Les Éoliennes Flottantes du Golfe du Lion (EFGL)

Les Éoliennes Flottantes du Golfe de Lion (EFGL) project, located 16 km off the coast of Leucate and Le Barcarès, is the second floating wind pilot project in the French Mediterranean Sea. The project represents a significant step toward the first commercial-scale deployment in Europe.

EFGL consists of three WindFloat® floating foundations designed by Principle Power. Each foundation supports a Vestas V164-10 MW turbine. To date, these are the largest wind turbines installed on a floating foundation.

The project features the third-generation of WindFloat® technologies and reflects more than a decade of operational experience across multiple floating wind projects, which includes the 2 MW WindFloat 1 pilot to the 25 MW WindFloat Atlantic in Portugal and the 48 MW Kincardine Offshore Wind Farm in Scotland.

Lessons learned were incorporated into Principle Power’s design principles, engineering processes, and technical specifications to support standardization, modularity, and industrialization. As a result, EFGL directly benefits from the WindFloat® technology evolution and now contributes additional insights to the development of the 15-20+ MW generation WindFloat®.

Principle Power has maintained a presence in France since 2013, with approximately one third of its workforce based in Aix-en-Provence, supporting domestic and internal markets. EFGL is a reference project whose experience informs upcoming developments in France.

The project involves multiple French industrial and port stakeholders. WindFloat T foundations were fabricated at Eiffage Métal’s Fos-sur-Mer yard, which was converted from an oil & gas manufacturing facility into a floating wind hub.

Following assembly and loadout, the foundations were offloaded at Fos-sur-Mer and then subsequently wet towed to Port-La-Nouvelle facility. The port served as a focal point for floating offshore wind activity in the French Mediterranean, including turbine integration and pre-commissioning.

Port infrastructure and logistics services were provided through agreements with Euroports France. Onshore lifting and transport were supported by Mammoet, with additional handling and engineering support from NaRval Solutions, Vulcain Ingénierie, and Groupe Foselev.

EFGL is located within the Natural Park of the Gulf of Lion and is the first floating offshore wind project installed in a marine reserve. The project was developed in coordination with national and local authorities and non-governmental stakeholders to ensure responsible sitting, positive socio-economic impacts, and a minimal environmental footprint.

In preparation for WindFloat® installation, a Biodiversity Observation Buoy (BoB) was deployed in June 2019 at the future project site. The objective was to establish a baseline characterization of marine biodiversity and observe colonization of artificial structures ahead of WindFloat® installation.

The buoy was designed by Principle Power and equipped with 16 Biohut® artificial habitats developed by Ecocean, under the guidance of scientists from the Marine Ecosystems Research Centre of the University of Perpignan, the Chorus Institute, and Ecocean. Biohut® structures offer shelter for juvenile fish during the post-larval stage, providing protection from predators and supporting local marine life around the structures.

The mission concluded in 2023. Observations confirmed species abundance and richness comparable to coastal sites, no invasive species detected, high densities of mollusks and sea urchins, and increased fish vocalizations.

Building on these observations, 32 Biohut® units were installed on the lower main beams of one WindFloat® foundation. Data collected over time will be compared with an unequipped WindFloat® foundation to assess differences in marine colonization.

Principle Power supported the integration of the Biohut® systems by assessing their effects on platform performance, corrosion protection, and structural behavior. The assessment confirmed that the Biohut® units have a negligible influence on platform response, and that all systems, including ICCP and cabling, continue to operate as designed.

Overall, the installation of the Biohut® systems illustrates how environmental monitoring initiatives can be integrated into floating offshore wind projects to support ongoing observation of interactions between marine ecosystems and offshore energy infrastructure.