The 496MW Yeu-Noirmoutier wind farm is expected to produce 1,900GWh a year. Credit: Prysmian Group.
The Yeu-Noirmoutier offshore wind farm is expected to start operations in 2025. Credit: Sumitomo Corporation.
The wind farm will be installed with 62 Siemens Gamesa D8 wind turbines. Credit: Siemens Gamesa Renewable Energy.
The Cable Enterprise vessel is expected to be used to install the submarine cables for the project. Credit: Prysmain.

The 496MW Yeu-Noirmoutier wind farm is being built off the Pays-de-la-Loire coast of France by Éoliennes en Mer Îles d’Yeu et de Noirmoutier (EMYN).

As a joint venture (JV) between Engie (31%), EDP Renewables (EDPR, 29.5%), Caisse des Dépôts et Consignations (10%) and Sumitomo (29.5%), EMYN won the bid to develop the Yeu-Noirmoutier wind project, as well as the Dieppe-Le Tréport offshore wind farm, in June 2014.

Engie and EDPR formed a JV named Ocean Winds in July 2020. Ocean Winds comprises the offshore wind assets and projects in the pipeline for the two companies, including the Yeu-Noirmoutier project. EMYN is responsible for the construction, installation and operation of the offshore wind farm.

The project is expected to involve an estimated investment of €2bn ($2.27bn).

It will have an average annual production capacity of 1,900GWh, which is expected to be sufficient to meet the annual electricity demands of 800,000 people.

Expected to be commissioned in 2025, the wind farm will have an estimated lifespan of 25 years.

Location

The Yeu-Noirmoutier wind farm is being developed over an area of 83km², at a depth ranging between 19m and 36m, off the Pays-de-la-Loire coast.

The project will be located 11.7km from Yeu and 16.5km from Noirmoutier.

Yeu-Noirmoutier plant make-up

The offshore wind farm will comprise 62 Siemens Gamesa D8 offshore wind turbines with a capacity of 8MW each, spaced 1,000m and 1,600m apart. The turbine is based on the company’s proven offshore direct drive platform.

The project infrastructure will also include an offshore high-voltage station (OHVS).

Grid connection

The offshore wind grid connection will involve submarine and land-based cables. The produced electricity will be exported from the offshore substation through a 27km-long submarine cable route, followed by a 30km-long underground route. The cables will be able to export 500MW of clean, renewable energy.

The submarine section will consist of two 225kV high-voltage alternating current (HVAC) three-core extruded export submarine cables with single-wire armouring that will make landfall at La Barre-de-Monts beach.

The land section will include two 225kV HVAC extruded land cables circuits connecting the landfall area to the substation at Soullans. The electricity will be transmitted through the national grid.

Contractors involved

Global architecture, engineering and consulting company Ramboll performed the initial phase of basic design and front-end engineering design (FEED) for 62 jacket foundation structures for the project. The contract package also included services related to asset management, geotechnics, low-voltage design and corrosion protection.

Ramboll also used its aeroelastic load simulation capabilities to enhance the design during the initial phase of the project.

The Netherlands-based Primo Marine, an engineering consultant, conducted a feasibility study in 2015 for a horizontal directional drilling (HDD) crossing for the submarine cable section.

International engineering and consultancy company IMDC was engaged in 2017 to provide interpretation of the offshore geotechnical campaign of the wind farm, including laboratory testing.

Empire Engineering received a contract to manage the foundations and offshore substation packages for the Yeu-Noirmoutier wind farm in November 2017.

Réseau de Transport d’Électricité (RTE), the French transmission system operator, is responsible for the design, construction, management and operation of the 225kV submarine and land cables.

RTE awarded a contract worth more than €150m ($167m) to Prysmian Group (Prysmian) to develop the submarine and land export power cable systems for the project’s grid connection in March 2020.

Prysmian is responsible for the design, supply, installation and commissioning of the submarine cables, as well as the supply and jointing of the land cables circuits. The company will use Cable Enterprise, a cable laying vessel, to install the cables.

A consortium comprising DORIS Engineering and its subsidiary ODE was appointed to operate as the owner’s engineer for the wind farm in August 2017. The management of marine construction and installation of wind turbine generators (WTGs) are included in the contractual scope.

Siemens Gamesa Renewable Energy was chosen to provide WTGs for the project in September 2017.

Multi-disciplinary engineering and project management company Artelia was contracted to manage the electrical connection of the wind farm. The contract package includes technical assistance related to cable landfall works, detailed studies, support for contract award, and supervising designs and works.

Ocean Winds signed a capacity reservation agreement with Navantia for the construction of two jacket-type foundations and associated piles for the offshore substation of the project in June 2022.