The Fortum EcoHeat district heating service - Fortum Oyj bets on low-carbon flexibility

The Fortum EcoHeat district heating service starts quietly at 5 a.m., when a warm hiss rises from basement radiators in Espoo and the smell of coffee drifts through stairwells. For Fortum’s head of City Solutions, Tuomas Haapala, this is the sound of a low-carbon business model humming in the background.

Low-carbon heat for Espoo

EcoHeat is Fortum’s branded district heating service in southern Finland, focusing on Espoo, Kauniainen and Kirkkonummi, where the company supplied about 800 GWh of heat in 2023. Fortum is shifting this network away from coal and natural gas toward waste heat, biomass and other low-carbon sources as part of its 2030 sustainability targets.

The backbone today still includes the Suomenoja combined heat and power plant, but Fortum has started replacing coal-fired capacity with heat pumps that recover waste heat from sources such as data centers and wastewater. In Espoo, the company has signed deals with firms like Microsoft to capture excess data-center heat and feed it into EcoHeat pipes under residential streets.

From coal exit to circular heat

According to Fortum’s 2023 Sustainability Report, the utility cut direct CO? emissions in Espoo district heating by around 40 percent between 2017 and 2023 as it progressed with coal exit plans. President and CEO Markus Rauramo has framed EcoHeat as a showcase for how existing urban infrastructure can become part of a circular energy system.

One visible piece of that system is the Kakola heat pump plant in Turku, operated by Fortum’s partner Turku Energia, which recovers heat from wastewater and channels it to district heating customers. While not branded as EcoHeat locally, Fortum highlights Kakola as the kind of high-efficiency heat pump technology it is replicating in its own networks.

How EcoHeat earns its money

EcoHeat’s business model is straightforward: Fortum charges heat customers a fixed connection fee and then variable energy charges based on consumption measured at the building’s heat exchanger. Prices are regulated at the municipal level but reflect fuel, electricity and investment costs, so tariff adjustments can be sensitive for local politics.

A typical residential building in Espoo connected to EcoHeat might use 15 to 20 MWh of district heat per year, with Fortum’s published price examples implying annual heating bills of roughly 1,000 to 1,400 euros for an average apartment block, depending on insulation and weather. For Fortum, these predictable volumes translate into stable cash flows that appeal to infrastructure investors watching the Fortum Oyj stock.

EcoHeat is not just a winter product. In many newer connections Fortum delivers district cooling alongside heating, using the same underground pipe network and absorption chillers fed by waste heat or industrial surplus. Office towers in Espoo’s Keilaniemi district depend on this combo to keep glass facades comfortable in summer without noisy rooftop chillers.

Microsoft data centers and waste heat

One of the most talked-about EcoHeat projects is Fortum’s partnership with Microsoft to use waste heat from planned data centers in Espoo, Kirkkonummi and Kauniainen. The companies estimate that recovered heat could cover up to 40 percent of the area’s district heating demand once fully implemented.

Fortum’s City Solutions team, led by Executive Vice President Tuomas Haapala, has described walking through the humming server halls as “standing next to a concentrated heat source that used to be pure waste”. Instead of venting that heat into the air, large industrial heat pumps raise the temperature and push it into the EcoHeat network, where residents feel it as gentle warmth in bedroom radiators.

Regulation, risk and customer optics

District heating is a regulated utility in Finland, and EcoHeat operates under local energy regulations and environmental permits overseen by authorities like the Regional State Administrative Agencies. Fortum must manage noise limits, thermal pollution in receiving waters and safety standards around high-temperature equipment. These rules add cost but also create barriers to entry that protect established operators.

Customer optics matter too. Fortum publishes regular updates on price changes and environmental performance to reassure households that EcoHeat aligns with Finland’s climate goals. In 2023, the company reported its Espoo-area district heating emissions intensity at roughly 90 g CO? per kWh, significantly below EU-28 averages for fossil-based heat, as the share of waste heat increased.

EcoHeat in Fortum’s portfolio and stock

In Fortum’s segment reporting, EcoHeat sits within the City Solutions business, together with other district heating operations in Finland and Poland. While not the largest profit contributor compared with Nordic electricity generation, this unit supplies recurring earnings and underpins Fortum’s narrative as a decarbonizing utility focused on stable, regulated assets.

For holders of the Fortum Oyj share watching Helsinki’s stock exchange, EcoHeat is less about sudden growth and more about long-term resilience: tariff-indexed revenues, infrastructure backed by municipal demand, and a platform for future electrification and heat pump rollouts. On Nasdaq Helsinki, Fortum Oyj stock trades in euros and reflects investor expectations about this combination of low-carbon transition and cash generation.