Here in western Germany, Evonik and Uniper are commissioning a highly innovative high-temperature heat pump to supply district heat to 1,000 households in the Ruhr region. It uses low-temperature industrial waste heat from chemical production at Evonik’s Herne site and, with pioneering technology, boosts it to a temperature suitable for district heating. As project partner, Uniper handled financing, planning, installation, and operation of the unit, with Evonik supporting execution. Through the district heating company Iqony, the heat pump feeds up to 1.5 megawatts (MW) of heat into the district heating network.
The project avoids up to 1,750 metric tons of CO2 per year in the regional heat supply—emissions that previously came from the use of fossil fuels. At the same time, supplying the heat benefits Evonik. Until now, the company has borne electricity costs for the electric fans in cooling towers that cool down heated process water from chemical production.
»Sustainable energy, security of supply, and economic success can go hand in hand.«
THOMAS WESSEL Evonik’s Chief Human Resources Officer and Labor Director
“In Herne, we’re showing together what innovative technology and partnership can make possible. Evonik and Uniper are advancing the region’s move away from fossil fuels and demonstrating that sustainable energy, security of supply, and economic success can go hand in hand,” says Thomas Wessel, Evonik’s Chief Human Resources Officer and Labor Director, and Executive Board member responsible for sustainability.
A strong signal
“With the high-temperature heat pump in Herne, we’re sending a strong technological signal: As the first facility of its kind in Germany, it shows how low-temperature industrial waste heat can be harnessed through sector coupling. For Uniper, electrifying the heating market is an important lever to support the economy with secure, affordable, and increasingly low-carbon energy on the path to decarbonization,” explains Holger Kreetz, Chief Operating Officer of Uniper. “Together with Evonik, we’re demonstrating how innovative solutions are already delivering concrete benefits for industry and municipalities.”
The new high-temperature heat pump in Herne works much like a refrigerator—but in reverse. Evonik’s production facilities in Herne require cooling water that, in the processes, warms to about 77 to 86°F (25 to 30°C). That waste heat is no longer left unused; the heat pump raises the temperature further—to the district heating network’s supply level of up to 266°F (130°C). This temperature lift of more than 212°F (over 100°C) at the megawatt scale is technically demanding—and makes the unit the first of its kind in Germany. For existing district heating networks, that is crucial: they require high supply temperatures that conventional heat pumps cannot deliver.
Integrated into the chemical plant
Is more possible?
For the companies, the project serves as a pilot. Based on the insights gained, Uniper, Evonik, and Iqony are evaluating a scale-up. In the future, it may be possible to feed in roughly another 20 MW of waste heat. “The Ruhr region has huge district-heating potential. Industrial waste heat at different temperature levels plays an important role in this. Many sources remain untapped—and we want to change that,” says Matthias Ohl, CEO of Iqony’s district heating business. He adds, “Following Gelsenkirchen and Essen, Herne is now the third waste-heat project we’ve connected to our network within just a few months. The combination of waste heat and heat pumps shows that Iqony district heating stands for a climate-friendly technology mix. Already today, around 50 percent of our heat comes from climate-neutral sources. With this pioneering project in Herne, we’re making district heating even more fit for the future.”
»Green economy: With projects like this, Herne is becoming a leading region for the green economy.«
Dr. Frank Dudda Mayor of the City of Herne
This innovative heating solution brings Evonik closer to its goal of making the production site more sustainable and climate-neutral. “As an industrial city, we continue to rely on the chemical sector as a key driver of the transformation—together with strong companies,” explains Herne’s mayor, Dr. Frank Dudda. “With projects like this, Herne is becoming a pioneer region for green industry: waste heat becomes urban heat—cutting emissions, strengthening security of supply, and bringing us closer to climate neutrality.”
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