Cable company joins project to demonstrate superconducting cables for offshore transmission

The SupraMarine project will study the electrical connection between offshore windfarms and the shore using high-temperature superconducting (HTS) cables. Superconducting cables, cooled by liquid nitrogen, would transmit electricity with near-zero energy losses. For the offshore wind industry, using superconducting cables would have a number of advantages in addition to reduced energy losses, and is also expected to provide capex and opex savings.

The partners in the project said the technology could provide major advantages for the energy transition, improving the competitiveness of offshore wind installed far from shore, compared with a direct current connection. If successful, the technology demonstrator could provide a breakthrough in energy transmission from offshore windfarms, adapting and simplifying grid connections. 

Air Liquide will supply the cryogenic equipment, featuring its ‘Turbo-Brayton’ technology, to maintain the superconducting state of cables. It will also conduct indepth studies on the system’s thermal performance and oversee its cryogenic operations.

CentraleSupélec, through the GeePs laboratory at Université Paris-Saclay, Sorbonne Université, will provide expertise ranging from experimental platforms to doctoral research student training to overcome key scientific barriers.

ITP Interpipe will design a highly-insulated rigid pipe-in-pipe cryostat envelope, which will safeguard the superconducting state of cables, underpinning the overall performance of the system.

Nexans will be responsible for the development of the HVAC superconducting cables, junctions and terminations, and RTE will provide insights as a grid operator, ensuring the research aligns with real-world grid integration requirements.

Testing is due to commence by 2028. The SupraMarine project was awarded a grant of €7.3M (US$8.4M) from the French State from ADEME, the French Agency for the Ecological Transition.