Bay of Biscay

Inelfe’s Bay of Biscay works schedule specifies a "Geotechnical campaign for the land section" in Spain running from late 2024 to Q1 2025. A CINEA/Red Eléctrica April 8, 2025 press release notes that, after several months dedicated to preparatory work for the land section and earthmoving at Gatika, civil works are underway, indicating that the land geotechnical campaign had been completed by the end of Q1 2025. This confirms completion of the geotechnical surveys for the land section in Q1 2025.

On 19 March 2025, Red Eléctrica, via Inelfe’s Bay of Biscay press area, reported that it was progressing with the dismantling of two 10 km overhead power lines between Gatika and Lemoiz in Biscay. This removal of existing lines is part of the Bay of Biscay interconnection works and is intended to reduce visual impact as the new underground HVDC link and converter station infrastructure are built along this corridor.

Inelfe’s official Bay of Biscay works schedule lists a "Geotechnical campaign for the land section" in Spain running from late 2024 to Q1 2025. By April 2025, a CINEA/Red Eléctrica press release reports that, after several months of preparatory work for the land section and earthmoving for the new Gatika converter station, construction is advancing, implying that the land geotechnical investigations had already started in late 2024. Using this, the geotechnical survey start is confirmed in late 2024 (approximate date used).

During the summer of 2024, marine surveys were carried out along the entire offshore route of the Bay of Biscay interconnection in French waters, providing updated seabed and route information ahead of subsea cable installation.

On 15 June 2023, Inelfe awarded Hitachi Energy, in consortium with VINCI Energies and VINCI Construction, a contract to supply four HVDC converter stations for the Biscay Gulf subsea interconnection between France and Spain. The two parallel 1,000 MW, ±400 kV HVDC links—each with a converter station at Gatika in Spain and Cubnezais in France—will provide a combined 2,000 MW of capacity, improving cross‑border security of supply and facilitating integration of emission‑free electricity, with delivery of the stations expected in 2028.

On 5 May 2023, Inelfe awarded Prysmian Group an EPCI contract worth more than €800 million for Cable Link 2 of the Biscay Gulf (Bay of Biscay) interconnection between France and Spain. Under this contract, Prysmian will design, manufacture, install, test and commission approximately 400 km of 400 kV HVDC submarine and land cables, including four landfall sites, to connect the Cubnezais substation in France with the Gatika substation in Spain, delivering 1 GW of capacity as part of the overall 2 GW link scheduled for commissioning in 2028.

On 17 April 2023, Inelfe, the joint venture of Red Eléctrica and RTE, announced the preferred bidders for the Engineering, Procurement and Construction (EPC) contracts for the Biscay Gulf/Bay of Biscay electricity interconnection between Gatika in Spain and Cubnezais in France, covering two 1,000 MW HVDC links, the two converter stations, and associated civil works. This marked a key step towards contracting the converter station suppliers and other EPC scope ahead of construction starting later in 2023.

Prysmian Group was selected by INELFE, the 50:50 joint venture between Spanish grid operator Red Eléctrica and French grid operator Réseau de Transport d’Électricité (RTE), as one of the preferred bidders for the Biscay Gulf (Bay of Biscay) electricity interconnection, covering the supply of almost 800 km of HVDC submarine and land cables for two 1000 MW links between Gatika in Spain and Cubnezais in France. Prysmian entered exclusive contract negotiations with the aim of signing the EPC contract by May 2023.

By 10 March 2023, INELFE (the Red Eléctrica / RTE joint venture) had obtained all the administrative authorisations required to proceed with the Bay of Biscay electricity interconnection between Gatika (Spain) and Cubnezais (France) and awarded the main Engineering, Procurement and Construction (EPC) contracts to Prysmian Group (cables) and Hitachi Energy (converter stations). This milestone followed the 2021-2023 'Authorisations' phase reported on INELFE's official project page: French Ministry of Energy Transition validation of the Route of Least Impact in September 2021, Spanish REE authorisation applications in May 2021, and French RTE applications on 1 December 2021, followed by public inquiries and favourable opinions from independent commissions on both sides. Without all authorisations in place the EPC contract awards would not have been possible. Physical work subsequently began in France in October 2023 and in Spain shortly after. This composite date marks the effective end of the permitting phase for the project.

On 10 March 2023, INELFE — the joint venture equally owned by Spain's Red Eléctrica and France's RTE — awarded the main EPC contracts for the Bay of Biscay electricity interconnection, marking the effective Final Investment Decision for the €3.1 billion project. The contracts were awarded to Prysmian Group (submarine and underground cable scope, ~€800 million) and Hitachi Energy (converter stations at Gatika and Cubnezais). The INELFE structure has no traditional FID event — the binding contract commitment and the Regulators' updated cross-border allocation decision (CRE, 2 March 2023) together represent the moment capital was committed. RTE's 2023 management report cites this date as marking the start of work on the Bay of Biscay interconnector. The final investment is funded by the two transmission system operators (~€2.39bn shared 50/50, plus additional tranches) plus a €578 million CEF grant from the EU and (later) €1.2 billion in EIB loans.

The Biscay Gulf (Bay of Biscay) interconnection was reaffirmed in ENTSO-E’s 2022 Continental South West Regional Investment Plan, linked to the TYNDP 2022 cycle, as a 2,000 MW, 370 km HVDC submarine link between Gatica and Cubnezais that will increase exchange capacity between the Iberian Peninsula and the rest of Europe to 5,000 MW. The document highlights the project’s importance and the joint studies carried out by Red Eléctrica and RTE since 2017.

In September 2021, France’s Ministry of the Energy Transition validated the ‘Route of Least Impact’ for the Biscay Gulf electricity interconnection, following around five years of consultation and route optimisation work by RTE and REE. This route validation for the French section enabled RTE to obtain all the necessary authorisations to start work and effectively concluded the detailed routing and corridor selection for the project in France.

The Environmental Impact Assessment (Estudio de Impacto Ambiental) for the Spanish onshore and submarine sections (Gatika–French border) of the Bay of Biscay interconnection was formally submitted and put to public information by the Spanish authorities. The BOE announcement of 31 May 2021 explicitly states that the project and its EIA are submitted to information pública under Spain’s evaluation procedure for the Interconexión eléctrica España–Francia por el Golfo de Bizkaia.

The Biscay Gulf (Bay of Biscay) HVDC interconnection project was included in ENTSO-E’s 2020 Ten-Year Network Development Plan (TYNDP), described as a new 2,000 MW, 370 km submarine link between the Gatica and Cubnezais 400 kV substations to raise Iberian–European exchange capacity to 5,000 MW. The plan notes the need for system studies by Red Eléctrica and RTE to assess internal reinforcements and technical requirements for the HVDC connection.

On 18 March 2020, Inelfe, developer of the Biscay Gulf interconnector between Spain and France, issued a tender call for geophysical and geotechnical survey services in the Biscay Gulf, seeking support to determine detailed seabed conditions and stratigraphy. The investigations, including surface and sub-surface geophysical work and geotechnical campaigns such as CPTs and coring, are intended to inform the installation of the submarine power cables for the interconnector.

On 18 October 2019, following seabed investigations that showed no stable route under the Capbreton Canyon, RTE and Red Eléctrica launched new studies to bypass the canyon and define an alternative route for the Bay of Biscay interconnection that would ensure long-term stability of the power line.

By early May 2019, RTE and Red Eléctrica had completed extensive geological studies of the seabed for the Biscay Gulf interconnection, whose latest campaign revealed soil instability very close to the Capbreton Canyon in French waters, prompting reconsideration of the planned submarine route.

From 2017 onward, Red Eléctrica and RTE jointly launched and conducted common technical studies for the Biscay Gulf interconnection to analyse how the new 2,000 MW HVDC link would affect the behaviour of the Spanish and French electrical systems and to identify any necessary internal reinforcements and HVDC technical requirements to ensure 5 GW of exchange capacity.

In 2016, the EU approved additional Connecting Europe Facility funding of up to €6.25 million for further studies on the new Atlantic electrical interconnection between Spain and France via the Bay of Biscay, complementing earlier study support to advance project development.

In 2014, the Bay of Biscay interconnector received up to €3.25 million of EU support under the Connecting Europe Facility to fund studies for a new Atlantic electrical interconnection between Spain and France, helping to prepare the technical and regulatory basis for the PCI project.

In 2014, initial studies for a new Atlantic electricity interconnection between Spain and France, corresponding to the Bay of Biscay project, were undertaken with support from the EU’s Connecting Europe Facility, which allocated up to EUR 3.25 million for these early-stage investigations.

The Bay of Biscay electricity interconnection between Gatika in Spain and Cubnezais in France was listed by the European Union as a Project of Common Interest (PCI), recognising its strategic role in increasing Spain–France interconnection capacity and supporting EU energy market integration. Subsequent European Commission factsheets and funding for studies and works under the Connecting Europe Facility confirm this continued PCI status.

Electricity Interconnection France-Spain (Inelfe), a joint venture equally owned by Spanish transmission operator Red Eléctrica and French operator RTE, was established following the 2008 Zaragoza Agreement between the Spanish and French governments to develop and operate cross-border interconnections, including the Bay of Biscay/Biscay Gulf HVDC link that will raise exchange capacity between the two countries to 5,000 MW.