The Celtic Interconnector - What is it?

The Republic of Ireland and France united by a thin blue cable with electricity signals over it

The Celtic Interconnector is a proposed electricity and optic fibre cable connection between France and Ireland. The subsea cable of approximately 500km in length and 75km of on-land cable would run between a connection point in the south of Ireland to Brittany in the north-west coast of France.

Brittany is a cultural region and the traditional homeland of the Celtic Breton people and is recognised as one of the six Celtic nations. Hence the name “Celtic Interconnector”.

How did the Celtic Interconnector project start?

Research into the feasibility of the Celtic Interconnector has been ongoing long before Brexit was even on the table. Eirgrid reported on the possibility of the interconnector as early as 2009 in their “Interconnection Economic Feasibility” report.

The report mainly focused on the economic benefits such a connection might bring, and the different scenarios which would have an effect on the project, as well as how energy prices might be affected. The results of the investigation carried out in the report were favourable and further research into detailed costings of such a project was called for.

The case was also put forward for Ireland being able to export wind-powered renewable energy to Europe when its renewable energy infrastructure is further developed. The project is now a joint venture between Eirgrid and RTE (le reseau de transport d'electricite, the French equivalent of Eirgrid).

Eirgrid and RTE are responsible for the operation, maintenance and development of the electricity transmission infrastructure in Ireland and France respectively.

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What are the stages of the Celtic Interconnector project?

The Celtic Interconnector project is progressing at an accelerated pace, as most projects marked of common interest do. The initial planning allowed for the following phases:

  • 2014-2016: Feasibility studies
  • 2017-2018: Initial design and pre-consultation
  • 2019-2021: Detailed design and consults
  • 2022-2026: Construction

As such, Eirgrid and RTE are currently immersed in the design and consultation phase, with construction set to begin in 2022.

How much will the Celtic Interconnector cost to build?

As of 25 April 2019, financing has been secured for the project and it looks certain to go ahead. With a cost of nearly €930 million euros, the Celtic Interconnector will be mainly funded by the EU, who are likely to shell out for around 60% of the bill, with France offering to pay 35%.


What are the possible advantages of the Celtic Interconnector?

Although a massive undertaking requiring extensive funding, the Celtic Interconnector could provide sizeable benefits such as:

  • Provide a more secure energy supply, as France would be Ireland’s only EU sourced of electricity after the UK exits the European Union.
  • Being able to import and export more electricity - up to 700MW, enough to power around 450,000 homes.
  • Drive down electricity prices in Ireland for consumers.

Also of interest is the fact that fibre optic cable will be laid along with electric cables, physically connecting Ireland to Europe’s internet resources. One of the most important points in our opinion is the possibility of lowering energy prices in Ireland, by increasing competition and enabling easier access to our electricity market.

Unfortunately, Irish energy prices are among the highest in Europe, due to several factors, our location being an important one. The Celtic Interconnector could, hopefully, remove location as a consideration for our energy pricing by enabling the Irish government to purchase cheaper electricity in France.

In the table below, you can see the cheapest electricity offer per Irish supplier.

Cheapest Electricity Offer per Supplier
Supplier Best offer Price per year
Bright Energy Standard €1,473.00
Bord Gáis Energy 40% Discount €962.00
Community Power Standard €2,019.08
Ecopower 25% Discount €1,314.57
Electric Ireland 5.5% Discount
€150 Cashback
Energia 41% Discount
€140 Cashback
Flogas 15% Discount €1,743.42


Iberdrola 26% Discount
€200 Cashback
Panda Power 10%
€250 Cashback
Pinergy Standard €2,028.73
Prepay Power Standard €1,516.97
SSE Airtricity 33% Discount €1,037.88
Waterpower Standard €1,985.27
Find the Best Offer for Your Home.
Call  01 903 6528 
Find the Best Offer for Your Home.
Call  01 903 6528 

*Figures are for illustrative purposes only. Calculations based on average consumption figures for an urban home with a 24-hour standard meter. All discounts and cashback have been applied. Last updated: January 2022

Brexit-proof Irish electricity

The impending construction of the Interconnector could also soothe nerves for citizens that have been alarmed over how Brexit will affect Irish energy, due to the gas and electricity connections between the UK and the ROI.

The EU’s stake in this is also somewhat strategic: By rescuing Ireland from geographical isolation following Brexit, the EU will be strengthening its ties with Europe as well as gaining access to the potential for renewable energy generation in Ireland. The French grid is already interconnected with Belgium, Great Britain, Italy, Spain and Switzerland.

Access to the massive European power market through France would mean Ireland would no longer be dependent on its UK electricity connections. It remains to be seen what will be done about our gas supply (which is managed by Gas Networks Ireland), although gas use should be phased out or replaced in keeping with our international commitments to lowering our carbon footprint and greenhouse gas emissions.

Will France see any benefit?

The Celtic Interconnector project has been earmarked a project of common interest by the EU, improving the movement and distribution of energy around Europe. Better interconnection means that surplus generated energy can be diverted from one country to another where there is a lack.

In fact, one of the motivations behind its construction is so that France can tap into the green energy potential that Ireland could generate, mainly its capacity for wind-powered renewable energy. Given Ireland’s abysmal progress towards its Paris agreement targets, this will hopefully translate to a renewed impetus, and more pressure on the responsible parties, to increase our wind power capabilities.

What are the possible disadvantages of the Celtic Interconnector?

As the construction of the interconnector will require on-land and sea operations, environmental impact studies must be carried out and great care should be taken to minimize any possible negative impact on the local environments.

A public consultation was launched in France to discuss any concerns raised regarding laying the high-voltage cables. Some thorny issues have arisen over the environmental impact, and will hopefully be addressed and resolved during this consultation phase before construction starts in 2022.

An eight-week consultation was run by Eirgrid in Ireland and finished on 10 June 2019. Eirgrid is currently still processing the feedback received during the consultation before deciding on the landfall sites and converter station locations, as well as preparing to respond to the questions they received. You can check the most up-to-date information on Eirgrid’s Celtic Interconnector “What’s happening now?” page.

The shortlisted locations for the landfall (where the cable will surface) locations are:

  1. Ballinwilling strand
  2. Claycastle Beach
  3. Redbarn Beach

The six shortlisted locations for the necessary converter station (to reduce the voltage and enable the electricity to be shared on the Irish grid) are:

  1. Ballyadam
  2. Ballyvatta
  3. Kilquane
  4. Knockraha
  5. Leamlara
  6. Pigeon Hill

This was not the first round of consultation, another round which finished in 2018 confirmed East Cork as the best location for the Interconnector.

How do I contact Eirgrid regarding the Celtic Interconnector?

If you have questions to ask, views to be shared, or simply wish to request information on the Celtic Interconnector, Eirgrid has made the following methods of contact available to the general Irish public.

You can also read through the many documents, studies and analyses provided by Eirgrid. The CRU, Ireland’s energy watchdog, have also published various information papers and responses regarding the Celtic Interconnector.

For queries in writing...

The Celtic Interconnector Project Manager,
EirGrid plc.,
The Oval,
160 Shelbourne Road,
Dublin 4.

For queries via email...

For queries via telephone...

Michelle Walsh (CI Liaison Officer): +353 (0)85 870 4999
Eoghan O'Sullivan (Community Liaison Officer): +353 (0)87 247 7732
Eirgrid Customer Relations: +353 (0)1 237 0472

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