Innovative heat and power supply through CHP plant in Duisburg

After almost two years of construction, all components of a new, modern heat and power generation plant have been completed. The innovative combined heat and power plant (iKWK plant) at the Huckingen sewage treatment plant operated by Duisburg's public utility company is now in operation. It uses the residual heat from the sewage treatment plant's treated wastewater and makes it available to supply district heating customers. The plant is the largest of its kind at a sewage treatment plant in Germany. iKWK means that a combined heat and power plant, i.e. a generation unit that produces both electricity and heat, is expanded to include an innovative component that supplies at least 35 percent of the thermal energy of the entire plant. In the case of the plant in Huckingen, this innovative component is provided by heat pumps. Two 1.9 MW units, each installed in a newly constructed building, use the waste heat from the already treated wastewater and make it usable for the district heating supply for the people of Duisburg.

"We are delighted that we are able to realize such a forward-looking and ecologically valuable project at our wastewater treatment plant together with Stadtwerke Duisburg. It shows the potential that is still too rarely used today on the way to a successful energy and heat transition," says Uwe Linsen, CEO of Wirtschaftsbetriebe Duisburg.

In addition to the heat pumps in Huckingen, the overall system also includes two hydrogen-capable combined heat and power (CHP) units and an electrical heat generator. The two CHP modules each have an electrical output of 4.5 MW and a thermal output of 4.7 MW. With this output, Stadtwerke is able to cover the annual electricity consumption of 10,000 households and at the same time supply up to 4,000 households connected to the district heating system with heat. The electrical heat generator has an output of 30 MW. It will primarily be used when there is surplus electrical energy in the grid that is not required by households or industry. This green energy potential can thus be used sensibly to generate heat instead of being left unused. In total, the local energy service provider is investing around 27 million euros in the overall project.

“This plant is also a useful addition to our generation park because we can produce heat from surplus energy, which we can store in our district heating storage facility at CHP III until it is needed by our customers,” explains Stadtwerke Infrastruktur CEO Andreas Gutschek.