River heat pump Cologne-Niehl

Designing for a new energy future

In Cologne, the intake structure for Europe’s largest river heat pump is being built at the Cologne-Niehl port on the Rhine. Zentrale Technik made key contributions to the design during the early stages of the project – particularly in developing the excavation solution and coordinating complex technical interfaces.

To generate sustainable energy, the massive civil engineering structure will in future draw water from the Rhine and feed it to the river heat pump via a pumping and piping system.

At the heart of the project is a watertight excavation pit with a partition wall separating it from the adjacent harbour basin – a technically challenging feat, as the structure is being built directly behind an existing, back-anchored sheet pile wall. The unique feature is that the excavation pit itself will form part of the finished structure – the reinforced concrete stiffening belt will later serve as a component of the outer wall of the structure.

In addition to the technical function – supplying the large heat pump with river water – ecological requirements were also taken into account: a fish return system, comprising a lifting mechanism and a fish ladder, is integrated into the system. 

Design expertise under unique circumstances

The challenge of this project lies less in the height of the structure than in the depth of coordination required: the significant emphasis on building services engineering – in collaboration with a local energy supplier acting as the client – necessitated close integration between structural engineering, civil engineering and building services engineering. Zentrale Technik is responsible for the technical development of the excavation solution as part of the tender preparation process, as well as for cross-disciplinary coordination within the consortium.

Engineered to perfection to create Europe’s largest river heat pump

The planned sequence is particularly well thought out: preliminary excavation with residual water retention allows the excavation pit to be stiffened under dry conditions. The watertight retaining wall is designed as a combination of an interlocking bored pile wall and a soldier pile wall – partly back-anchored, partly braced, with a waterproof concrete base below the waterline. The early involvement of ZT – particularly in the areas of civil engineering, structural engineering, building services and structural design – plays a decisive role in delivering a technically and economically sound overall solution for the construction of the river heat pump.