I.6 Floating offshore wind turbine installation

Function

Tow-out of an assembled floating offshore wind turbine to site, hook-up to mooring lines and array cables, and the final commissioning of the installed floating offshore wind turbine.

What it costs

About £24 million for a 450 MW floating offshore wind farm.

Who supplies them

Boskalis, Bourbon Offshore, Maersk, Saipem and Seajacks.

An assembled floating offshore wind turbine starting its tow-out for the WindFloat Atlantic project.
An assembled floating offshore wind turbine starting its tow-out for the WindFloat Atlantic project. Photo of the WindFloat Atlantic project courtesy of Principle Power/Ocean Winds.

Key facts

Floating offshore wind turbines are towed from the construction port to the offshore site with a primary AHV and smaller support vessels.

The floating offshore wind turbine is hooked-up to a pre-installed mooring spread once it arrives at site with the aid of the towing vessels.

The array cable is either connected to the floating offshore wind turbine once it arrives at site or later during post lay operations.

Tow-out and hook-up is expected to be performed by an offshore EPCI contractor, because the vessels are the largest part of the cost build up.

Final commissioning involves commissioning the assembled floating substructure with its mooring and array systems, and the final commissioning of the wind turbine. It is expected to be split between the EPCI contractor for the hook-up and floating substructure, and the wind turbine supplier for the wind turbine.

Guide to a Floating Offshore Wind Farm