E.ON, SIGNA and Berliner Wasserbetriebe are starting the energy transition from below at Berlin-Ostbahnhof: The former “Galeria Kaufhof” at the Koppenstraße in Berlin has been transformed into a modern office building (50,000 m²), which is now sustainably supplied with heat and cold from wastewater. This is made possible by a 200-meter-long heat exchanger in the sewer next to the building.
"This way, we cover around 50 percent of the heating and cooling needs of the building in a sustainable way and save around 400 tons of CO2. This energy plant in the middle of Berlin is a prime example of the efficient use of local energy sources," says Nikolaus Meyer, Head of Solution Development at E.ON.
"With our projects, we want to make our contribution to combating climate change and consistently plan our projects with regard to their environmental sustainability," says Reiner Müller, Head of Project Development at SIGNA Real Estate. "By retaining the existing structure and using state-of-the-art heating and cooling technology, we achieve an excellent CO2 balance at the UP!"
The heat supply of cities is a central lever for achieving the climate targets and thus for a successful energy transition. A large part of the energy in Germany, almost 1,220 terawatt hours (TWh), is used in the heating sector. But so far, only 15 percent of the energy required comes from renewable sources. In Germany alone, energy generated from wastewater could mathematically cover 14 percent of the heat demand in the building sector and be used equally for cooling.
"Wastewater heat is a component of the energy transition of the Berlin heating sector. The innovative potential-atlas of the water companies shows that 586 kilometres of the sewer and wastewater pressure networks in Berlin are suitable for using this technology," says Alexander Schitkowsky, project manager of Berliner Wasserbetriebe. "We want to make use of this and develop the technology further together with partners such as E.ON and Signa."
Wastewater has a year-round constant temperature of up to 20°C. This heat is normally released unused into the surrounding soil. This is not the case in Koppenstraße: here, a 100-year-old gravity sewer with a diameter of two metres is used for the heating and cooling supply of the office building. This enables a withdrawal power of more than 600 kilowatts (kW).
A stainless-steel heat exchanger extracts the existing heat from the wastewater, after which a large heat pump increases the temperature of the heat generated and heats the building. In the summer, the principle is reversed, and the channel can be used as an efficient source of cooling. In addition, a combined heat and power plant is used for a highly efficient and affordable supply of electricity, a cooling system and a gas condensing boiler.
In addition to increasing demands on environmental and energy supply standards, urban planning solutions must also remain stable when it comes to costs. The energy supply solution with the wastewater heat exchanger is as cheap as a conventional solution with fossil-generated district heating. A decentralized, space-saving energy supply from wastewater enables sustainable heat and cold in the middle of the city, where space for wind and solar energy is usually limited.
This press release may contain forward-looking statements based on current assumptions and forecasts made by E.ON Group Management and other information currently available to E.ON. Various known and unknown risks, uncertainties, and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. E.ON SE does not intend, and does not assume any liability whatsoever, to update these forward-looking statements or to align them to future events or developments.