Press release

Fortum builds more flexible, electricity-based district heat production in Espoo

21 March 2024, 9:00 EET


Fortum is building new emissions-free, electricity-based district heat production in the Nuijala area of Espoo, Finland. The production plant under construction will have a 50-megawatt electric boiler and an 800-megawatt-hour heat accumulator. The electric boiler/heat storage combination will increase the flexibility of heat production and level out electricity demand by utilising time-variable electricity pricing. The construction work will begin this spring, and production is expected to start for the 2025-2026 heating season.

Increasing flexible electricity-based production is part of Fortum and the City of Espoo’s joint Espoo Clean Heat programme, during which Fortum will make district heating in the Espoo, Kauniainen and Kirkkonummi region carbon neutral by 2030. Fortum’s total capital expenditure to develop the district heating in the Espoo region amounts to approximately EUR 300 million; The Nuijala production plant’s share of this is about EUR 26 million.

The location of the Nuijala production plant is excellent due to its central location in the district heating network, as well as the availability of electricity. The plant can be used to increase the operational efficiency of the entire district heating network because it can extract heat from the electric boiler directly into the network, and the heat accumulator can be charged directly from the district heating network with CO2-free heat produced across the network. The plant will reduce the need to use the existing fossil-based peak capacity, and the heat accumulator reduces the need to invest in new peak capacity.

Water heated by the electric boiler can also be fed directly into the heat accumulator. The boiler can be used to raise the water temperature to a temperature suitable for the district heating network at times when electricity prices are low, and electricity is readily available. Heat from the accumulator is discharged when needed to cover peak demand for district heating. The thermal energy stored in the heat accumulator is equivalent to the heat consumption of about 13 000 private houses per day.

The capacity of the boiler will be phased in due to initial electricity transmission constraints. Once the Nuijala plant is in operation, it will cover about 10% of the total electricity-based district heating capacity. The commissioning of the plant will contribute to replacing the use of fossil and bio-based fuels.

In addition to the Nuijala plant, an electric boiler/heat accumulator combination is already in use in the Suomenoja plant area, and a similar combination is also under construction in the Kolabacken data centre area in Kirkkonummi. Additionally, electric boilers will be built in the Hepokorpi data centre area in Espoo. Once the waste heat recovery from Microsoft’s data centres is in full operation, district heat production will be completely carbon neutral. In 2023, the share of emissions-free district heat production was already 63 per cent.

Fortum Corporation 

Further information:

Fortum News Desk, +358 40 198 2843, newsdesk [at] fortum [dot] com (newsdesk[at]fortum[dot]com)

Tiina Davidsainen, Development Manager, Heating and cooling Finland, tiina [dot] davidsainen [at] fortum [dot] com (tiina[dot]davidsainen[at]fortum[dot]com), tel. +358 40-554 5940

Fortum is a Nordic energy company. Our purpose is to power a world where people, businesses and nature thrive together. We are one of the cleanest energy producers in Europe and our actions are guided by our ambitious environmental targets. We generate and deliver clean energy reliably and help industries to decarbonise their processes and grow. Our core operations in the Nordics comprise efficient, CO2-free power generation as well as reliable supply of electricity and district heat to private and business customers. For our ~5 000 employees, we commit to be a safe and inspiring workplace. Fortum's share is listed on Nasdaq Helsinki.