Greenlink is planned to be a 500MW subsea and underground cable interconnector (with associated converter stations) between the existing electricity grids in Ireland and the UK. The project will provide a new grid connection between Great Island transmission substation in Wexford and Pembroke transmission substation in south Wales.
Greenlink will stretch approximately 200km and will employ high voltage direct current (HVDC) to link the two power systems, a proven technology that has several advantages over an alternating current (AC) connection: technically easier over this distance, lower unit costs, much more easy to control according to trading and market requirements, and much lower losses.
Greenlink will have key strategic importance as it will provide significant additional interconnection between Ireland, the UK and continental Europe. The construction and development of Greenlink will deliver increased energy security, inward investment and value for money for consumers, enabling the further integration of low carbon renewable energy sources.
Greenlink will consist of two converter stations, each located close to the identified existing substations: Great Island Substation in County Wexford (Ireland) and Pembroke Substation in Pembrokeshire (Wales). The converter stations will be connected to each other by two electricity cables and a fibre optic cable that will enable the two converter stations to communicate for control purposes. The interconnector itself is unobtrusive, being mainly a subsea cable with a converter station located at each connection point.
The project will require planning permission in Ireland and Wales. Constructing and commissioning an interconnector requires the completion of a thorough programme of environmental and technical assessment to ensure that the final interconnector design fully considers the environment in which it is built. The Greenlink interconnector is planned for commissioning in 2023.