O.3.1 Main component refurbishment, replacement, and repair (in-situ)


The major refurbishment, replacement, and repair of large components such as gearboxes, blades, transformers, generators, substructures, or substations at the wind farm.

Who supplies them

Boskalis, Fred. Olsen, Heerema, James Fisher Marine Services, Maersk, Saipem, Seajacks, Subsea 7, TechnipFMC, Van Oord and Ziton.

Key facts

All but the shallowest floating offshore wind farms are located at sites too deep to use jack-up vessels for main component refurbishment, replacement, and repair at site.

Nevertheless, on-board turbine service cranes can lift substantial loads from the nacelle to the floating substructure level to exchange or repair some major parts.

Exchange is carried out in one visit, followed by off-site refurbishment. Retrofit programmes are carefully planned to ensure effective vessel utilisation taking into account repair turnaround times. This means that asset downtime, and hence lost revenue, is minimised, but requires the availability of spare components.

Any lift from the floating substructure to a vessel needs to be heave compensated as a minimum, and ideally 3-D motion compensated.

The technology to facilitate floating-floating lifts for the largest components, such as gearboxes, is not currently available. Conducting component replacement in-situ for these items, therefore, is not an option.

There are many innovations being progressed to address this challenge. In the future, in-situ refurbishment, replacement, and repair is expected to be a cost-effective option for the largest components.

What’s in it

Guide to a Floating Offshore Wind Farm