First Offshore Wind Substation Installed in France

Belgian offshore installation firm DEME Offshore said Thursday it had installed the first offshore wind substation in France, at the Saint-Nazaire offshore wind farm site. The installation of the 2,100-ton substation was carried out by Allseas' giant Pioneering Spirit vessel.

This was also Allseas’ first job for the offshore wind industry, and it is the first “complete” installation job executed by Pioneering Spirit, as it installed the 50-meter tall supporting structure last weekend.

"The speed and ease with which she can transport and install large high-voltage converter platforms in all conditions makes Pioneering Spirit a perfect fit for the offshore wind energy industry," Allseas, which DEME contracted for the job, said.

The electrical substation was constructed by a consortium including Atlantique Offshore Energy, the business unit of Chantiers de l’Atlantique dedicated to Renewable Marine Energies, GE Grid Solutions, and DEME Group’s French subsidiary SDI. 

The 480 MW Saint-Nazaire offshore wind project is being developed by EDF Renouvelables and EIH S.à r.l, an indirect subsidiary of Enbridge Inc., and CPP Investments. Saint-Nazaire, scheduled to be operational in 2022, will be the first commercial offshore wind farm installed in French waters. The contract for the substation was awarded in 2019.

The 480 MW substation is (H) 15 m x 27 m x 39 m, while the jacket, installed last weekend, is 26 m x 26 m x 48 m (H) and weighs 1,250 tons.

DEME Offshore carried out the transport and installation of the OSS, including the offshore pre-piling works. Chantiers de l’Atlantique was responsible for the topside and jacket foundation design, manufacturing, and commissioning. GE Grid Solutions is responsible for the high voltage electrical equipment and protection control systems design, manufacturing, and commissioning.

The same consortium responsible for Saint-Nazaire has also been selected by Eoliennes Offshore des Hautes Falaises et Eoliennes Offshore du Calvados to design, manufacture and install the electrical substations for the Fécamp and Calvados (Courseulles-sur-Mer) wind farms in Normandy, France.

Also, Allseas sees more work ahead for its Pioneering Spirit vessel. 

"Aside from playing a key role in the installation of large transformer stations, we also see a future role for our game-changer in the installation of next-generation turbines and monopiles, so heavy and large that they greatly benefit from a vessel of Pioneering Spirit’s capabilities for transportation and installation," Allseas said.