The European Union establishes that all member countries should have a commercial interconnection capacity of at least 15% of their installed power by 2030. Currently, the interconnection between Spain and France barely exceeds 3%. Although Spain is still an "energy island" due to its low exchange capacity, it has several operational lines and ambitious projects, including the Electric Interconnection Project across the Bay of Biscay and the two trans-Pyrenean lines included in the current electrical planning, classified as "Projects of Common Interest" by the European Commission.
The Electric Interconnection Project across the Bay of Biscay is a project developed by Inelfe (a 50% joint venture between Redeia –through Red Eléctrica– and its French counterpart RTE) that will increase the commercial exchange capacity between the peninsula and Europe from the current 2,800 mW to 5,000 MW.
The infrastructure –underground and underwater– is already 70% complete. On land, the underground conduits of 13 km connecting the coast of Lemoiz with Gatika are being finalised, which began in 2025 after overcoming years of environmental and social procedures. Meanwhile, the civil works of the Gatika converter station are in full swing, and the construction and equipment installation work will conclude by the end of 2028.
At sea, Red Eléctrica has already completed the first phase of the laying of the submarine cable on the Basque coast, which began in August, with an initial stretch of 65 km
At sea, Red Eléctrica has already completed the first phase of the underwater cable laying on the Basque coast, which began in August, with an initial stretch of 65 km executed by the Danish company NKT. The laying, which will continue until the summer of 2027, will reach depths of up to 140 metres and will have to navigate the complex topography of the Capbreton canyon.
Total Length: Approximately 400 km, of which 276 km are underwater.
Route: Connects the substations of Gatika (near Bilbao, Spain) and Cubnezais (near Bordeaux, France)
Technology: Utilises high voltage direct current (HVDC), necessary to avoid losses over such long distances under the sea (a standard loss would be 15% every thousand kilometres). It consists of two independent links (two circuits), each with a capacity of 1,000 MW. It includes the construction of converter stations at both
ends to transform the energy to alternating current and feed it into the national grid.
The electrical interconnection across the Gulf of Biscay - with a length of 400 km, of which 276 are underwater - will increase the commercial exchange capacity between the Peninsula and Europe from the current 2,800 MW to 5,000 MW
Institutional support: The project has a grant of 578 million euros from the Connecting Europe Facility (CEF) programme, as it is considered a Project of Common Interest (PCI). In June 2025, the European Investment Bank (EIB) approved a loan of 1.6 billion euros to support the construction.
As of today, there are four main connection points across the Pyrenees, with a commercial exchange capacity of around 2,800 MW:
Santa Llogaia (Girona) – Baixas (France) Line: is the most modern connection. Inaugurated in 2015, it is a fully underground direct current line (HVDC) of 64.5 km that crosses the Pyrenees through an 8.5 km tunnel. It doubled the exchange capacity at the time.
Vic – Baixas Line: 400 kV connection (alternating current).
Arkale – Argia Line: Located in the Basque Country, connects Guipúzcoa with the French side.
Hernani – Argia Line: Another key connection in the western Pyrenees area.