Finland’s heat-recovery project shows why the customer for waste heat comes first
Fortum’s operating heat plants and planned Microsoft connection offer a useful lesson in sequencing digital and district-energy infrastructure.
Image: AI-generated editorial illustration, not a photograph of a specific project.
INFRADAY ANALYSIS
Waste heat has value only when someone can use it. A project taking shape in Finland makes that commercial reality unusually clear.
In May 2026, Fortum reported that its large heat-pump plants at Kolabacken in Kirkkonummi and Hepokorpi in Espoo had started operating. At that stage, the plants were producing district heat using ambient-air heat pumps and electric boilers.
The connection to Microsoft’s data centers was a subsequent milestone. Fortum said recovery of their excess heat would begin in phases in 2027, following the data centers’ construction and commissioning. The company expects recovered data-center heat eventually to cover about 40% of annual district-heating demand in the relevant service area.
That sequence is important. An operating heat plant and an operating data-center heat-recovery connection are different achievements. The planned benefit should be tracked against the point at which the data centers actually supply usable heat.
Start with the receiving network
For U.S. developers considering a similar approach, the first diligence question should concern the heat customer. Is there a nearby network, campus or industrial user able to take the output? What temperature does it require, and how does demand change through the year?
Infraday’s view is that an early feasibility study should establish those conditions before promising a community benefit. A nearby building on a site plan is not, by itself, a heat customer with a workable connection and purchasing agreement.
The parties also need to assign the cost of the link, the equipment needed to make the heat useful and the consequences of changes in either facility’s operating schedule.
Plan for two construction calendars
Fortum’s phased approach illustrates a coordination problem that any comparable proposal should address. The heat system and computing campus may not be ready together. Their agreements need to explain how the receiving customer is served during that gap.
The same discipline applies to future expansion. A heat buyer should understand how much output is committed, how much depends on later data-center phases and how interruptions will be handled.
Heat recovery can make a digital infrastructure project part of a wider local energy system. Its credibility comes from the receiving network, the operating arrangements and the delivery timetable as much as from the equipment inside the server building.
Sources: Fortum, heat production at two Finnish data-center sites, May 6, 2026.
Based on the public sources linked above, reviewed September 27, 2026. Project schedules and company commitments are attributed to their issuers; analysis and recommendations are Infraday’s.