Spain-France submarine interconnection

This new submarine electricity interconnection through the Bay of Biscay represents a challenge that will enable the electricity exchange capacity between Spain and France to be increased up to 5,000 MW, compared to the current 2,800 MW.

The submarine electricity interconnection through the Bay of Biscay

The new electricity link through the Bay of Biscay, with a length of almost 400 kilometres, will strengthen the interconnection between Spain and France by improving security and guarantee of supply, increasing the efficiency of both electricity systems and allowing a greater integration of renewable energies. This interconnection, designated as a Project of Common Interest (PCI) in 2013, poses a major challenge for France, Spain and Europe in the achievement of the goals set out regarding energy transition in Europe.

The new interconnection between the Gatika substation (near Bilbao, Spain) and the Cubnezais substation (in the French region of Aquitaine) consists of 4 cables, two per link. This underwater and underground direct current dual link will have a transmission capacity of 2x1,000 MW.

This new interconnection represents a new challenge for Red Eléctrica after having successfully completed and commissioned the Baixas-Santa Llogaia underground interconnection in the eastern Pyrenees.

A European 'Project of Common Interest'

The new electricity interconnection between Spain and France has been designated as a European ‘Project of Common Interest (PCI)’. Spain currently has a level of interconnection with Europe that is far from the minimum set by the European Union (EU) for 2020: a minimum of 10% of installed production capacity. The EU established this minimum in 2002 in order to eliminate isolated electricity systems, facilitate mutual support and promote the European Single Electricity Market.

This new link is essential as it will increase the commercial exchange capacity, bringing the current capacity from 2,800 MW up to 5,000 MW. Nonetheless, Spain will continue to need to develop new interconnections. However, even with the commissioning of the rest of the interconnections planned up to 2020, Spain will continue be the only continental European country below the minimum exchange capacity set by the European Union.

INELFE, company responsible for the project

INELFE is a joint-stock company founded on 1 October 2008 with shares held equally by the companies responsible for the management and operation of the Spanish and French electricity transmission grids, Red Eléctrica de España (REE) and Réseau de Transport d’Eléctricité (RTE) respectively.

INELFE is a simplified joint-stock company governed by French law and which has already carried out the project and commissioned the first electricity interconnection between France and Spain through the Pyrenees.

Access to INELFE website

Technical features

This interconnection is composed of a dual submarine and underground link that will have a length of 370 kilometres, of which 280 kilometres will be submarine cable. The line will be in direct current, instead of alternating current used in both the Spanish and French transmission grids, whereby it will require converter stations at each end of the interconnection line.

On the Spanish side of the project, the link will connect to the Gatika substation (northeast of Bilbao, Spain), 10 km from the Basque coastline.
On the French side of the project, the link will connect to the Cubnezais substation (north of Bordeaux, France). The underground route from the French coast landfall point to the substation will cover a stretch of 80 km.
The links will be mainly underwater, with a length of approximately 300 km, from the Basque coast in Spain to the French Médoc coast, except for a short underground section needed to avoid the submarine Capbreton canyon.