Floating wind farms and Replacement of heavy components. Where do we go?

The replacement of heavy components from floating wind turbines is going to be the pebble in the shoe of the floating wind sector for the years to come.

Imagine a blade repair campaign for a full wind farm, due to excessive wear for instance. This happens.

For bottom fixed wind farms the job is done by a single jack-up, with a blade repair shop prepared on deck, going from 1 turbine to another, dismantling one blade and replacing it immediately by a repaired one from a previous turbine, until the full rotor is repaired and the JUV moves to the next location. For the wind farm, the downtime per turbine is reduced to a minimum and the cost is mainly the one of a JUV in capacity to lift a blade to hub height.

Now imagine the same for a floating wind farm and count the downtime due to the “Tow to Port” option: mooring and cable disconnection, associated array procedures, tow to port, 3 blades replacement, tow to wind farm and reconnection, considering the technical uncertainties due to cabling re-connection. And multiply it by the number of turbines…

There are several tracks being explored to “remove the pebble”

1. Simplify and make more reliable the disconnection/reconnection of the floating foundation
2. Development of Floating crane vessels, able to cope with the relative motions of both the vessel and the floating foundation
3. Deployable lifting equipment, where some quite interesting concepts are being developed requiring significant interfaces with the floating foundations and turbines.
4. WTG design “floating optimization” that would focus on removing the need for large cranes for the replacement of heavy components.

NaRval strongly believe in the options 3. and 4. but they can’t fly if the design of the floating foundation and/or the wind turbine has not integrated the potential interfaces. Feel free to contact vincent.cazenave@narvalsolutions.fr to exchange views on that matter.