Deepwater HVDC Hits New Depths

Cable laid at 2,150 metres for Italy link as utilities push deeper offshore

2 Mar 2026

Nexans has installed a 500 kilovolt subsea high voltage direct current (HVDC) cable at a depth of about 2,150 metres for Italy’s Tyrrhenian Link, setting what the company says is a record for deepwater HVDC installation.

The 480km connection between mainland Italy and Sicily forms part of the country’s plan to modernise its transmission network and strengthen energy security. Italian authorities have sought to reinforce grid links between regions as renewable generation expands and electricity flows become more variable.

HVDC technology is widely used for long-distance and subsea transmission because it reduces power losses compared with alternating current. Deepwater routing can also improve resilience. Cables laid at greater depths are typically less exposed to ship anchors and fishing activity, lowering the risk of accidental damage and outages.

Nexans said the project demonstrates its capacity to deliver complex high voltage systems in demanding marine conditions. The group is one of a small number of manufacturers able to design, produce and install such cables using specialised vessels.

The milestone comes amid broader growth in the global HVDC market. European manufacturers including Prysmian and NKT have invested heavily in new cable-laying ships and expanded factories in recent years. Utilities increasingly prefer so-called turnkey contracts, under which a single supplier manages manufacturing, installation and long-term service.

Governments across Europe and parts of Asia have committed significant funding to upgrade transmission networks as part of climate and energy security policies. Large volumes of planned offshore wind capacity, often located far from consumption centres, depend on subsea HVDC links to connect to national grids.

Deepwater projects remain capital intensive and technically complex. Installation at extreme depths requires specialised equipment and careful planning, while regulatory approvals and environmental assessments can extend timelines.

Still, the record depth achieved on the Tyrrhenian Link underlines the shift towards more ambitious offshore infrastructure. As renewable projects move further from shore and cross-border interconnectors expand, demand for resilient subsea transmission is expected to rise.