DEME Installs Dieppe Le Tréport Offshore Substation

July 2, 2025, by Adnan Memija

The offshore substation (OSS) of the 496 MW Dieppe Le Tréport offshore wind farm has been installed at its designated location 15 kilometres off the city of Le Tréport and 17 kilometres off the city of Dieppe in France.

Dieppe Le Tréport substation — Credit: Eoliennes en Mer Dieppe Le Tréport (EMDT)

The substation, which was designed and built by Atlantique Offshore Energy, the Chantiers de l’Atlantique division dedicated to marine energy, arrived in Le Havre in June.

Its foundation, a steel jacket structure, was supplied by Navantia in Spain, and DEME carried out the installation operation at sea with its installation vessel, Gulliver.

The jacket is nearly 54 metres tall and weighs approximately 1,900 tonnes. It was entirely built at the Puerto Real shipyard.

“This extremely precise and well-prepared phase ends 24 months of construction of the Dieppe-Le Tréport topside at our Saint-Nazaire site. Through this project, we continue to strengthen Chantiers de l’Atlantique’s position as a key player in marine renewable energy in Europe,” said Frédéric Grizaud, Director of the Marine Energies Business Unit at Chantiers de l’Atlantique.

“We are thankful to Eoliennes en mer Dieppe Le Tréport (EMDT) for their trust, as well as to all the teams involved. Now their mission goes on with the completion of offshore works, testings, and then the energization of the substation.”

Substation Topside for 496 MW French Offshore Wind Farm Arrives in Le Havre

Grid Connection

Once operational, the substation will collect the renewable electricity generated by Dieppe Le Tréport’s 62 Siemens Gamesa 8 MW turbines and transfer it to shore via the grid connection infrastructure developed by the French transmission system operator (TSO) Réseau de Transport d’Électricité (RTE).

The project is developed by Eoliennes en Mer Dieppe Le Tréport (EMDT), a company whose shareholders are Ocean Winds, Sumitomo Corporation, and Banque des Territoires.

“Following the first power of the EMYN project last month and our continued progress on EFGL, the successful installation of the Dieppe – Le Tréport offshore substation is another significant milestone for Ocean Winds, and a further demonstration of the momentum building across France’s offshore wind sector,” said Marc Hirt, Country Manager for Ocean Winds in France.