Greenlink is a proposed subsea and underground electricity interconnector cable (with associated converter stations) linking the existing electricity grids in Ireland and Great Britain (GB), and has a nominal capacity of 500MW. Greenlink will provide a new grid connection between EirGrid’s Great Island substation in County Wexford (Ireland) and National Grid’s Pembroke substation in Pembrokeshire (Wales). The power will be able to flow in either direction, depending on supply and demand in each country.
Greenlink has key strategic importance, as it will provide significant additional interconnection between Ireland and Great Britain, with onward connections to continental Europe. The construction and development of Greenlink will deliver increased energy security, regional investment and value for money to consumers, and will enable the further integration of low carbon renewable energy sources.
The Greenlink proposal alongside other existing and proposed interconnectors in Ireland, UK and continental Europe.
Greenlink will consist of two converter stations - one located close to the Great Island substation in County Wexford and the other close to the Pembroke substation in Pembrokeshire - connected by two High Voltage Direct Current (HVDC) cables under the Irish Sea. A converter station converts electricity from Alternating Current (AC) to Direct Current (DC) and vice versa.
DC electricity is typically used for the transmission of electricity over long distances because it has lower losses, negligible heating effects and is therefore suitable to be buried underground. Accordingly, there will be no overhead lines between the two converter stations. Onshore, the cables will be buried underground and offshore the cables will be buried in the seabed or laid on the seabed with protection, if burial is not practicable.
Greenlink is planned for commissioning in 2024
The project has required planning permission in Ireland and Wales. Constructing and commissioning an interconnector requires the completion of a thorough programme of environmental and technical assessments to ensure that the final project design fully considers the environment in which it is built. Greenlink Interconnector Limited undertook a voluntary Environmental Impact Assessment (EIA), meaning the application documents faced an increased level of scrutiny from stakeholders.
Technical and environmental constraints were identified and fully assessed to ensure that they were considered within the final design of the project. Detailed surveys commenced in 2018, following the completion of desk-based assessments and consultation with statutory consultees.
Once a detailed proposal and design were completed, applications for permits and licences were made to Pembrokeshire County Council, Pembrokeshire Coast National Park Authority, Natural Resources Wales and Milford Haven Port Authority in Wales; and to An Bord Pleanála, the Department of Housing, Planning and Local Government – Foreshore Unit and the Commission for the Regulation of Utilities, in Ireland.
Core consents were obtained in 2021 and preparations are under way for the start of construction in early 2022. Construction is expected to take approximately two and a half years.