North South 400 kV Interconnection Development

This project proposes the addition of a new 400 kV overhead line to our grid, connecting the electricity grids of Ireland and Northern Ireland. This proposed line would run through counties Monaghan, Cavan and Meath in Ireland, and Armagh and Tyrone in Northern Ireland.

This project proposes the addition of a new 400 kV overhead line to our grid, connecting the electricity grids of Ireland and Northern Ireland. This proposed line would run through counties Monaghan, Cavan and Meath in Ireland, and Armagh and Tyrone in Northern Ireland.

As with all our major projects, we have undertaken an extensive process of public consultation on this proposal.

Planning permission in Ireland

In December 2016, An Bord Pleanála granted planning approval for the section of this line in Ireland. This was subsequently made the subject of judicial review proceedings in the High Court. The proceedings were dismissed by the High Court in August 2017. An appeal was then dismissed by the Supreme Court in February 2019. The project has now cleared all the planning and legal hurdles in Ireland.

Planning permission in Northern Ireland

In Northern Ireland, the Department for Infrastructure approved planning permission in January 2018. However, in February 2019, DFI conceded to a legal challenge against the planning permission. This challenge argued that planning approval could not be granted in the absence of an Infrastructure Minister.

In September 2020, following the re-establishment of the Stormont Executive, SONI welcomed the decision by Minister Mallon MLA to approve planning permission for the North South Interconnector in Northern Ireland.

This planning approval is now subject to judicial review. We are hopeful that the judicial review process will be progressed efficiently and that an outcome will be reached without delay to allow construction to commence. However, as a result of the extensive planning process and subsequent legal challenge, EirGrid and SONI are now anticipating that the North South Interconnector will be completed in 2025.

Project of Common Interest

In October 2013, the European Commission designated this cross-border interconnector as a Project of Common Interest (PCI) under EU Regulation No. 347/2013. This streamlines the permit granting process for designated projects, while also requiring meaningful public participation. An Bord Pleanála has been designated the competent authority to manage the PCI process in the Republic of Ireland. Within An Bord Pleanála its PCI unit is distinct from its strategic infrastructure development (SID) unit.

Click here to find out more about PCI status and the European Commission.

A project summary is available to download in report format via the following link: Project Summary Report.

Details of the Northern Ireland element of the project can be found here.

Answering Your Questions-Web Film Series

We have produced six new web films in response to key issues that have arisen during public consultation.

The purpose of the films is to address each of those issues under six different headings: why the Interconnector is needed, the underground option, tourism, public consultation, land usage and health. This allows you to find clear answers to questions and concerns that have been raised.

The interviews were conducted on farmland in North Leinster where power lines are already in place, to give each message a relevant context. In addition, graphics were added to clarify some of the technical points that were discussed in the interviews.

For a more in depth explanation of the six key concerns we identified read our corresponding brochure here.

Why is this project needed?

EirGrid Group operates the power grid across the entire island - but currently there is only one interconnector between the two jurisdictions and should a problem occur with this it could result in widespread power failures across one or both jurisdictions.  To prevent this from happening, or at the very least limit the impact of its occurrence, we have to restrict the amount of power that can flow through the interconnector to levels that are well below what customers require. The only way to resolve this urgent problem is to install a second interconnector, similar in size to the existing interconnector. This will eliminate the risk of a single event resulting in widespread power failures thus allowing us to remove the restrictions on cross-border flows of electricity. This will in turn allow us to operate a more efficient and cost effective electricity grid.

We are therefore proposing to add a second, higher-capacity interconnector. It would connect to the network in Northern Ireland in County Tyrone, cross the border between Armagh and Monaghan and then join the network in Ireland at an existing substation in County Meath.

As this is a cross-border project, it is subject to planning laws in both jurisdictions. The grid in Northern Ireland is managed by SONI – the System Operator for Northern Ireland. For details on the Northern Ireland section of the interconnector, please visit the SONI project website.

What are the benefits of this project?

The introduction of the second North South interconnector will improve the security of electricity supply across the island of Ireland. It will help to improve the efficiency of the electricity system, reducing costs and ultimately saving money for the end user, the electricity customer.

Increased capacity in the connection between our networks will also help in facilitating the connection of more renewable electricity generation to the grid. This is essential to achieve renewable energy targets set by the EU, and to increase our energy independence. by reducing our reliance on imported fossil fuels such as oil and natural gas.

It will also provide a local benefit for the people of the north east by increasing the capacity of the electricity network in the region which will help to attract inward investment and jobs.