Nexans to start repairing damaged Finland-Estonia subsea link next month

Nexans has been tasked to carry out subsea cable repair on the electricity transmission link between Finland and Estonia that was damaged at the end of December 2024, with the activities set to begin in May and the link expected to start operating again in July.

To remind, Finnish transmission system operator (TSO) Fingrid reported to the authorities on December 25, 2024, the failure of Estlink 2, prompting an immediate investigation into the chain of events of the incident as well as whether a foreign ship was involved in the damage.

A day later, Finland seized the Cook Islands-flagged tanker Eagle S, which, according to initial reports, may have had an unsecured anchor, on suspicion that the vessel caused the outage and damaged internet lines. Photos of the vessel showed that the hull had been damaged.

Fingrid reported that the actual repair work on the electricity transmission connection will begin next month, expected to take two months.

After the repair work and tests ensuring the functionality of the cable connection have been completed, the interconnector will return to commercial use, planned for July 15.

Preliminary work has already been performed during February and April, with the goal of reducing the risks associated with the actual repair work and helping refine the details of the actual repair plan. The damaged section of the cable was excavated and cut out at sea for further examination, and the remaining cable sections were tested for integrity.

“A new cable is being installed on the seabed to replace the existing one over a distance of approximately one kilometer. Implementing such extensive repair work has required detailed planning and necessitates a specially equipped vessel for the task. The repair work has been planned and prepared since January in close cooperation with Nexans, the company carrying out the work,” said Fingrid’s unit manager Kimmo Nepola.

Estlink 2, officially launched in 2014 with a capacity of 650 MW, is 170 kilometers long, of which 145 kilometers is submarine cable, 14 kilometers overhead on the Finnish side and 12 kilometers underground in Estonia.

This was not the first time Estlink 2 had been shut down in 2024. Namely, the link was shut down in the first hour of January 26, 2024, due to a fault located in “a geotechnically demanding area” on the Estonian coast, which kept it out of operation until August 31.

A couple of months later, a fault was detected in the first electrical connection between the two countries. Estlink 1 was out of service due to a technical fault at the converter station in Espoo. The electrical connection was switched off at 4:26 a.m. on March 9 on the Finnish side, while the power cable remained intact. Operational since 2006, the link has a capacity of 350 MW.

Fingrid and its Estonian counterpart Elering signed a memorandum in June 2022 agreeing to start work on the establishment of Estlink 3. In the summer of 2024, Estonia’s Consumer Protection and Technical Regulatory Authority (CPTRA) initiated the building permit procedure for what will be the third electricity connection between the two countries.