GKM Mannheim

Large-Scale River Heat Pump for Mannheim Power Station

Why We Committed to the Project

The decarbonisation of heating is a vital part of Europe’s journey towards carbon neutrality. District heating systems play a central role in this transition, and harnessing renewable sources and waste heat is among the most effective ways to significantly reduce CO₂ emissions. Grosskraftwerk Mannheim (GKM) is one of the largest district heating providers in southwest Germany, supplying heat to around 120,000 households. To ensure future-proof and sustainable heating, GKM has committed to building one of the largest river heat pumps in Europe. The project forms part of a comprehensive decarbonisation plan for the Mannheim district heating network.

The system utilises the temperature difference between the river water and the district heating circuit to efficiently generate heat for thousands of households. In its first stage, the heat pump will deliver up to 20 MW of thermal power; following planned expansions, the total output will reach 100 MW. The technology we supplied ensures maximum operational safety, efficiency, and durability — even under demanding river conditions.

How We Contributed to the Project

For this landmark project, 2JCP supplied critical technological components for the heat pump system, which extracts thermal energy from the Rhine River. Our scope included the design, manufacture and delivery of large-scale steel structures and tanks that are essential for the system’s operation.

“Thanks to our long-standing experience with tailor-made pressure vessels and technological equipment for the energy sector, we were able to deliver a solution that fits seamlessly into GKM’s ambitious decarbonisation plan. We are proud that our work contributes directly to a greener and more sustainable future for the Mannheim region,” said Vojtěch Křenovský, our Group CEO.

SERVICE TANK

This is a large-scale unit: a vessel weighing 5,520 kg with a volume of 23,300 litres, requiring careful design and precision engineering.

FLASH TANK

This is a high-specification unit: a vessel weighing 5,148 kg with an operational volume of 8,920 litres, designed and manufactured in accordance with EN 13445:2021/3b and PED 2014/68/EU, Module G.

MORE ABOUT THE PROJECT

As part of the project, the river heat pump incorporates proven technology developed and manufactured in Finspång, Sweden — including a high-capacity compressor, gearbox, electric motor, heat exchangers, and an advanced control system.

The system operates like a large-scale reverse refrigerator: it extracts thermal energy from the Rhine, whose water maintains a suitable temperature range for heat extraction, and transfers it to the district heating network.

In its initial phase, the heat pump delivers 20 MW of thermal power, covering the heating needs of around 3,500 households. Once fully expanded, the system is designed to supply climate-friendly heat for tens of thousands of homes and businesses. The project is an important step towards phasing out coal and aims to deliver CO₂-neutral district heating for Mannheim by 2030, saving around 10,000 tonnes of CO₂ emissions every year.

The GKM Mannheim project also demonstrates how innovative renewable technology can strengthen local industry and energy independence. By relying on renewable electricity to generate heat, the project supports the city’s climate goals and serves as a model for other European cities transitioning to sustainable district heating.

Take a look at how the entire heat pump system was assembled on site.

Installed process tank

Visualization of the heat pump by Siemens Energy

Transport of the service vessel

Installation of the heat pump

MORE CASE STUDIES

With a strong legacy in energy products, we are constantly moving towards cleaner energy solutions.

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Delivery of special-purpose storage and process tanks for an offshore HVDC station
Sunrise Wind offshore farm, New York, USA

OUR APPROACH

We have grown through a combination of engineering know-how, courage, common sense and the proven skills of our workers. We are the bridge between thinking and making, between an idea and a multi-ton product, between our generation and the next.

Engineering and innovations

Many of our works delivered around the world were the first of their kind, whether they were components of drilling systems or green methanol production solutions. We have always tended to be co-creators of engineering solutions, never giving up on any technological challenge.

Whatever can be invented can be manufactured.

Manufacturing and delivery

Our roots are in the welding shop where it all began thirty years ago. We know well enough about steel to make it work perfectly for the energy projects of the future.

We also know that even a well-made component is useless until it's delivered, up and running. That's why we handle the entire product lifecycle - from design to go-live.