Preparatory ops for offshore installation of French-Irish interconnector about to begin

Greece’s Asso.subsea is set to begin boulder clearance and trenching next month for the interconnector that will link the power systems of Ireland and France together for the first time via subsea power cable.

It was reported in May that Asso.subsea had joined forces with French cable maker Nexans to perform subsea burial operations for the Celtic Interconnector.

The Greek company will perform boulder clearance with the use of a grapple, and trenching of the seabed with the use of a plough starting from July, until November. Trenching support vessel Aethra is engaged on the project.

Subsequent campaigns are planned for 2025 and 2026, focusing on post-trenching operations.

The Celtic Interconnector is being developed by the Irish transmission system operator (TSO) EirGrid and its French counterpart Réseau de Transport d’Electricité (RTE).

Nexans, which won the contract for the project in 2022, kicked off the installation of high-voltage alternating current (HVAC) onshore cable on the Irish side of the interconnector in May. Offshore cable installation work is slated to begin next year.

Siemens Energy is delivering the HVDC transmission technology.

When complete in 2026, the 700 MW 320 kV VSC HVDC link will allow the movement of enough electricity to power 450,000 homes.