All three WindFloat® platforms installed for EFGL, the largest floating wind turbines to be installed at sea

All three floating wind platforms for the Les Éoliennes Flottantes du Golfe de Lion (EFGL) project have successfully been installed following wind turbine integration and pre-commissioning activities performed at Port-la Nouvelle. Located 16 km off the coast of Leucate and Le Barcarès, the project marks the second small commercial floating wind project in the French Mediterranean and a significant step toward commercial-scale deployment in Europe.

EFGL is sponsored by Ocean Winds and Banque des Territories and features three WindFloat® foundations designed by Principle Power and fabricated by Eiffage Métal. These foundations hosts three Vestas V164-10 MW turbines, which are the largest wind turbines ever installed on a floating foundation, and are expected to generate enough electricity to provide power for approximately 50,000 inhabitants each year.

The project is supported by a non-recourse loan from private banks including KfW IPEX-Bank, Crédit Agricole CIB, Banco Santander, S.A., Mizuho Bank as well as the European Investment Bank and Danish ECA EKF. The financing structure is one of the first for floating wind and demonstrates the bankability of the technology, paving the way for larger projects, where project Capital Expenditures are expected to grow into the multi-billion range.

From design into execution

Les Éoliennes Flottantes du Golfe de Lion (EFGL) feature the third-generation WindFloat® technologies and reflect over a decade of operational experience designing floating wind foundations in diverse marine environments.

Engineers at Principle Power have built on the experience of the 2 MW WindFloat 1 pilot in Portugal, the 25 MW WindFloat Atlantic project in Portugal, the redeployment of the 2 MW pilot to Scotland, and the 48 MW Kincardine Offshore Windfarm in Scotland to design a coupled systems that delivers optimal performance and energy production for minimal structural weight.

Each project has contributed incremental design optimizations to the next generation WindFloat® technologies, supporting standardization, modularity, and industrialization. Lessons learned have been integrated into Principle Power’s core design principles, engineering processes, and technical specifications, enabling teams to proactively address the challenges associated with scaling for industrial deployment.

EFGL has directly benefited from the WindFloat® technology evolution and now contributes further insights to the development and optimization of the 15-20+ MW generation WindFloat® - WindFloat F, WindFloat T, and WindFloat center Column Designs WindFloat TC and WindFloat FC – which have already been selected for several commercial projects. These 4th generation designs are outfitted with features that will deliver streamlined execution plans, increased power production, and high levels of reliability.

From fabrication to installation

Principle Power’s WindFloat T foundations for Les Éoliennes Flottantes du Golfe du Lion (EFGL) were fabricated at Eiffage Métal’s Fos-sur-Mer yard. The process involved connecting the upper and lower main beams to three column modules, followed by outfitting, pre-commissioning, and loadout.

The three WindFloat T foundations were offloaded to Port-La Nouvelle, which was upgraded by the Région Occitanie to support floating wind operations. The Wind Turbine integration operation started when the WindFloat® units arrived at the integration draft and were moored to the quay.

The towers, nacelles, and blades were then installed and mechanically completed one-by-one. The tower is divided into three main sections, each ranging from 25 to 35 meters in height and weighing around 600 tons in total. The 380-ton nacelle was lifted into place to achieve an operating hub height of 104 meters above sea level. Finally, the three 80-meter blades, each weighing 34 tons, were installed in individual lifts.

These components were lifted onto the lightweight WindFloat® platform, which have primary steel weights of approximately 2,000 tons, using Mammoet’s Terex Demag CC 8800-1 crawler crane. The Hull Trim System was used to level the platform during the operation for safe and even transfer of loads from the onshore crane to the WindFloat®.

Once integration and pre-commissioning at port were completed, the platforms were towed 16 kilometers offshore Leucate and Le Barcarès and conducted to the preinstalled catenary mooring system. Offshore hook-up activities were carried out by the Skandi Tender and supported by a fleet of assistance and surveillance vessels operating under stringent safety protocols.

Final works now underway include the installation of inter-array and export cables by SDI, and the grid connection by RTE (Réseau de Transport d’Électricité). Commissioning of the project is scheduled to be concluded by the end of 2025. Once operational, EFGL will feature the most powerful wind turbines ever to generate power on floating foundations, with a power rating of 10 MW and a maximum tip height of 186 meters.

A blueprint for commercial scale delivery

EFGL is a real-world demonstration of floating wind deployment. From early stages through fabrication, integration, and offshore installation, the project has validated technologies for 10 MW turbines, port logistics, marine coordination, execution plans, and local supply chains.

As the first floating offshore wind farm to be installed in a marine protected area, the project has pioneered many innovative nature-positive approaches, such as the deployment of the Biodiversity Observation Buoy and Biohuts, to maximize harmony with the natural environment and collect date that can inform future projects. Finally, the project collaborated with stakeholders, including local fisherman’s collectives, to ensure maximum benefit for local communities.

These elements are critical elements for the success of upcoming commercial scale projects in the French Mediterranean, which are central to France’s goal of reaching 40 GW of offshore wind by 2050, and is a reference point globally that is already informing projects as far afield as Korea and Japan.