While Germany is still discussing the heat transition, it is a reality in Denmark. There, an entire district heating network is to be supplied by a heat pump.
Germany is discussing the heat pump. The devices are efficient, inexpensive to operate – and cause no CO2 emissions if they are powered by green electricity. They are thus at the center of the heat transition that the federal government wants to promote with the controversial heating law.
Many Germans are skeptical. Things are different in many neighboring German countries. The Scandinavian countries in particular are much further along than the Federal Republic with the expansion of the technology, and sales of heat pumps are significantly higher.
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In Denmark, people even go a step further than just heating a single house with a heat pump. In Esbjerg, an entire district heating network is to be supplied in this way – with the system from a German manufacturer.
The city on the North Sea coast has set itself the goal of becoming climate-neutral by 2030 – 15 years earlier than Germany. Electric buses drive through the city, the port serves as the largest transhipment point for offshore wind turbines, and one of the world’s largest electrolyzers for green hydrogen is to be built. The hall at the port, which houses the largest CO2-based seawater heat pump in the world, fits into the picture.
Technology from Germany
The manufacturer comes from Germany: MAN Energy Solutions (MAN ES), based in Augsburg. “The German heating market is a sleeping giant, and so far the heating transition has been slow,” said CEO Uwe Lauber recently to the “Berliner Zeitung”. Large heat pumps are the ideal technology for the heat transition. So far, however, there have only been pilot projects in Germany.
You can find out more about the German debate about the heat transition and the so-called heating law in the current t-online podcast “Discussion material”:
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The giant heat pump in Esbjerg is also a first for the company, the city’s mayor, Frost Rasmussen, told the “Spiegel”. It has an output of around 70 megawatts. A normal heat pump for private use comes to around 0.015 megawatts – the system in Esbjerg should therefore achieve 4,600 times as much.
Heat pump instead of coal power plant
The new facility aims to make Esbjerg’s carbon footprint compliant with the climate target. 60,000 tons of the greenhouse gas are to be saved annually by switching from hard coal, which previously supplied the energy for the district heating network, to the heat pump. According to “Spiegel”, this corresponds to the emissions caused by an average of 40,000 small cars with combustion engines per year.
About two thirds of households in Denmark are connected to a district heating network. The large heat pump in Esbjerg is to supply 100,000 people from October – who will therefore not have to switch to a new heating system privately.
heat from the sea
The energy comes from the sea. 4,000 liters of water per second are pumped from the harbor basin into the system, where two to three degrees of heat are extracted. Elsewhere it is diverted back, carried away by the tides and warmer water flows in. According to the operators, the system is also ecologically compatible, after all, the Wadden Sea is a UNESCO World Heritage Site and therefore strictly protected.
CO2 is used as the coolant. According to the technicians of the plant, the compression and reliquefaction in two compressors produces three times more thermal energy than is required for operation with electricity. Up to 90 degrees flow temperature arrives in the district heating network. The electricity comes mainly from wind turbines off the Danish coast – and is therefore green. In Germany, such large heat pumps are still pilot projects.
