The construction works for Celtic Interconnector, the first interconnector between Ireland and France, are well underway, with converter station sites on both sides of the project achieving “significant progress” , Irish transmission system operator (TSO) EirGrid reported.
On the Irish side in Ballyadam, near Carrigtwohill, Cork, Siemens Energy and its subcontractors recently completed the enabling and earthworks phase for the converter station and have mobilized for the main civil works phase at the site.
On the Ar Merzher converter station site in Finistère, France, the main civil works are advancing with the main building steel structure and building cladding ongoing, with French TSO Réseau de Transport d’Electricité (RTE) recently marking one year of construction activity.
Works have also started at the newly named Gogganstown 400 kV substation in Ireland which will be located adjacent to the ESB Knockraha 220 kV substation. This is a single-bay substation, to facilitate connection to the existing Knockraha substation where the 400 kV electrical connection from the interconnector will be transformed down to 220 kV for connection into the transmission network.
According to EirGrid, other progress includes over 90% of the 400 kV AC cable trenching and ducting completed and works are underway on the 320 kV DC cable trenching and ducting. Joint bays are installed with passing bays in place to facilitate traffic flow while cable pulling and jointing take place.
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.