Spain-France Bay of Biscay Power Link Reaches 70% Completion

The electricity interconnector being built across the Bay of Biscay to link Spain and France is now 70% complete, according to a 30 October report from Offshore Energy, with the last stretches of submarine cable now in the water and the project’s converter station in Spain moving into electromechanical assembly. Once operational, the link will raise cross-border exchange capacity between the two countries from 2.8 GW to 5 GW.

Cable Route Now Fully Laid

The interconnector runs from Gatika, in Spain’s Basque Country, to Cubnezais in France, crossing the Bay of Biscay largely underwater before coming ashore. On the Spanish side, roughly 13 km of underground HVDC cable connects the Gatika converter station to the coast at Lemoiz. The offshore section was installed in two phases by two separate contractors: a first 65 km segment, laid by NKT’s cable-laying vessel Victoria and completed in August 2026, and a second roughly 50 km segment laid more recently by Prysmian’s vessel Monna Lisa. With both phases finished, every planned section of submarine cable in the Biscay crossing is now in place.

The project is being developed by Inelfe, the 50:50 joint venture between Spain’s grid operator Red Eléctrica and its French counterpart, RTE, which has handled previous Spain-France interconnection projects.

Two Figures, Two Different Scopes

Readers tracking the project’s cost should note that figures circulating for it describe different things. The roughly €800 million figure attached to Prysmian’s contract covers only the submarine cable engineering, procurement, construction and installation (EPCI) package. Offshore Energy’s report puts the total project cost at about €3.1 billion, a figure that would also cover the converter stations, onshore cable sections and other works beyond the subsea cable alone. The two numbers are not competing estimates of the same thing — they describe different slices of the same project.

Converter Station Work and a 2028 Target

On the Spanish side, civil works at the Gatika converter station are complete, and electromechanical assembly — installing the equipment that converts the direct current carried by the subsea cable back into alternating current for the grid — is now under way. Red Eléctrica’s own public materials on the Inelfe-led project have previously pointed to commercial service starting around 2028, a timeline the October progress report does not contradict, though it does not give its own exact in-service date.

Filling a Gap in Europe’s Grid

The Iberian Peninsula has long been one of the more weakly interconnected corners of the European electricity grid, exchanging power with the rest of the continent mainly through a limited number of links across the Pyrenees. The Biscay project, backed by the EU’s CINEA agency and the European Investment Bank and listed as a Project of Common Interest, is meant to ease that bottleneck. Grid operators elsewhere in Europe are pursuing similar upgrades: National Grid in Britain recently committed £400 million to extend the working life of its IFA interconnector with France to 2050, part of a broader pattern of utilities locking in cross-border transmission capacity for decades to come.

Sources

• Offshore Energy, “€3.1 Billion Spain-France Interconnector Is 70% Complete,” 30 October 2026, offshore-energy.biz (completion percentage, cable-laying phases, contractors, converter station status, total cost figure)
• Red Eléctrica (ree.es), public project materials on the Inelfe Bay of Biscay interconnector (project structure, 2028 commercial-service target)

Illustrative image. Photo: Frans Berkelaar, CC BY 2.0, via Wikimedia Commons — source