Floating wind power is accelerating its deployment off the French coast.

Three floating wind turbines installed off the coast of Leucate, in the Aude, and Barcarès, in the Pyrénées-Orientales, are undergoing their final tests before their planned commissioning this week.

Each with a capacity of 10 megawatts (MW), they form the pilot farm for the Gulf of Lion Floating Wind Turbines (GFLT). With a total capacity of 30 MW, the park is expected to produce the equivalent of the annual electricity consumption of a city of 50.000 inhabitants.

The three turbines, 186 meters high, are operated by Ocean Winds, a joint venture dedicated to offshore wind power created by the French group Engie and the Portuguese EDPR.

For Marc Hirt, Managing Director France of Ocean Winds, this pilot farm is "one of the few parks in the world" equipped with turbines installed on floats.

This pilot farm is intended to test a still-emerging technology. According to Ocean Winds, its large-scale deployment is necessary to industrialize the manufacturing of the floats and reduce costs.

A technology adapted to deep-sea areas

In Europe, approximately 6.000 offshore wind turbines currently rest on the seabed. This so-called "bottom-mounted" technology benefits from significant experience, but its use is hampered by the depth of certain areas.

Marc Hirt clarifies: "The technique of offshore wind turbines is well-established, but it has its limitations: the depth of the seabed."

Installed on floating structures anchored to the seabed, floating wind turbines can be deployed further from the coast, in areas where installing fixed foundations would be difficult or too expensive.

Marc Hirt adds: "In areas with significant depths, floating wind turbines allow us to move away from the coast and avoid criticism regarding the landscape."

According to the head of Ocean Winds, the potential for installing floating wind turbines "is unlimited in France and around the world."

The development of onshore wind power is simultaneously encountering various constraints. In France, the presence of civilian and military radars "prevents increasing the height of wind turbines" beyond 130 to 150 meters, as Samuel Renard, managing director in charge of renewable energies in France at Engie, recently pointed out.

Steel floats anchored at a depth of 70 meters

EFGL's three wind turbines rest on steel floats that are still prototypes. Each structure is held by three chains and anchored at a depth of 70 meters, approximately 16 kilometers from the coast.

The amount invested in the project, launched after ten years of preparation, has not been disclosed. The electricity produced will be sold to EDF at the price of 240 euros per megawatt-hour, a price significantly higher than the market price.

Public investment also plays a significant role in this type of project. In particular, several tens of millions of euros have been allocated, with the support of the Occitanie Region, to develop a "heavy-duty wind turbine quay" in Port-La-Nouvelle. This infrastructure is essential for assembling the floating platforms and wind turbines.

Banque des Territoires, a subsidiary of Caisse des dépôts, is also a co-shareholder of the pilot farm alongside Ocean Winds, which holds the majority stake.

Three pilot farms in the French Mediterranean

Two other pilot floating wind turbine farms are located in the French Mediterranean:

• Provence Grand Large, off the coast of Marseille, is already in service and develops a power of 25 MW;
• EolMedThe wind farm, operated by the French company Qair, is located off the coast of Gruissan, in the Aude region. With a capacity of 30 MW, the wind farm has been energized, but is not yet operational.

EolMed is located a short distance from the EFGL park. These pilot installations are intended to provide technical feedback before the deployment of larger-scale commercial projects.

New business projects expected

In mid-October, the AO10 tender will collect bids for several offshore wind projects representing a total capacity of 10 gigawatts (GW), half of which will be floating wind turbines. The sites concerned extend from the English Channel to the Gulf of Lion, passing through Brittany and Oléron.

The AO6 project of the Floating Wind Turbines of Occitanie (EFLO), awarded to Ocean Winds, plans for the installation of a maximum of 19 floating wind turbines at the beginning of the 2030s.

Located 25 kilometers off the coast of Hérault and Aude, this park is expected to reach a total capacity of 250 MW and will be able to supply electricity to approximately 500.000 people.

With its 2.800 kilometers of coastline, France committed to developing offshore wind power in 2009. It aims for an installed capacity of 45 GW by 2050.