Parc éolien en mer de Dieppe

Location

The Dieppe-Le Tréport offshore wind farm is located in the English Channel, approximately 17 kilometers off the coast of Dieppe and 15.5 kilometers offshore from Le Tréport, in the Normandy region of France. The site spans an area of approximately 110 km², with water depths ranging between 14 and 25 meters.

Developers and Ownership

The project is developed by Éoliennes en Mer Dieppe Le Tréport (EMDT), a special purpose company formed by a consortium of:

• Engie (31%)
• EDP Renewables (29.5%)
• Sumitomo Corporation (29.5%)
• Caisse des Dépôts et Consignations (10%).

Capacity and Turbines

The wind farm will consist of 62 Siemens Gamesa D8 8MW offshore wind turbines, each with an 8MW capacity. These turbines are based on Siemens Gamesa’s proven offshore direct drive platform. Each turbine has a rotor diameter of 167 meters and blade lengths of 81.5 meters, with a swept area of 21,900 m². The turbines are designed to operate at 690V and 50Hz frequency and are capable of producing electricity when wind speeds exceed 11 km/h, automatically stopping when wind speeds exceed 108 km/h.

Production and Impact

The wind farm has an installed capacity of 496 MW and is expected to generate an average of 2,000 GWh of electricity per year. This amount of electricity is sufficient to meet the electricity needs of approximately 850,000 people. The turbines are expected to operate at peak power for about 40% of the time each year.

Infrastructure

The project includes several key infrastructure components:

• Foundations and Supporting Structures: The turbines and the offshore high voltage station (OHVS) will be mounted on jacket-type structures supported by driven pile foundations.
• Inter-array Cables: The turbines will be connected via an inter-array network consisting of 33 kV AC cables.
• Offshore Substation: Power will be gathered and transferred to an offshore substation through the inter-array cable network.
• Grid Connection: The electricity will be transmitted onshore through two 225 kV subsea cables, followed by a 3.5 km underground connection to the Grande-Sole electrical substation. From there, it will be connected to the existing Penly substation via a 400 kV underground link for distribution across the region.

Contractors and Engineering

Several companies are involved in the project:

• Owner’s Engineer: A consortium composed of ODE and DORIS Engineering was contracted for the installation of wind turbine generators and management of marine construction.
• Turbine Supply: Siemens Gamesa, through its subsidiary Adwens France, was awarded the turbine supply contract.
• Inter-array Cables and Offshore Substation: IMDC, in partnership with Tractebel, is responsible for the inter-array cables and the offshore substation.
• Geotechnical Survey: Fugro carried out the geotechnical survey on the site from July to October 2018.
• Submarine Cable Laying: Arteliay was contracted to conduct submarine cable laying and landfall works for the wind farm’s electrical connection.

Construction and Timeline

Construction began in 2019, following environmental approval and site clearance from the French Agency for Biodiversity (AFB) and the Prefecture of Seine-Maritime in February 2019. As of September 2024, the construction has reached a milestone with 50% of the piles now installed, with the Apollo jack-up vessel from DEME Group conducting the initial piling operations and the Sea Challenger arriving to carry out drilling work where piling is impossible.

Environmental Considerations

The project has undergone several environmental studies to assess its impact. These studies include ecosystem assessments and geotechnical investigations to ensure minimal disruption to the marine environment. An ecosystem approach has been promoted to collect data on the different ecosystem compartments of the site, adopting an Ecopath model to analyze the ecosystem structure and functioning.

Investment and Economic Impact

The project is estimated to require an investment of €2 billion ($2.27 billion). The wind farm is expected to contribute significantly to France's renewable energy targets and help reduce fossil fuel emissions in line with European and global climate change mitigation efforts.

Operational Life

The estimated operational life of the wind farm is 20 years, with commissioning planned for 2025, although initial plans had suggested a commissioning date of 2021.