Wind

Ocean Winds eying 21MW turbine for landmark floating wind project

Siemens Gamesa prototype launch has strengthened the base case for 21MW machines on a first commercial-scale floating wind project in the Mediterranean

One of the three foundations used on EFGL, a pilot floating wind project in France, but something much bigger is planned for a commercial scaling up of this project.
One of the three foundations used on EFGL, a pilot floating wind project in France, but something much bigger is planned for a commercial scaling up of this project.Photo: Ocean Winds / Principle Power
Senior Correspondent

Ocean Winds intends to deploy giant 21MW wind turbines on a flagship floating offshore wind project in the French Mediterranean and also has a preferred choice on which hull design it will use for the foundations.

The Engie-EDP Renewables joint venture is the early stage of development of Eoliennes Flottantes d’Occitanie (EFLO), a 250MW floating project awarded in 2024 and set out its base case plans, including turbine size and hull design, when the bid was submitted.

Although final decisions and the procurement process are still some time away, these base case choices have strengthened, according to Marc Hirt, Ocean Winds’ country manager for France, who told Recharge that the company is aiming to use 21MW turbines on the project.

Asked about readiness for turbines on such a scale, Hirt mentioned Siemens Gamesa’s giant SG-DD-276 prototype as strengthening the case.

In April, the German-Spanish turbine-making giant confirmed that it had assembled a giant prototype at a Danish test centre, lifting a veil of secrecy that had been surrounding the project.
A prototype certificate issued by the Danish Energy Agency for the SG DD-276 model confirmed that it has a power rating of 21.5MW and a rotor diameter of 276 metres.
Bigger turbines can reduce levelised energy costs in offshore wind projects, but the Siemens Gamesa project is also a response to considerable investment in 20MW+ turbines by Chinese companies.

Flourishing partnership

For the EFLO hulls, Ocean Winds is leaning toward a decision to use a scaled-up version of Principle Power’s steel submersible WindFloat design.

Ocean Winds has already used versions of the floater specialist's design on WindFloat Atlantic, a 25MW pre-commercial project in Portugal and, more recently, on the 30MW Eoliennes Flottantes de Gulf of Lion (EFGL) pre-commercial array, which is located close to the future EFLO site, but in shallower waters.

Ocean Winds and Principle Power also worked together on the very first prototype of the latter's WindFloat design, which operated in Portugal between 2011 and 2016. The pair are also working together in originating the 1.3GW KFWind portfolio in South Korea currently.

“We based our bid for the EFLO project on the concept of a PPI (Principle Power) foundation and a 21MW turbine. We have not reached a final decision yet, but we are still thinking this way today,” Hirt told Recharge.

“We are very satisfied with PPI,” he added.

Hirt stressed that no options are being excluded at this relatively early stage.

Permitting applications for the project are due to be submitted next month but a new “flexible envelope” procedure allows key decisions to be made further forward in the development process than used to be the case in France.

So final selection of turbines and floater design could be any time before a final investment decision (FID), and will involve a competitive process, meaning the final outcome could still be years away.

FID for this project is currently anticipated around 2028–2029, depending on any challenges to the authorisations. Construction is not expected to begin until the end of the decade, the company indicated.
“It is not yet possible to provide precise dates for the start of the procurement process for turbines, cables, or other long-lead items, but it is reasonable to expect that such processes will commence in the lead-up to the FID period,” a spokesperson for the company told Recharge.

New hull design

But project documents already suggest that a new variation of the Principle Power hull design will be used, offering a centralised hull positioning for larger and "stiffer" turbines.

On the other hand, the same documents describe a project with “up to 19 wind turbines” showing that deployment of machines with significantly lower rating than 21MW are still being considered.

The EFLO project originates from an area that was known as Narbonnaise 1 when it was included in France’s AO6 wind tender. The wind farm will be located at an average water depth of 92 metres, at least 25km from the coast in the Gulf of Lion.

Ocean Winds is also planning to bid for a southern extension of EFLO in the ongoing AO9 wind tender, which is supposed to reach its conclusion by the end of this year.

The area currently on offer, called Narbonne 2, is one of three floating wind extension areas on offer in the AO9 round.

Concern has been growing that publication of the enabling regulations that are required to stage AO9 is starting to run late.

Bidding is supposed to take place four months after publication of the detailed tender rules.

(Copyright)

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Published 10 September 2025, 08:10Updated 10 September 2025, 08:10
Ocean WindsFrancePrinciple PowerMediterraneanENGIE