Fortum has started heat production at two large data centre sites in Finland

ONLINE NEWS 6 May 2026

Fortum’s large-scale heat pump plants in Kolabacken, Kirkkonummi, and Hepokorpi, Espoo, in the capital region of Finland have started operations. Fortum started to electrify production in its district heating network in 2014. Fortum’s strategic goal is to deliver reliable energy to our customers and drive the decarbonisation of industries and societies.

Milestone achieved: optimised heat production from different sources

Currently, the plants produce district heating with heat pumps, using ambient air as a heat source, and electric boilers. On site electric boilers together with a heat accumulator enable heat to be produced and stored when electricity is abundant and released when demand is high. Heat production will increase significantly as excess heat from Microsoft’s two data centres on the Kolabacken and Hepokorpi sites is gradually brought into use.

“The launch of sites is the result of many years of determined work,” said Peter Strannegård, Executive Vice President, Renewables and Decarbonisation. “It started seven years ago when our colleagues set out to find a data centre partner to implement a ground-breaking excess heat offtake solution, the largest in the world, together with us. It is now becoming reality thanks to the remarkable cooperation between Fortum’s committed experts, Microsoft, the cities of Espoo and Kirkkonummi, Caruna, Fingrid and all the partners who were committed to this vision.”

“Once fully implemented, data centre waste heat is expected to cover approximately 40 per cent of the total yearly 2 terawatt hour district heat demand of the 250,000 heat users in the area,” Strannegård explains.

Data centre waste heat to be integrated in phases starting next year

Data centres are essential for digitalisation, but they also represent a largely unused source of heat. In Finland and the other Nordic countries, district heating systemsare a unique infrastructure that enables the smart utilisation of waste heat. Throughout the system, most of the waste heat can be recovered and distributed across a wide area to heat commercial buildings, public spaces and homes.

The recovery of waste heat from these Microsoft data centre sites will begin step by step next year, in line with Microsoft’s construction and commissioning schedule. As new phases of the data centres are completed, increasing volumes of waste heat will be available for the district heating customers. Waste heat recovery increases local heat production capacity, reduces exposure to fuel price volatility and helps maintain predictable district heating prices.

In addition to waste heat recovery, the set-up of the plants allows heat production to respond flexibly to varying demand. The plants strengthen the reliability and price competitiveness of heat production for district heating customers in the area. For the wider energy system, flexible heat production helps balance electricity demand, particularly during fluctuating renewable generation.

Large-scale and versatile technology

The Kolabacken and Hepokorpi heat pump plants include large industrial heat pumps, electric boilers and a thermal storage facility.

• Air-to-water heat pumps: 40 units
• Water-to-water heat pumps 72 units, producing up to 180 megawatts of district heating
• Electric boiler capacity: 200 megawatts with four boilers
• Thermal storage: 20,000 m3 / 800 megawatt-hours

Investments into the heat pump plants total approximately 225 million euros. The project has been awarded European Union NextGenerationEU funding as well as investment support from the Finnish Ministry of Economic Affairs and Employment.

Towards net-zero emissions in 2040

The heat pump plants represent a concrete example of local investments that support Finland’s clean transition. As data centre waste heat is gradually integrated, Fortum plans to reduce the remaining natural gas that is used during peak demand. This is a key step in the Espoo Clean Heat programme that supports the City of Espoo’s carbon-neutrality target in 2030, as well as advancing Fortum’s ambition to reach net-zero emissions by 2040.

Fortum Corporation
Communications

Further information:
Fortum News Desk, +358 40 198 2843, newsdesk@fortum.com 
Teemu Nieminen, Director, Operations and Projects, Heating and Cooling Nordics, Fortum, teemu.nieminen@fortum.com