The first offshore wind turbine in France

To date there are no fixed or floating offshore wind turbines in France. The project named Floatgen, managed by Ideol, Centrale Nantes and Bouygues TP is a 2 MW floating wind turbine and will be the first offshore wind turbine in France.

Construction work on the floating foundation took place between 2016 and 2017 in Saint Nazaire. It was inaugurated on October 13th and will soon be installed on the Centrale Nantes offshore test site, SEM-REV, to perform all tests in real conditions.


Innovation at all levels

Innovations is present throughout the project, whether it be the concept of a floating foundation in a square ring shape, or the offshore test site itself, or the type of concrete used for building the  floater, or the material used for the mooring lines.

The Centrale Nantes SEM-REV offshore test site, on which the wind turbine will be installed, is a research facility of international scope. It enables full deployment of prototypes which capture ocean energy (wind, waves) in real conditions at sea. Hence, researchers and professionals have access to the necessary tools to test prototypes before the commercial stage.

Key project data


Floater of 36 meters wide and of 9.5 m height (7.5 m draft). Equipped with the Ideaol's Damping Pool ® system and built in prestressed reinforced concrete by Bouygues TP


Model Vestas V80 2MW
Rotor diameter: 80 meters
Mast height including transition piece: 60 meters


Semi-taut mooring
6 synthetic fiber lines (nylon)


Installation on the first French offshore test site dedicated to multi-technologies and connected to the grid: a Centrale Nantes offshore test site, named SEM-REV


33 meters deep
12 nautical miles from the shore (22 km)


Particularly harsh conditions with maximum wave height (Hmax) of 16 meters

The floating foundation

June 2017
After a few months of construction in the Penhoët basin (Saint-Nazaire), the floating foundation that will equip the first offshore wind turbine in France was launched in September. The three assembled barges on which the floating foundation was built were towed to the Joubert lock, a dry-dock marking the entrance to the port of Saint-Nazaire. After the barges were immerged, the concrete hull was floated with perfect control. It was then towed towards the Quai des Charbonniers to await the addition of another part (a steel part at the interface between the floating foundation and the mast) and then the wind turbine.

To follow the construction live, the website of the project www.floatgen.eu shows images from a webcam on the building site.

The wind turbine

The Vestas 2 MW V80 that will be installed on the floater was unloaded on Saint-Nazaire harbour in June 2016. It will be slightly modified before being installed along the dock on the transition piece.

The mooring system

The elements of the anchoring system were assembled and installed on the Centrale Nantes test site, SEM-REV, in june 2017.

This very innovative system, developed by the start-up Ideol in collaboration with Centrale Nantes, consists in particular of 6 synthetic mooring lines (nylon) - a first for permanent anchoring of this dimension.

A project firmly anchored in Pays de la Loire region

70 direct jobs were created for the floater construction in Saint-Nazaire: the concrete used for the foundation developed by Ideol enables a construction close to installation sites. The construction techniques developed by Bouygues TP fit in the local economical context and adapt easily to harbour constraints.
LeBéon Manufacturing is leading the consortium for providing the mooring lines in nylon. A significant amount of parts were produced in their factory in Plouay (Morbihan). Partners of the Floatgen project made the choice to subcontract components, logistic activities, insurance and communication to providers based in the Saint-Nazaire area.

Installation on the test site

Three deep sea tugs were deployed during this delicate operation. Setting off late afternoon on Sunday 29th April, it took them about a day to transport the wind turbine to the SEM-REV test site. An additional three to four days are necessary for docking and connection to the export cable, which connects the wind turbine to the power grid onshore.
Floatgen will be tested under real operating conditions for 2 years. During the testing phase, the electricity produced by the turbine will be injected into the French power grid and Floatgen will supply enough electricity to meet the needs of a city the size of Le Croisic.

Floatgen: starting point of a serial deployment

The Floatgen project, the first wind turbine in France and first demonstrator of the floating foundation technology developed by Ideol, already provides and will continue to provide unique practical feedback to the partners of the consortium. Lessons will be learnt on building methods, installation and exploitation of the floating system and will be used as a commercial example for export. In July 2016, the French government selected a consortium led by Quadran with the Ideol floater foundation and Bouygues TP know-how, for the construction of a first offshore floating wind farm in the Mediterranean sea (4 units will be installed off Gruissan, one of the best sites for wind resources in Europe). This will be known as the EOLMED project.
Published on July 3, 2017 Updated on May 4, 2018