North South Interconnector

This project proposes the addition of a new 400 kV overhead line to our grid, connecting the electricity grids of Northern Ireland and the Republic of Ireland. It is also known in Northern Ireland as the Tyrone to Cavan Interconnector. When built, the project will start at a substation in Turleenan, Co Tyrone. It will then run into Co Armagh and then into counties Monaghan, Cavan and Meath.

The Project

The Tyrone to Cavan Interconnector (also known as the North South Interconnector) will start at a substation in Turleenan, Co Tyrone. It will then run into Co Armagh and then into counties Monaghan, Cavan and Meath. It will connect the electricity grids in Northern Ireland and the Republic of Ireland.

SONI is responsible for securing planning consent for the project and leading on stakeholder engagement, until we hand over to NIE Networks for the construction phase.  

This is a significant project for SONI and for everyone in Northern Ireland. It will remove a costly bottleneck on the grid, saving consumers in Northern Ireland £20m/year and will improve the reliability and security of your electricity supply. 

In September 2020, following the re-establishment of the Northern Ireland Executive, the Infrastructure Minister Nichola Mallon MLA, approved planning permission for the North South Interconnector.

Following a legal challenge to that approval, planning permission was upheld by the High Court in Belfast in October 2021. The window to appeal this decision has now expired and SONI is now pleased to have certainty, as we move forward to deliver this vital project. Once complete the project will be a catalyst for Northern Ireland’s response to climate change, reduce consumer costs and provide a secure long-term electricity supply for Northern Ireland

SONI is working closely with NIE Networks who are responsible for building and maintaining the North South Interconnector and the project is currently on track to be be fully operational by 2026.

The southern element of the project has planning permission following a decision by An Bord Pleanála in December 2016. The project has now cleared all legal and planning hurdles in the Republic of Ireland. Read more here

This project retains its awarded Project of Common Interest (PCI) status by the European Commission. Click here to find out more about PCI status and the European Commission. 

Why is this project needed?

The electricity transmission network operates on an all-island basis. However, there is currently only one interconnector linking both jurisdictions. This restricts the amount of electricity that can flow from north to south and vice versa, creating a bottleneck that adds costs to consumer bills.

The second North South Interconnector will remove this constraint and allow the all-island network to operate much more efficiently. This will have a positive impact on electricity prices and will create significant savings for consumers everywhere.

The proposed North South Interconnector is also required to make sure we have access to enough electricity to meet supply in Northern Ireland in the coming years. As things stand, the Single Electricity Market’s capacity auctions provide short to medium term security of supply. The North South Interconnector remains critical for electricity security in the long term.

What are the benefits of this project?

Enabling a green recovery

The North South Interconnector is essential to unlocking a green economic recovery as we emerge from the Covid-19 pandemic.

It is a multi-million pound investment which would create significant local construction jobs in its completion.

Once completed, it will be the backbone of the transmission system facilitating the growth of renewables and significant new jobs within the emerging green collar sector, ensuring that the energy transition is just, fair and equitable.

The North South Interconnector is essential for ensuring local businesses have the power they need to expand and to attract foreign direct investment, with investors seeking an efficient, green and secure electricity supply.

By removing the significant bottleneck  the island’s electricity system, Northern Ireland will be able to freely import and export electricity. With the North South Interconnector in place, we will reduce our reliance on volatile imported fossil fuels and can maximise the use of our abundant, clean natural resources, such as wind and solar energy. Again, delivering growth in the green collar sector.

Helping Northern Ireland to combat the climate crisis

It will be a game changer in the island’s response to the climate crisis as it will facilitate the connection of 900MW of renewable generation; enough to power 600,000 homes through green energy.

It is critical to Northern Ireland delivering its contribution to the UK commitment to Net Zero Carbon by 2050. By removing the significant  constraint on the island’s electricity system, Northern Ireland will be able to meet the expected increase in electricity demand, resulting from the uptake of electric vehicles and heat from electricity.

In addition, the North South Interconnector will support Northern Ireland’s new climate change legislation; Energy Strategy and a new target of at least 80% of electricity being generated by renewable sources by 2030.

Delivering sustainable savings for consumers

Recent analysis by the European Network of Transmission System Operators for Electricity (ENTSOE), has suggested that the project will save NI consumers an estimated £20million per year by 2030.

This is because the North South Interconnector removes constraints, which currently add cost to the Northern Ireland consumer.

The electricity system operates on an all-island basis, with an all-island wholesale electricity market.

A more connected grid will mean a more efficient wholesale market resulting in downward pressure on prices – good news for consumers and businesses in both jurisdictions.

Achieving long-term security of supply

The North South Interconnector is essential for a secure, efficient and, increasingly, clean electricity supply for Northern Ireland.

It will improve security of supply North and South of the border by allowing the dispatch of power as and when required to either jurisdiction.

Short-to-medium term security issues have been addressed by capacity auctions as part of the upgraded wholesale electricity market. We now need to address long-term security of supply. By its nature, the surplus or supply-gap of generation in a country or region changes over time due to reasons such as population growth, technological changes, increased demand, new government policy and economic fluctuations.

The North South Interconnector is a long-term project and will help Northern Ireland react to changes in supply and demand in the future.

The North South Interconnector is therefore a safeguard against any changes to surplus or supply gaps, ensuring a more efficient and secure electricity supply on a sustainable basis.


Answering Your Questions

In our consultation about this project, we have heard your concerns. Our goal is to address genuine issues from members of the public, particularly in the project area. We’ve put together a helpful guide to answer your questions and explain basic facts about the project. This can be downloaded here.

We’ve also produced web films in response to key issues that have risen during our consultations with you. We hope this information allows you to find clear answers to questions that have been raised.