Weather downtime support for floating offshore wind O&M cost assessment

Using Weather Downtime Express to test scenarios for floating offshore wind operation and maintenance repairs

As the world decarbonises to meet emissions reduction targets, floating offshore wind is seen to have huge potential to contribute to the energy mix.

The Offshore Wind Innovation Hub (OWIH) undertook a study into potential operation and maintenance (O&M) costs for floating wind, as part of a report looking at options for repairs estimated at 23% of annual O&M costs.

The study compared the costs of employing either an offsite (tow to port) or onsite (fix in-situ) for various scenarios.

To understand the impact of weather on operational programme (task list), for each option OWIH used ABPmer’s weather downtime calculator, Weather Downtime Express (WDTX)

WDTX used the task lists and associated working limits to simulate the completion of all tasks, in sequence, over a wide range of historical conditions at the chosen sites.

The use of WDTX helped OWIH reach key conclusions in their report.
For example:

  • Significant weather restrictions, combined with completion time, mean that component replacement at height incurs the greatest weather downtime and highest cost of all tasks analysed
  • Even in harsh weather conditions, tow-to-port repair of semi-submersibles is always the lowest cost option for major repairs