The losses in converting wind - mechanical - electrical - mechanical, and the electrical transmission losses make this arrangement inefficient. Why not combine the desalination equipment with the wind turbine structure, and pipe the fresh water ashore.

Wind turbines tend to be low-speed high-torque machines, poorly suited to generating electricity, but ideal for driving a compressor for reverse osmosis desalination.

Desalination equipment is pretty compact - compact enough to fit inside the wind turbine tower, so no additional structure is required.