Fortum has started operating three large heat pump plants in Kirkkonummi and Espoo, connected to the district heating network in Finland’s capital region. The facilities aim to reduce emissions while improving reliability and price stability for about 250,000 customers.
The plants use a mix of air‑to‑water and water‑to‑water heat pumps, electric boilers, and thermal storage to generate heat mainly from ambient air and electricity. Together, they include 40 air‑to‑water units, 72 water‑to‑water units (up to 180 MW of heat output), 200 MW of electric boiler capacity, and a 20,000 m3 (800 MWh) thermal storage system. The €225 million project received support from EU NextGenerationEU funding and the Finnish government.
A key feature is the planned use of waste heat from two Microsoft data centres at the same sites. As the data centres become operational, their excess heat will be added gradually and could eventually supply about 40% of the area’s 2 TWh annual heat demand. This is expected to reduce natural gas use during peak periods and support Espoo’s goal of carbon neutrality by 2030, as well as Fortum’s net-zero target for 2040.
Fortum says the project reflects years of development to integrate data centre waste heat into district heating, turning energy-intensive facilities into a local heat source.
