Construction Begins on Europe's Largest River-Water Heat Pump

July 27, 2026

Source: E & M powernews

Together with the ministers of economic affairs from Berlin and Düsseldorf, the cornerstone for the large-scale heat pump in the Rhine was laid in Cologne.

The Federal Minister of Economic Affairs had also come to Cologne: Together with North Rhine-Westphalia’s Minister of Economic Affairs Mona Neubaur (Greens) and Cologne’s Mayor Torsten Burmester (SPD), CDU politician Katherina Reiche laid the cornerstone for the river water heat pump in Cologne-Niehl on July 23.
Europe’s largest facility of its kind is being built there. The investment costs total approximately 280 million euros, of which the federal government is contributing about 100 million euros. It is being built and operated by the Cologne-based utility Rheinenergie.

For Rheinenergie, this is the second-largest single investment in the company’s history. “The river water heat pump is the second-largest single investment in our company’s history,” CEO Andreas Feicht is quoted as saying in a press release.

Federal Minister of Economics Reiche emphasized the project’s significance for the heating transition. The goal, she said, is to “diversify our energy supply—using domestic energy sources such as the Rhine.” According to the company, the minister’s participation underscores the project’s importance at the federal level.

Less than 1 percent of the river water

The large-scale heat pump consists of three modules, each with a capacity of 50 MW, and will operate in conjunction with the existing gas and steam turbine plants at the Niehl site. The plant is scheduled to go into operation in 2028 and will supply up to 50,000 households with district heating; it will be integrated into Cologne’s district heating network. When electricity prices are low, the heat pump will handle heat production, while conventional plants will take over when electricity prices are high.

Technically, the plant utilizes the environmental heat of the Rhine. On average, less than one percent of the river water is withdrawn for this purpose. According to Rheinenergie, the heat is transferred to a refrigerant, which is compressed in a closed loop and reaches temperatures of more than 100 degrees Celsius. The cooled Rhine water then flows back into the river. This technology reduces greenhouse gas emissions by at least 100,000 metric tons annually.

Everllence SE is the general contractor for the project. The key components of the heat pump were already manufactured in Germany, including compressors in Oberhausen and an integral gearbox in Berlin.

“The large-scale heat pump in Cologne demonstrates the innovative strength and pivotal role of the German mechanical engineering industry in Europe’s heat transition,” said Gunnar Stiesch, Chief Technology Officer at Everllence. He added that the technology used is scalable and can therefore serve as a model for other large-scale projects in Germany and Europe.

Author: Stefan Sagmeister