Suomenoja production plant in transition
The Suomenoja production plant is located in Espoo, Southern Finland. The plant provides district heating to customers in three cities via a 900-kilometre-long underground pipe network. In addition, the site produces district cooling, as well as electricity to the national grid.
Several investments over the years
The Suomenoja plant has been in production since 1977. Over the recent years, several investments have been made in order to transform heating towards electricity-based heat production. At the moment, the production assets on the site include four CHP units to ensure energy supply during the coldest periods, a heat pump plant that recycles heat from treated wastewater, as well as two electric boilers and a heat accumulator for flexible heat production.
The 60 MW heat pump plant consists of three heat pumps that provide up to 25% of all the heat to customers. The 20,000 m3 heat accumulator on the site can store about 800 MWh of heat energy in water. In addition, the site hosts a 100 MW electric boiler plant that was commissioned in 2023. Together with the accumulator it can increase flexibility in production: the electric boilers can heat the district heating water during periods of cheaper power prices, and furthermore, this energy can be stored in the accumulator and released to the network when heat demand peaks.
The last coal burning unit in the network, located in Suomenoja, was closed down permanently on 28.4.2024, over a year ahead of schedule. This historical decision was enabled by the advanced electricity-based production roadmap and execution. Replacing the remaining gas-based production on the site with non-fossil energy sources is currently under investigation.
electricity production capacity
270 MW
total heat production capacity
500 MW
electric boiler capacity as part of the total heat production
100 MW
