Hepokorpi-Finnoo underground cabling project
The most significant electricity network construction project in Espoo in 2026–2028
The Hepokorpi–Finnoo 110 kV underground cabling project will enable a strong and reliable electricity transmission connection from the national grid to meet the needs of southern Espoo and its growing customer base. At the same time, the Finnoo substation—one of the most important nodes in the regional electricity network—will be renewed. The project will be implemented between 2026 and 2028.
The implementation of the cable route in this specific manner is the result of collaboration carried out between 2022 and 2025. Dozens of different stakeholders, including the City of Espoo, have participated in the planning process.
Overall, Caruna will invest approximately EUR 80 million in the high-voltage electricity network in the Espoo area (substations and transmission lines) during the current decade.
Project implementation and schedule
Key stakeholders
- The project developer is Caruna Espoo Oy.
- The construction of the cable route will be carried out by Hyvinkään Tieluiska Oy. Tieluiska is an experienced contractor specializing in demanding infrastructure projects and is also well known in Espoo as a supplier for several different projects.
- The contractor responsible for the cable installation will be selected in summer 2026.
Project schedule
- In the initial phase (summer 2026 – winter 2027), construction will focus solely on the cable route. This includes the excavation of the cable trench, installation of protective conduits for the cables, backfilling and other protective structures, as well as final or temporary surface works and finishing.
- Once the route construction has progressed sufficiently, the electrical works will commence in spring 2027. This phase includes installing the cables into the completed conduits and carrying out jointing works.
- The cable route will be largely completed during 2027, and the electrical works are scheduled to be completed in summer 2028.
Provide feedback on the project
We welcome constructive feedback related to the practical implementation of the project. However, before submitting feedback, we kindly ask you to take the following points into consideration:
- The final route is always a compromise between numerous different needs, objectives, and other important societal projects and plans.
- All infrastructure projects cause temporary inconvenience to residents. We apologise for this and ask for your patience.
- The contractors responsible for the practical implementation of the project do their best to carry out the work efficiently while maintaining high quality. Efforts are made at the construction site to minimise disruption, but it cannot be completely avoided.
Developing the high-voltage electricity network
Caruna Espoo Oy is responsible for the operation and development of the electricity network in Espoo, Kauniainen and Kirkkonummi during a period of rapid energy transition. A reliable electricity network is one of the cornerstones of a well-functioning society. The high-voltage electricity network enables the transmission of electrical energy from the national grid to the main consumption centres in urban areas.