SupraMarine consortium formed by leading European players

• Air Liquide, CentraleSupélec, ITP Interpipe, Nexans, and RTE have joined forces to develop a superconducting power transmission demonstrator designed to accelerate energy transition
• Called SupraMarine, the project is key to developing a subsea superconducting system, which will ultimately strengthen the competitiveness of offshore wind energy far from the coast
• Each partner brings complementary expertise to this cutting-edge technology

Paris, November 6, 2025 – Air Liquide, CentraleSupélec, ITP Interpipe, Nexans and RTE have formed a consortium to develop a High Voltage Alternating Current (HVAC) superconducting power transmission system demonstrator.

The SupraMarine project will study the electrical connection between offshore wind farms and the coastline using High-Temperature Superconducting (HTS) cables. Superconducting cables, cooled by liquid nitrogen, transport electricity with near-zero energy loss.

Such a system would offer major advantages for the energy transition by improving the competitiveness of offshore wind power installed far from the coast, compared to a direct current connection. It could thus contribute to developing the industrial sector of superconductivity, while helping to reduce Europe's dependence on imports of electronic equipment.

The cutting-edge technology demonstrator would represent a breakthrough in energy transmission from offshore wind farms by adapting and simplifying part of the electrical grid connection. The SupraMarine project would offer an alternative solution to the growing offshore wind energy supply chain challenges, while sourcing most of its materials from Europe.

*High-Temperature Superconductor

The SupraMarine consortium relies on leading European players that bring complementary expertise to the project:

• Air Liquide will supply the cryogenic plants featuring its Turbo-Brayton technology, crucial for maintaining the superconducting state of the cables, and will also conduct in-depth studies on the system’s thermal performance and oversee its cryogenic operations;
• CentraleSupélec, through GeePs laboratory (Université Paris-Saclay, Sorbonne Université, CNRS, CentraleSupélec) will bring its expertise ranging from experimental platforms to doctoral research student training to overcome key scientific barriers;
• ITP Interpipe will design the highly-insulated rigid Pipe-in-Pipe cryostat envelope, a key element that safeguards the superconducting state of the cables and underpins the overall performance of the system;
• Nexans, as the leading innovator in superconducting cables and systems, will ensure the development of the advanced HVAC superconducting cables, junctions and terminations;
• RTE will provide its insights as a leading grid operator, ensuring the research aligns with real-world grid integration requirements.

The testing of the demonstrator is planned by 2028.
The SupraMarine project was awarded a grant of €7.3 million.