Construction of a £280M north to south interconnector between Northern Ireland and Ireland is expected to start this autumn if a public inquiry gives its backing.
Construction will be carried out by ESB Networks and planning approval for the southern element infrastructure has already been granted by Ireland’s An Bord Pleanála.
The project, by EirGrid and SONI (System Operator for Northern Ireland), is a new 140km, 400kV cross-boarder overhead line connecting the grids of Ireland and Northern Ireland.
An underground option was considered, however it was dismissed mainly on the grounds of technical risk and cost. For it to go underground a 22m corridor to accommodate two cable trenches would have to be constructed and the line would have to be converted to direct current technology, which would then need the construction of substations at either end.
EirGrid chief executive Fintan Slye has said the interconnector is “undoubtedly the most important infrastructure scheme on the island today.” Construction is expected to be around three years from planning consent.
Currently the electricity transmission network is restricted in the north east of Ireland, particularly where transmission lines cross the border and more capacity is needed.