On 12 July, STX France’s Saint-Nazaire yard began assembling the substation for the Arkona offshore windfarm being developed by German power utility E.ON, Norwegian group Statoil and German company 50Hertz. The Baltic windfarm, comprising sixty 6-MW Siemens turbines generating enough electricity to power 400,000 homes, is scheduled for completion in 2019.
The 385-MW substation, for delivery in Q2 next year, will be one of the most imposing structures of its type anywhere in the world.

(© Bernard Biger - STX France)
Known at the yard as P34, this substation is the first to be designed entirely by STX France following several years’ R&D on weight-saving and other innovations. The Arkona windfarm will have the biggest ac substation ever assembled as a single block. The topside will be installed by the Seaway Heavy Lifting vessel Oleg Strashnov on a massive 60-m-tall jacket-type foundation, hence the strict weight limit of 4000t.
A second substation is currently under construction at the Saint-Nazaire yard. This 309-MW unit for Belgium’s Rentel windfarm comprising forty-two 7-MW Siemens turbines is scheduled for delivery to the Otary consortium by the end of the year.
Building on its growing experience in EPCI (engineering, procurement, construction and installation) contracting, STX France recently introduced a new substation design concept (see STX scalable offshore substations).
Original by Vincent Groizeleau, translated and adapted by Steve Dyson