Helsinki 400 kV Underground Power Cable Project

Kontrakt for 400 kV kabel

Omexom Finland was awarded the contract in early 2024 by Demirer Kablo to execute Fingrid’s first 400 kV underground power cable project connecting the Länsisalmi and Vanhakaupunki suburbs in Helsinki. The project involves full site management, HSEQ oversight, cable pulling, accessories installation, and engineering support including route and jointing section design, with a collaborative approach alongside civil contractors and other stakeholders.

Viktig for Helsinkis energiomstilling

This 12-kilometer high-voltage cable line is critical to Helsinki’s energy transition, replacing outdated 110 kV overhead lines and enabling the city to phase out coal-fired power plants. With district heating and electricity demands rising due to the closure of Hanasaari in 2023 and Salmisaari in 2025, the underground cable supports a shift to electric heat pump technology and future urban developments such as the Western Boulevard City designed for 14,000+ residents.

Utfordringer og fremdrift på plass

The construction faces challenges related to the large size and weight of the 400 kV cables, logistics of urban site work, handling 89 massive cable drums transported from Port of Vuosaari, and rainy summer conditions affecting site water management. Despite these, the project remains on schedule with 65% complete by late August 2025, targeting October 2026 for completion and final acceptance by February 2027.

Miljøvennlig utstyr reduserer utslipp

Environmental sustainability is emphasized through the use of electric-powered machinery, including a battery unit replacing diesel generators and an electric cable drum trailer, reducing emissions and noise pollution on-site. This project sets a benchmark for future underground high-voltage cable projects in Finland, reflecting advanced innovation and strong partnership between Omexom and Fingrid.