Image source: Nexans

Nexans has installed and tested a 525 kV mass-impregnated (MI) high-voltage direct current (HVDC) subsea cable at a depth of 3,000 meters off the coast of Sicily, Italy. The cable was tested 30% above industry standards to confirm reliability under extreme conditions, setting a new depth record for subsea HVDC technology.

This follows a December 2025 installation of an MI HVDC cable at 2,150 meters for the Tyrrhenian Link project in Italy. Both operations demonstrate the technical demands and precision involved in deepwater cable installation and testing.

The 3,000-meter depth is roughly equivalent to seven stacked Empire State Buildings, illustrating the scale and complexity of the project. According to Nexans, these milestones reflect decades of experience in subsea HVDC systems and specialized engineering expertise.

The record highlights recent developments in subsea high-voltage transmission and the engineering required for long-distance underwater power connections. These advances are important for offshore energy projects and integrating renewable energy into wider electrical grids.

Source: Nexans