A 70-meter tower holding enough heated water to warm 30,000 homes through a cold winter day is coming to Malmö. Bilfinger has been awarded a contract by E.ON to engineer, prefabricate, install, and commission a 2,400 MWh district heating accumulator — the largest single investment in the city’s district heating infrastructure in years. The facility is projected to cut CO2 emissions from district heating production by up to 50 percent. Engineering is set to begin in late May 2026, with commissioning targeted for winter 2028/2029.
Contract Details and Facility Specifications
The accumulator Bilfinger will build for E.ON is not a modest upgrade. Rising approximately 70 meters — roughly the height of a 20-story building — it holds around 45,000 cubic meters of heated water, translating to a storage capacity of approximately 2,400 MWh. That is enough thermal energy to keep around 30,000 households warm on a cold winter day.
E.ON and Bilfinger describe this as the largest single investment in Malmö’s district heating infrastructure in many years. The framing underlines how significant the facility is — not just in scale, but in what it signals about the city’s long-term approach to energy planning.
Why E.ON Selected This Technology and Contractor
The accumulator relies on Hedbäck technology, a pressureless design with an established track record in the district heating sector. Pressureless systems are considered efficient for large-scale thermal storage because they simplify engineering requirements while maximizing usable storage volume.
Bilfinger was selected to handle the full project scope — engineering, prefabrication, installation, and commissioning. That end-to-end responsibility reduces coordination risk and keeps quality control under a single contractor. Prefabrication will take place at Bilfinger’s workshop in Gródek, Poland, where manufacturing key components in a controlled environment typically improves consistency and compresses on-site delivery timelines.
Expected Emissions and Energy System Impact
The most notable figure attached to this project is the projected emissions reduction: CO2 output from district heating production in Malmö could fall by up to 50 percent once the accumulator is operational. That is a substantial result for a single piece of infrastructure.
The mechanism is flexibility. A large accumulator allows heat to be produced when conditions are optimal — when renewable energy is abundant and cheap — and stored for use when demand peaks. This decoupling of production from consumption means the system does not need to activate carbon-intensive backup sources during high-demand periods, smoothing out the spikes that tend to push both costs and emissions higher.
That same flexibility strengthens the overall resilience of Malmö’s energy supply. Operators can draw on stored heat rather than scrambling to match production to demand in real time. Large-scale thermal storage is increasingly viewed as a practical, cost-effective tool for cities working to integrate more renewables into their heating networks, and this project fits squarely within that trend.
Project Timeline and Broader Strategic Context
Engineering is scheduled to begin at the end of May 2026, with commissioning targeted for winter 2028/2029 — roughly two and a half years from start to a fully operational facility. That timeline reflects the genuine complexity of designing, prefabricating, and installing a structure of this size.
The contract is one component of a larger initiative. E.ON is developing Malmö’s Northern Harbour as a new energy cluster, with the accumulator intended to anchor a center for modern, lower-emission infrastructure across the city. It is not a standalone project — it is a building block.
Across Europe, the pattern is similar. As cities and utilities work to decarbonize heating networks, large-scale thermal energy storage is drawing growing investment. District heating systems once built around steady fossil fuel combustion are being redesigned for variable renewable sources, and accumulators are proving central to making that shift work in practice.
CO2 Emissions Reduced by 50%
Bilfinger has been awarded a contract by E.ON to deliver a 70-meter, 2,400 MWh district heating accumulator in Malmö, Sweden. The facility will hold 45,000 cubic meters of heated water and is projected to reduce CO2 emissions from district heating production by up to 50 percent. It uses Hedbäck pressureless technology and will be prefabricated at Bilfinger’s facility in Gródek, Poland. Engineering starts in late May 2026, with commissioning expected in winter 2028/2029. The project is part of E.ON’s development of Malmö’s Northern Harbour energy cluster and represents the city’s largest single district heating investment in many years.
