Removal and shipment to shore of cables.

What it costs

About £33 million for a 450 MW floating offshore wind farm.

Who supplies them

Expected to be the same as the cable installers.

In addition, companies such as CRS Holland, Pharos Offshore and Subsea Environmental Services can carry out subsea cable recovery.

Key facts

The value, especially of the main conductor material in array and export cables, is such that it is likely to cost effective to remove the cables.

There will be no significant differences in the process of decommissioning subsea cables for floating offshore wind farms compared to fixed offshore wind farms.

Cables will be disconnected at each end. They are then pulled from the sea bed and wound on to drums or cut into short sections for storage on the decommissioning vessel. Cable accessories, including any buoyancy modules or cable protection installed, will be removed with the cable. The method of gripping and pulling the cable will depend on how the cable is fixed to the sea bed, the ground conditions and burial depth (if buried). For buried cables in sandy conditions the approach is likely to involve fluidising the sea bed while the cable is pulled. The industry is likely to develop new tools for the process.

Particular care is needed at cable crossings with other power or telecommunications cables to avoid damage to functioning assets.

Guide to a Floating Offshore Wind Farm