Nexans reported that it has completed installation of the high-voltage subsea cable for Italyโs Tyrrhenian Link project, achieving a world-record laying depth of 2,150 meters for a 500 kV HVDC connection.
A press release said that the depth record was reached during offshore operations in December 2025 and confirmed with the final pull-in on Jan. 1, 2026. The second pull-in operation established the physical connection between Terra Mala in Sardinia and Fiumetorto in Sicily, marking completion of all high-voltage subsea cable installation on the western section of the project.
The Tyrrhenian Link is being developed by Italian transmission system operator Terna S.p.A.. The project is a 500 kV HVDC interconnection designed to strengthen Italyโs electricity grid by linking Sardinia, Sicily, and the mainland.
Nexansโ scope covered the western section between Terra Mala and Fiumetorto, totaling approximately 480 km of deep-water cable installed in two campaigns of roughly 200 km and 280 km. The overall project consists of two 500 kV HVDC subsea links, each about 970 km long, with a total transmission capacity of 1,000 MW.
The installation was carried out by the Nexans Aurora, where crews managed the controlled descent of the cable to depths exceeding two kilometers across steep seabed terrain. The work required detailed bathymetric mapping, route optimization, and precise tension control, along with real-time coordination among survey teams, remotely operated vehicle (ROV) operators, and vessel crews.
โInstalling a 500 kV HVDC cable at these depths requires exceptional precision and discipline across engineering, manufacturing, route preparation and vessel operations,โ said Pascal Radue. โThese milestones reflect the strength of our technology, the performance of the Nexans Aurora, and the expertise of our teams throughout the project.โ
Giuseppina Di Foggia said the achievement supports Italyโs long-term energy objectives. โThe Tyrrhenian Link has reached a depth of 2,150 meters, setting a world record for a submarine power cable. This milestone demonstrates Ternaโs ability to manage highly complex technological challenges and deliver infrastructure that strengthens the stability, security and adequacy of Italyโs electricity system.โ
According to Nexans and Terna, completing the installation at record depth without incident expands the technical limits for deep-water HVDC systems and establishes a new benchmark for future subsea transmission projects.
Large-scale subsea transmission projects continue to expand the technical boundaries of high-voltage cable systems. Many of these developments are covered in the Industry News section on Wirenet.
High-voltage direct current (HVDC) technology plays a critical role in long-distance power transmission and offshore energy integration. The Wire Association International also provides education and technical resources supporting advancements in power transmission systems.
Other important WAI links:
- Industry News โ https://wirenet.org/industry-news/
- HVDC / technical resources โ https://wirenet.org/technical-papers/
- WAI Education โ https://wirenet.org/education/
