SONI (System Operator for Northern Ireland), welcomes the findings of independent studies into the North South Interconnector commissioned by the Minister for Communications, Climate Action and Environment in the Republic of Ireland.

An International Expert Commission examined the technical feasibility and cost of undergrounding the interconnector; the findings support both SONI and EirGrid’s approach to the project, confirming that an overhead line is the best technical solution and the most cost efficient for consumers.

Robin McCormick, General Manager, SONI, said it was reassuring that the study endorsed the overhead line solution that has received planning approval in both Northern Ireland and Ireland:

“We welcome the publication of the reports commissioned by Minister Naughten, and acknowledge the independence and integrity of the studies.

“We have worked with our colleagues in EirGrid in considering all possible options regarding the delivery of the interconnector, and are encouraged that the panel has concluded that an overhead line is the most beneficial way of meeting the need for enhanced power transfer capability between Northern Ireland and the Republic.”

The North South Interconnector is a c. £250million investment that will connect the electricity grids of Northern Ireland and Ireland. The 400 kV line will run through South Tyrone and Armagh before crossing the border into counties, Cavan, Monaghan and Meath.

The interconnector will underpin the efficient operation of the all-island electricity market, fixing a bottle-neck that cost millions of pounds every year and applying downward pressure on electricity prices.

In 2012, an independent report into the project was published by an International Expert Commission appointed by the Irish Government. Today’s study is an update to the 2012 report and examines possible changes in technology and costs which may have taken place in the intervening years.

The study finds that the cost of both the overhead line and underground cable solutions has increased. However the underground solution is more expensive. According to this latest Irish government report, the cost difference is €450 million.

Mr McCormick added:

“Due to its strategic importance, it is crucial that the North South Interconnector provides a highly reliable link between the two transmission systems on the island.

“The only feasible way to underground such a circuit is to use specialised technology with expensive conversion equipment at each end. Although the study acknowledges there have been developments in this area, in our view it represents unacceptable technical risk and hundreds of millions of pounds of extra costs.

“This is a critical piece of infrastructure for the island, which we are committed to delivering; and while we work through a legal challenge to the planning approval in Northern Ireland, we will continue our engagement with landowners and the community.”

For more information on the North South Interconnector, including Frequently Asked Questions, click here.