Heat transition in Hamburg

Aurubis first had to build a new intermediate absorber. This orange-coloured colossus weighs over 250 tonnes, is 18 metres high and has a diameter of six metres. Chemical processes that take place here generate large amounts of exhaust heat that was previously cooled down in the River Elbe completely unused.

With the intermediate absorber's innovative technology, it has been possible to feed the hot water directly into the new pipeline for the HafenCity.

Aurubis manager Ulf Gehrckens was involved in the exhaust heat project from the very beginning.

“KfW made a very important contribution to this project. This project needed grants. And it was not possible to get those grants directly. There had to be a bank in between. And KfW stepped in to provide the funding.”

However, the deal wasn't perfect until KfW and the Federal Ministry for Economic Affairs and Climate Action pledged their support. Everyone agrees that without the funding, the district heating project would not have been carried out. With repayment bonuses financed by the Federal Ministry from the "KfW Energy Efficiency Programme – Waste Heat" (nowadays: "Federal funding for energy and resource efficiency in the economy"), Aurubis was able to fund the necessary plant conversion, heat extraction and internal pipeline up to the site perimeter more cost-effectively. Funding was also provided for the heat transport pipeline of the project partner Enercity

Aurubis' exhaust heat will be fed into Hamburg's 860km-long district heating network. To this end, Hamburger Energiewerke is building a new line from the future pressure heat storage system at the Georgswerder Dam to the energy delivery station on Spaldingstrasse.

More than 20,000 households will be supplied with green exhaust heat in future. Through increased use of climate-neutral industrial exhaust heat, it will be possible to save up to 100,000 tonnes of carbon emissions each year. The new exhaust heat project in Hamburg is currently one of the largest of the heating transition in Germany.

The currently largest river heat pump went into operation successfully in October 2023 in Mannheim on the Rhine. The XXL heat pump works in principle the same as a normal air source heat pump. Instead of heat from the air, the river power plant only uses Rhine water.

The water coming from the river heat pump is as hot as 99 degrees. It is part of the district heating supply operated by the Mannheim-based utility company MVV Energie AG. The river heat pump, which costs around EUR 15 million, is located on the site of the large-scale power plant in Mannheim in the south of the city. The heat goes directly into the district heating network and currently supplies green heat for 3,500 households. The planned Hamburg models will even exceed this output many times over:

Germany has set itself the goal of being climate-neutral by 2045. Around 60% of final energy consumption is currently attributable to the heating sector. The transformation of the heating sector is therefore essential. By mid-2028 at the latest, all of the around 11,000 municipalities in Germany are to have heating planning: by 30 June 2026 in large cities (100,000 inhabitants and more) and two years later in municipalities with fewer than 100,000 inhabitants. Smaller municipalities (fewer than 10,000 inhabitants) can use a simplified heat planning procedure, which is decided upon by the federal states.

The German Federal Government has laid the legal foundations for comprehensive municipal heating planning. District heating in particular will play an important role in the future heat supply: existing heat networks will be further expanded and gradually converted to supply heat from renewable energies. By 2045, all heating networks must therefore also be climate-neutral.

Since 1 January 2024, new heating networks have been required to supply at least 65% of their heat from renewable energy sources. By 2030, half of the pipeline heat is to be generated in a climate-neutral manner, with 30% of the heating in the networks set to come from renewable energies or industrial exhaust heat. By 2040, this figure is set to stand at 80%.

As the Federal Government’s digital transformation and promotional bank, KfW is making it possible for municipalities, companies and private individuals to achieve the ambitious goal of making Germany climate-neutral by 2045.

The example of Hamburg impressively shows how a municipal heating transition can be successful with targeted promotion of innovative and climate-friendly measures.