Nexans Sets Record with Deepest-Ever HVDC Subsea Cable Installation

(Credit: Nexans)

French cable maker Nexans has set a new world record in the subsea power cable industry after installing a 500 kV high-voltage direct current (HVDC) subsea cable at a depth of 2,150 meters on Italy’s Tyrrhenian Link project.

The installation, completed during the holiday period, marks the deepest-ever deployment of an HVDC subsea power cable and was carried out in collaboration with Italian grid operator Terna.

The milestone was achieved on the western section of the Tyrrhenian Link, a major electricity interconnection project linking Sicily and Sardinia, and reflects years of engineering development and operational capability, the company said.

Once completed, the Tyrrhenian Link will consist of two 500 kV HVDC subsea cables with a total length of about 970 kilometers and a transmission capacity of 1,000 MW. The connection between Sicily and Sardinia alone will span roughly 480 kilometers and reach depths of up to 2,150 meters below sea level.

Terna is investing around $4.3 billion in the project, which also includes an eastern section linking Sicily and Campania, where installation of the first cable was completed in May.

Cable-laying work on the western section is being carried out by Nexans in two phases, with the first phase completed in September 2025 and the second phase beginning in December 2025.

The Tyrrhenian Link has been described as a strategic project for Italy’s power system, aimed at strengthening grid security, increasing transmission capacity between regions and supporting the country’s decarbonization targets under its national energy and climate plan.

In addition to its technical scope, the project includes environmental measures at cable landing points and converter station sites, including marine habitat protection and vegetation replanting initiatives.