vienna’s 22nd district. Its planned output is about 25 megawatts thermal, including heat pumps from Wien Energie. The planned investment volume is around 90 million euros. The project is supported by environmental funding from Austria’s climate protection ministry, the Climate and Energy Fund, and the European Investment Bank.
