Helen has selected YIT and ACCIONA, as alliance partners for a tunnel system in a seawater heat recovery project in Salmisaari, Helsinki. The cost estimate for the construction of the tunnel system is approximately EUR 400 million, of which YIT's share is for about half. The work will start with a two-year development phase, for which a contract will be signed, and the project will be included in the order book during the third quarter of 2022.

The implementation phase of the contract will be added in the order book once the implementation phase alliance contract is signed approximately in autumn 2024. Work will start after the end of the appeal period in July 2022, and the development phase is expected to last until autumn 2024. At the end of the development phase, a decision will be taken to move to the implementation phase, which will last approximately five years.

The seawater heat recovery project will supply seawater all year round to the heat pumps to be built in Salmisaari. The heat pumps will use even less than +2 degrees Celsius seawater and electricity for district heating production. Produced heat is delivered to customers via the district heating network.

In addition, during the summer, heat pumps can be used to produce cooling energy for the district cooling network. The heat from seawater is renewable, and the heat source is inexhaustible. Supporting carbon-neutral heat production, the seawater heat pumps are designed to be located in the Salmisaari power plant area.

Heat pumps that utilise ambient and waste heat play a key role in Helen's target of achieving carbon neutrality by 2030.