Subsea interconnection

Nexans CLV Skagerrak

Subsea interconnections: joining forces to promote the energy transition

The all-electric age is just around the corner. It will involve transmitting more renewable electricity worldwide and ensuring the reliability of power grids. In response to this new reality, the rapid deployment of longer, more efficient interconnections between islands, countries and continents has become a priority. Nexans is contributing to the electrification of tomorrow’s world, drawing upon 120 years of know-how and expertise in the manufacture, installation and project management of subsea cables.

Challenges associated with subsea interconnections

Adding renewable energy capacity worldwide is one of the steps to be taken in building an all-electric, low-carbon future. To achieve this, we need to opt for safe, sustainable solutions, particularly for subsea interconnections.

Managing the additional power from renewable sources involves deploying a significant number of new, advanced interconnections, and making them stable and reliable. To connect regions and countries, these cables must be able to carry more energy over longer distances, and in particular to establish subsea links in order to promote the transfer of renewable electricity between communities.

More specifically, high-voltage direct current (HVDC) interconnections play a strategic role in connecting transnational networks by making it possible to:

  • increase connectivity between national power grids and distribute electricity between countries and regions, using, for example, the excess supply in one country to make up for the shortage in another,
  • stabilize the electricity supply,
  • better integrate the various sources of renewable energy,
  • manage the intermittency of renewable energies,
  • strengthen energy security,
  • reduce failure,
  • regulate prices.

Expanding interconnections between countries is a requirement that faces a number of challenges. Installing cables over long distances requires specific expertise, technologies and equipment, particularly cable-laying vessels to ensure the reliability, safety and stability of the network. Few players in the cable industry can meet all these criteria.

At Nexans, our first interconnection project was the Skagerrak subsea link between Denmark and Norway, dating back almost 50 years. Since then, we have undertaken many more projects around the world, enabling us to perfect our knowledge of high-voltage (HV) subsea cable systems and to develop unique know-how. We are involved in a wide range of projects, including creating electricity corridors between countries to strengthen their energy security and independence, while also seeking to make renewable energies more widely available and to balance international supply and demand.


the projected increase
in electricity demand over
the next two decades

13,500 tons

combined capacity of the
3 turntables on Nexans’ new CLV,
which will be able to install up to
4 cables simultaneously


number of interconnection projects
conducted by Nexans, representing
46 GW of installed capacity,
+10,680 km of subsea cables deployed

Nexans solutions

  • Develop reliable interconnections able to carry more energy over longer distances at sea and on land, contributing to the exchange of energy between communities or countries.
  • Deploy turnkey HVDC interconnection solutions to connect transnational networks.
  • Carry out complex cable-laying operations in water of any depth, from the shallowest to the deepest, in order to connect countries or offshore wind farms.

Protecting subsea cables with Nexans IMR

Major electricity transfer lines can experience year-long outages without a contingency plan, leading to economic losses and delays in sourcing experts for repairs. Nexans offers expertise, dedicated personnel, and assets to address such unforeseen challenges.

With Nexans Inspection, Maintenance and Repair (IMR) agreements, cable failure risks are minimized through proactive inspection and maintenance, reducing response times to incidents. Nexans has a proven track record in cable repairs globally, including in Asia, Africa, Europe, and the North Sea region, with over 40 years of experience and successful installations of over 50 offshore repair joints under harsh weather conditions.

High-capacity subsea cables are set to play a growing role in the energy transition. These cost-effective high voltage solutions not only connect offshore wind capacity to onshore consumers, but also provide energy interconnections between nations, making renewables more competitive, as well as enabling markets and strengthening energy security.

, Nexans

Our objectives

Deliver turnkey solutions for interconnection projects, including the engineering, manufacturing, laying, protection and commissioning of HV subsea and land cables.

Meet the requirements of public and private operators with customized support, advice and advanced solutions.

Guarantee a secure power supply by making HV cable systems more reliable through turnkey solutions.

Our latest success stories


Subsea interconnection

Celtic: world longest interconnector cable
Nexans Aurora

Subsea interconnection

Crete–Attica interconnection

Our installation capabilities

C/S Nexans Skagerrak

The current pride of the fleet is the C/S Nexans Skagerrak, with a 7,000 tons capacity turntable, a state-of-the-art dynamic positioning system, touchdown monitoring ROV and Capject trencher. During the years, this cable-laying vessel has installed the longest and deepest cable links around the world, most recently the Monita link between Montenegro and Italy and the NordLink between Norway and Germany. The vessel is also capable of performing both deep water and shallow water repairs of the installed power cable links and can deploy Nexans’ Capjet trenching system for protection. There are multiple examples of the C/S Nexans Skagerrak in repair actions like the repairs of damages to the 400 kV HVAC submarine cables across the Strait of Gibraltar and the 450 kV HVDC cable between Norway and the Netherlands.

CLV Nexans Aurora

CLV Nexans Aurora is part of Nexans’ initiative to reinforce its manufacturing and installation capacities to meet the growing demand for high voltage (HV) cabling systems – particularly those for interconnectors and offshore wind projects worldwide. It has the ability to operate even in the most severe of weather conditions and has a 10 000-tons capacity turntable. The laying equipment allows it to perform complex installation operations of flexible products, including power cables and umbilicals, in shallow and deep water

Cable laying vessel Nexans Aurora

CLV Nexans Electra

Building upon the cutting-edge technology featured on Nexans’ flagship vessel, the Nexans Electra goes further with improved design, comfort and capabilities. Equipped with three turntables, offering a 13,500-tonne loading capacity, and hosting a large range of subsea tooling including jetting and ploughing tools, this vessel will be capable of laying up to four cables simultaneously to meet specific customer requirements, especially on large-scale projects. This vessel will be delivered in 2026.

Cable laying vessel Nexans Electra
Nexans Skagerrak
CLV Nexans Aurora
CLV Nexans Electra

Frequently asked questions about subsea interconnections