The first of its kind in the country, and one of only six worldwide, the 60-metre-high machine will not be fixed to the ocean floor as with previous wind turbine models, but will float on a huge platform, as explained by French news source 20 Minutes.
It will be held in place by a number of 33-metre-long, nylon tethers, and connected to an existing, high-tension underwater cable.
Created by the company Floatgen with French start-up Idéol, plus support from Bouygues Travaux Publics and the Ecole Centrale de Nantes, it has been 18 months in the making.
Set to be officially launched this lunchtime (Friday), it will soon be installed 20km off the coast of Croisic (Loire-Atlantique), and - once fully operational from January 2018 - will have the capacity to produce enough electricity to power the equivalent of 2,000 homes for a year.
There are 3,000 other sea turbines in use all over the world, but only six other floating ones in total - four in Japan, one in Norway, and one in Portugal.
“Floating turbines have the advantage of not being constrained by sea depth, so they can seek stronger winds, without any visual impact from the coast. This has massive potential,” explained the CEO of Idéol, Paul de la Guérivière, speaking to 20 Minutes.
Six other similar projects in France are in the pipeline, including those at La Baule, Fécamp (Seine-Maritime) and Courseulles-sur-Mer (Calvados), which are expected to go into service in 2021.
Sign up to our free weekly e-newsletter
Subscribe to access all our online articles and receive our printed monthly newspaper The Connexion at your home. News analysis, features and practical help for English-speakers in France