The installation at the waste incineration plant in Spitlau – at a cost of €40 million – is scheduled for completion in 2025.
Wien Energie is building a large heat pump system with an output capacity of 16 MW at the Spitlau waste incineration plant in Vienna. This will then “warm up” 16,000 households from 2025. “Achieving our climate goals and providing Viennese residents with reliable heat is our top priority,” the responsible city councilor Peter Hanke was quoted as saying in a statement issued by the energy supplier on Wednesday.
“By building this new large-scale heat pump, we are taking another big step toward a climate-neutral future for our city,” Hanke said. “Spitelao has long championed environmentally friendly heating supplies, and is now heating more homes sustainably.” Wien-Energie Managing Director Karl Gruber: “By investing around €40 million in this highly innovative solution to make the most of existing waste heat, we are at the forefront of technology and setting standards across Europe.” The increase in the efficiency of the waste incineration plant is about 13 percent, bringing the total efficiency to 95 percent.
We want to be climate neutral by 2040. The importance of district heating is growing rapidly. It is expected to cover 56% of Vienna’s heating needs by 2040. In order to generate district heating exclusively in a climate-neutral way in the future, geothermal energy will also be used and existing waste heat used. For example, Wien Energie cooperates with OMV.
Electricity and heat are generated at the waste incineration plant in Spitlau. Flue gases are produced during the combustion process. It is filtered and cleaned in a multi-stage process, including so-called wet flue gas scrubbing. Pollutants from flue gas are associated with water. The water is then cleaned in a complex process, cooled and released back into the Danube Canal as pure water. The waste heat remains in the flue gas and is released into the air through the chimney.
This will change from the beginning of 2025: in the future Wien Energie will use this waste heat to generate additional district heating using heat pumps. Vienna uses heat exchangers to extract about 10°C of energy from the condensate (water) created when the flue gas is cooled. Wien Energie can use this energy with modern heat pump technology in a very complex system to generate heat at around 90 degrees Celsius. This heat then flows in the form of hot water through the central heating network to tens of thousands of apartments in Vienna, which Wien Energie supplies with central heating.
The cooled water from the flue gas condensation is then treated by Wien Energie and returned to the waste incineration process. As a result, Wien Energie uses up to 125,000 cubic meters of water per year less than the Danube Canal for its waste incineration process, which is approximately the same amount of water as 700,000 bathtub fillers (apa).
Photo: Wiener Stadtwerke