Helsinki reconciles electricity consumption and ecological transition
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Omexom is set to build Finland’s first and largest 400 kV cable connection. It will supply double the electricity while replacing coal-fired power plants with heat pumps. The project’s urban setting only adds to the challenge.
In collaboration with the City of Helsinki, Distribution System Operator Helen Sähköverkko and the Finnish Transmission System Operator Fingrid are creating a new connection to the capital city’s primary network, in order to meet growing electricity consumption in the region and promote ecological transition. This new connection boasts several notable features: it involves a 400,000-volt underground cable connection, total 12 kilometres in length.
“Until now, Helen has been using coal-fired plants to produce electricity and heat for central heating systems,” explains Ilmari Koikkalainen, Project Manager at Omexom Finland. “But it has now decided to close them in order to reduce its CO2 emissions – the Hanasaari plant closed in 2023, with Salmisaari due to follow suit in April 2025.” However, the city’s electricity consumption will continue to increase as its population grows and its transportation and heating systems are electrified. As it turns to heat pumps, Helen will require considerably more electricity, hence the need for a 400 kV cable connection.
Double the electricity for Helsinki
This new connection will make it possible to supply Helsinki with double the electricity and complete Western Boulevard City, a project for a new district designed to provide housing, transport connections and services to some 14,000 residents in the area around the Vihdintie and Huopalahdentie routes, northwest of Helsinki. Once the cable connection is completed, the high-voltage 110-kilovolt overhead lines running along Vihdintie will be replaced by underground lines.
“The main challenges posed by this project are the volume and size of the cabling, and the urban environment with its wide variety of settings”
“Project planning for the cable link started in 2020,” explains Ilmari Koikkalainen, who is working on the project. “Then, the on-site works will begin in April 2025 for completion in the summer of 2026. The civil engineering work has been ongoing for around a year, and fabrication of the cables began in summer 2024.” Omexom Finland is responsible for construction of the connection as a contractor for the cable manufacturer Demirer Kablo, which is Fingrid’s main contractor on the project. Omexom also played its part in the design phase, providing a set of recommendations for cable route and jointing sections.
“The main challenges posed by this project are the volume and size of the cabling, and the urban environment with its wide variety of settings,” says the project manager. “We will be transporting 89cable drums from the Port of Vuosaari to various site locations across the urban area.”
Solid local experience
Omexom brings its solid local experience in high-voltage cabling, particularly in the area of HSEQ (health, safety, environment and quality) and familiarity with the end customer, Fingrid, to this project, which is likely to cost over €100 million, “This is the main reason a foreign company like Demirer Kablo chose Omexom as a partner,” suggests Ilmari Koikkalainen.
Omexom hopes its expertise will prove useful in the future, since Fingrid intends to continue its policy of low-carbon transition in the production and consumption of energy for the Helsinki metropolitan area. “We hope to be their partner in their future 400 kV underground cable projects,” concludes Ilmari Koikkalainen.
04/17/2025
