The Greenlink interconnector is now operational, enabling electricity transfer between the UK and Ireland following its integration into the National Grid and EirGrid transmission systems.
The 504MW, 320kV high voltage direct current (HVDC) link spans approximately 200km—160km of which is subsea—connecting substations in Pembroke, Wales and Great Island, County Wexford. It consists of two HVDC subsea cables and converter stations located near each substation.
The interconnector is designed to facilitate the exchange of electricity between the two countries, potentially supporting system resilience and optimizing the use of renewable energy by allowing surplus power to be shared across borders.
On the UK side, National Grid implemented a series of upgrades to its 400kV Pembroke substation to enable the connection. This included the installation of a hybrid gas-insulated switchgear bay within the existing air-insulated infrastructure. The equipment includes insulating and switching technology that minimizes the use of sulphur hexafluoride (SF₆), aligning with broader efforts to reduce greenhouse gas emissions from the electricity network.
In Ireland, the interconnector connects into EirGrid’s Great Island substation. At each end, converter stations transform electricity between direct current (DC) and alternating current (AC), depending on the direction of energy flow.
Greenlink Interconnector Limited is the owner of the project, with EirGrid responsible for operational management.
James O'Reilly, CEO of Greenlink Interconnector Limited, said, "By enabling the transfer of green energy across borders, Greenlink strengthens energy security, enhances sustainability, and fosters greater connectivity with the wider European market.”
John Twomey, director of customer connections at National Grid, said, “As demands on our electricity grids evolve, interconnectors provide immense value by strengthening security of electricity supplies and improving our collective ability to exploit the renewable power produced across borders. Connecting Greenlink to our network ensures we can contribute to, and benefit from, that boost in capacity and resilience as we continue to upgrade our wider network to support Britain’s ambitious clean energy targets.”
