Important contribution to the goal of climate neutrality by 2040
Wien Energie has already been building the most powerful and environmentally friendly large-scale heat pump plant in Europe, which utilises waste heat from a sewage treatment plant, on the site next to the ebswien sewage treatment plant for one and a half years. Wien Energie has invested around
70 mio. euros in the construction of the first stage of the plant.
"Vienna will be climate-neutral by 2040", said Mayor Michael Ludwig on the completion of the plant. "The heat pump system at the sewage treatment plant is a major milestone on this path. As a city, we are turning the big screws and utilising every renewable heat source available to us. With this new Wien Energie plant alone, we can already supply up to 56,000 Viennese households with green district heating in the first expansion stage. With our heat pumps, we are pioneers throughout Europe", continues Ludwig.
100 per cent regional and renewable energy
The plant uses the treated wastewater from the neighbouring ebswien sewage treatment plant to generate heat. The heat in the wastewater, which previously flowed unused into the Danube Canal, can thus be put to good use.
Normally, the wastewater from the sewage treatment plant flows into the Danube Canal after purification. From now on, the water will take a diversion into the large heat pump system before it reaches the canal: this is where the heat pumps are located, which use heat exchangers to extract around 6 °C from the purified water. Wien Energie can utilise this low temperature with the modern technology in the highly complex system to generate heat at more than 90 °C. This heat then flows out in the form of hot water. This heat then flows in the form of hot water via the district heating network to tens of thousands of Viennese homes that are supplied with district heating.
With electricity from the nearby Freudenau power plant on the Danube and waste heat from the sewage treatment plant's wastewater, Wien Energie can operate the large heat pump using 100 % renewable energy. However, it is not only the waste heat from the wastewater that is used to generate sustainable energy at the sewage treatment plant, but also the wastewater, sewage sludge, hydropower and solar energy.
Wien Energie obtains the green electricity required to operate the plant directly from the nearby VERBUND Danube power plant in Freudenau. To ensure efficient and optimised operation of the heat pump, Wien Energie has built its own direct line between the power station and the plant. A separate junction was built at the power station for this purpose.
Distribution in the district heating network through a new pumping station
Wien Energie has also built a new district heating pumping station in order to be able to distribute these large quantities of heat in the district heating network. There is now a second pumping station at the Simmering power plant site, which - like a heart - pumps up to 7,500 m3 of hot water per hour through the district heating network.
This new pumping station can not only distribute the heat from the heat pumps at the sewage treatment plant, but also other capacities. This is necessary as the district heating network in Vienna is constantly growing. Today, Vienna's district heating network is one of the largest in Europe with a length of over 1,300 km.
Wien Energie supplies 440,000 Viennese households and 7,800 large customers with district heating. Wien Energie aims to supply around 56 % of Viennese households with climate-neutral district heating by 2040.
"We are writing a piece of heating transition history for Vienna here. With the first expansion stage of the large heat pump, we are increasing the proportion of renewable district heating by around 7 %. When fully expanded, we will double the output and will be able to supply over 100,000 Viennese households with climate-neutral and regional heat," explains Michael Strebl, Chairman of the Wien Energie Management Board. In a next step, the three heat pumps currently installed will be joined by three more systems by 2027. When fully expanded, Wien Energie plans to generate district heating with a capacity of 110 MW at this location in future.
(Quelle: Wien Energie)
