The project thus avoids up to 1,750 tons of CO₂ per year in the regional heating supply—emissions that were previously generated by the use of fossil fuels. At the same time, Evonik benefits from offloading this heat. Until now, the electricity costs for the electric fans in cooling towers have been included in the energy bill. The units are used to cool down heated cooling water from chemical production.
“In Herne, we are demonstrating together what innovative technology and collaborative partnerships can achieve. Evonik and Uniper are driving the region’s transition away from fossil fuels and demonstrating that sustainable energy, security of supply, and economic success can go hand in hand,” says Thomas Wessel, Chief Human Resources Officer and Labor Director at Evonik and the Executive Board member responsible for sustainability.
“With the high-temperature heat pump in Herne, we are sending a strong technological signal: As the first plant of its kind in Germany, it demonstrates how low-temperature industrial waste heat can be utilized through sector coupling. For Uniper, the electrification of the heating market is an interesting lever for supporting the economy with secure, affordable, and increasingly low-carbon energy on the path to decarbonization,” explains Holger Kreetz, Chief Operating Officer at Uniper. “Together with Evonik, we are demonstrating how innovative solutions are already having a tangible impact on industry and municipalities today.”
The new high-temperature heat pump in Herne works in a similar way to a refrigerator—only in reverse. Evonik’s production facilities in Herne require cooling water for their operations, which heats up to approximately 25 to 30 degrees Celsius during the processes. This waste heat is no longer left unused; instead, the heat pump raises the temperature even further—to the level of the district heating network, up to 130 degrees Celsius. This temperature jump of over 100 °C on a megawatt scale is technically highly challenging—and makes the plant the first of its kind in Germany. For existing district heating networks, this is precisely what matters: they require high flow temperatures that conventional heat pumps cannot deliver.
For the companies, the project serves as a pilot: Based on the findings here, Uniper, Evonik, and Iqony are exploring scaling up the project. In the future, it may be possible to integrate an additional 20 megawatts of waste heat. “The Ruhr region has enormous district heating potential. Industrial waste heat at various temperature levels plays a key role in this. Many sources remain untapped—and we want to change that. Following Gelsenkirchen and Essen, we are now connecting the third waste heat project to our network in Herne within just a few months. The combination of waste heat and heat pumps demonstrates that Iqony’s district heating represents 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 better prepared for the future,” says Matthias Ohl, CEO of Iqony’s district heating business.
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 industry as a key driver of transformation—together with strong companies,” explains Herne Mayor Dr. Frank Dudda. “With projects like this, Herne is becoming a pioneering region for green industry: waste heat is turned into district heating—this reduces emissions, strengthens supply security, and brings us closer to climate neutrality.”
