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 £11 million for a 450 MW floating offshore wind farm.

Who supplies them

Boskalis, DEME, Heerema, Saipem, Scaldis Salvage & Marine, Seaway 7, Van Oord and ZPMC.

Offshore substation installation often forms part of the substation supply contract.

Topside structure of an offshore substation being installed onto a jacket foundation.
Topside structure of an offshore substation being installed onto a jacket foundation. Image courtesy of ScottishPower Renewables. All rights reserved.

Key facts

Fixed offshore substation installation is a heavy lift operation (minimum of 2,000 t) requiring vessels with sufficient crane capacity. Vessels with the necessary lift capacity often do not have the deck space to accommodate a substation platform. The substation is therefore floated out of the 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.

The installation process for floating offshore substations will be similar to the process described for installing floating substructures for floating offshore wind turbines (see I.6 for further information).

Guide to a Floating Offshore Wind Farm