Analysis: The Celtic Interconnector will be a key physical manifestation of the importance of Ireland's post-Brexit ties with continental Europe

By Evan Boyle, Alexandra Revez and Brian Ó Gallachóir, ERI/UCC

In recent years, the strengthening of Franco-Irish relations in a post-Brexit context has been evident through political, diplomatic and trade developments. One key manifestation of these improved relations, both physically and symbolically, is the Celtic Interconnector, Ireland’s first direct electricity interconnection with continental Europe.

This 500km underwater electricity cable between Cork and Brittany began construction in November 2023 and electricity flows are expected to begin in 2026. The 700 megawatt cable will move electricity bidirectionally across the Celtic Sea, providing a key contribution to Ireland’s security of electricity supply through a direct link to continental Europe.

In Ireland, security of energy supply is a concern based on our geographical context as an island country on the periphery of Europe. Ireland has historically low levels of interconnection, recently further challenged due to growing uncertainty concerning electricity policy with our closest UK neighbours in the context of Brexit.

But Ireland is also a fascinating and valuable case study in electricity supply security given the current fast pace of penetration of variable wind energy relative to other European regions. This current growth in renewable energy penetration coupled with future plans to substantially grow capacity by harnessing Ireland’s offshore wind energy resources is reshaping the energy system. This brings new challenges in terms of connecting new wind farms into our electricity network and an overall need to modernise the electricity transmission grid.

Beyond the national context, the Celtic Interconnector project is identifying local priorities around sustainability, managing uncertainty and leveraging the potential of the interconnector for cultural exchange between the regional communities in Brittany and Cork. Ireland’s electricity grid operator EirGrid and its French counterpart Réseau de Transport d'Electricité (RTE) are planning cross-border exchange among the communities in Cork and Brittany. In addition, EirGrid has also launched the first phase of the Celtic Interconnector Community Benefit Fund with an initial €960,000 available for eligible community and voluntary groups to apply for.

Community groups, not-for-profit organisations and social enterprises in the project area in Ireland are encouraged to apply to this open call. Community benefit schemes are typically defined as voluntary agreements between local communities and project developers whereby a fixed amount is paid by developers to communities. It is a relatively innovative mechanism to devolve some of the benefits of large energy infrastructure to host communities. Learning from these new mechanisms is an important step toward promoting a just energy transition.

Moving past the regional and national aspects, there are also European considerations in relation to interconnectors. Despite EU financial and regulatory support (many interconnector projects benefit from the EU's Projects of Common Interest designation), the expansion of cross-border interconnectors across Europe has been slow. Notorious delays include the interconnection between the Iberian Peninsula and the rest of Europe and the expansion of a pan-European interconnection between Norway, Germany, and the UK.

Reasons for the stalled progress on many European interconnector projects includes public acceptance issues, lack of awareness and political uncertainty. This is unsurprising as interconnectors bring added complexities and place new land-use demands. Yet, grid expansion involving large-scale reinforcement and interconnection is expected to accelerate substantially because the transition to renewables is increasingly seen as both necessary and inevitable.

The drive towards greater European electricity interconnection requires a strong Europe

Unlike traditional forms of energy supply such as oil, coal or gas, which can be transported to power stations by trucks, ships or trains, renewable energy captures the energy where it is readily available, converts it to electricity, and then transports the electricity through the electrical networks. Thus, efforts to decarbonise the energy system are tied to developing new long-distance electric transmission lines to connect new utility-scale renewable sources to the places where the electricity is used.

A greater level of connectivity between member states in Europe will allow for energy transport efficiencies and the use of renewables commonly far from load centres. Managing increased amounts of variable and intermittent energy, such as wind through interconnector transmission, also offers new opportunities to balance demand and is expected to decrease the need for backup capacity and power curtailment.

As part of the STEPS project, researchers within the MaREI Centre at UCC have been investigating how pre-existing 'Celtic interconnections' are providing foundations for the Celtic Interconnector. Here, we focus on using insights from the social sciences and humanities to draw out the broader relationships which frame this new technological collaboration. For example, the cultural interconnections through language and music (including the annual Lorient Interceltic music festival), and the historical interconnections through migration and trade.

The drive towards greater European electricity interconnection requires a strong Europe. However, 24 EU countries elected at least one member of a Eurosceptic group in the recent European Parliament elections. As such, how we pursue these developments requires deep consideration as to the national and regional relationships upon which such infrastructures are built as well as the technical and financial issues.

Dr Evan Boyle is a postdoctoral researcher with the Department of Sociology and Criminology at UCC and with the MaREI SFI Research Centre for Energy, Climate and Marine (MaREI)/ERI. Dr Alexandra Revez is a Research Fellow in the MaREI Centre and is located in the Environmental Research Institute (ERI) in UCC. She is a former Irish Research Council awardee. Prof Brian Ó Gallachóir is Director of the MaREI Centre/ERI and Associate Vice-President of Sustainability at UCC.