Belgium-based energy infrastructure group Dredging, Environmental and Marine Engineering (DEME) has announced the installation of the first offshore substation (OSS) at the 480MW Saint-Nazaire offshore wind farm in France.

The OSS weighs 2,100t and was built by a consortium of companies, including Atlantique Offshore Energy, GE Grid Solutions and DEME Group’s French subsidiary, SDI.

The wind project is being developed by EDF Renouvelables, EIH and CPP Investments. It is expected to come online next year.

One operational, Saint-Nazaire will be the first commercial offshore wind farm installed in French waters.

The substation contract was awarded in 2019.

DEME Offshore Renewables general manager Bart De Poorter said: “The construction and installation of the OSS is the result of strong cooperation between the consortium members, with each partner bringing its expertise and highest level of execution to the project, enabling us to meet the stringent quality, safety and environmental standards.

“As a result of this cooperation, we were able to design, fabricate and install the OSS in only 26 months, which is an incredible achievement and testament to the collaboration with our partners.”

GE Grid Solutions’ ACS division has designed and integrated the high and medium voltage systems.

They include five 220kV gas-insulated switchgears delivered by Aix Les Bains, France, as well as two 220/33kV transformers, two SCADA systems, a 33kV gas-insulated switchgear and a telecommunication system.

Chantiers de l’Atlantique is responsible for the design, manufacturing and commissioning of the topside and jacket foundation.

GE Grid Solutions is handling the design, manufacturing and commissioning of the high voltage electrical equipment and protection control systems.

DEME Offshore transported the OSS and installed it at the project site.

The consortium has also secured a contract to design, manufacture and install the electrical substations for the Fécamp and Calvados (Courseulles-sur-Mer) wind farms in Normandy.