Figure 51 Topside structure of an offshore substation being lifted onto a jacket foundation. Image courtesy of ScottishPower Renewables. All rights reserved.
Function
The installation of the offshore substation consists of the transfer of the substation from its quayside fabrication site and the installation on the foundation.
What it costs*
About £43 million for a 1 GW offshore wind farm.
Who supplies them
The installation often forms part of the substation supply contract.
Marine contractors include Boskalis, DEME, Heerema, Saipem, Scaldis Salvage & Marine, Seaway 7, Van Oord and ZPMC.
Key facts
Offshore substation installation is a heavy lift operation (2,000 t plus) requiring vessels with sufficient crane capacity. Vessels with the necessary lift capacity typically do not have the deck space to accommodate a substation platform. The substation is therefore floated out of the substation fabrication facility on a barge, usually directly to the wind farm site.
The substation foundation, which is installed prior to the topside structure, may be a monopile or a jacket and the installation may form part of the turbine foundation installation package.