Europe Plugs In: Spain–France Link Sets a New Benchmark

€1.6bn subsea project lifts cross-border capacity to 5GW

17 Nov 2025

Europe’s plan to strengthen its power system has moved forward with a €1.6bn subsea electricity link between Spain and France, backed by the European Investment Bank. The project aims to ease grid constraints, stabilise wholesale prices and support a more integrated low-carbon network across the continent.

The 400km connection is being developed by Inelfe, a joint venture between France’s RTE and Spain’s Red Eléctrica de España. When completed, the interconnector is expected to raise the two countries’ exchange capacity from about 2.8GW to 5GW, a significant increase for a region seeking deeper grid integration and improved security of supply.

Running mainly beneath the Bay of Biscay, the link is designed to speed and stabilise power flows between the two systems. Operators expect the project to help both markets draw on each other’s renewable output during periods of stress, reducing the risk of shortfalls and moderating price swings. A senior official at the European Commission said expanding cross-border capacity was essential for building a “resilient and climate-aligned European grid”.

Technical and regulatory hurdles remain. Repairs to underwater cables require specialised vessels and trained crews, and Europe’s limited fleet could delay emergency works. Environmental reviews in the Bay of Biscay may also extend timelines as regulators assess potential effects on marine habitats.

Supporters argue that the long-term benefits outweigh these constraints, citing lower system costs, enhanced reliability and stronger regional energy security. The project is also being viewed as a possible model for future links as offshore wind development accelerates and electricity trading becomes more important to Europe’s decarbonisation plans.

Several member states are already examining similar subsea routes that would connect national networks into a more cohesive European grid. Analysts say the Spain–France line may mark the start of a broader wave of large-scale interconnectors across the region.

Construction is set to progress in the coming years. If performance matches expectations, the project could draw further investment, encourage new technologies and reinforce the foundations of a more flexible European power system.