Estimating the major replacement rates in next-generation offshore wind turbines using structured expert elicitation.

Abstract

With offshore wind turbines continuing to increase in size and move further offshore and into harsher environments, the complexity of carrying out the major replacement of large components is expected to pose a significant challenge for future offshore wind farms. However, the rate of major replacement operations that will be required in these next generation offshore wind turbines is currently unknown. Using a structured expert elicitation method, based on the Classical Model and implemented using EFSA guidance for the practical application of structured expert elicitation, major replacement rates of large components (generator, gearbox, and rotor) were systematically estimated for four next generation offshore wind turbine configurations, based on the knowledge of six wind energy experts. The results presented in this paper are based on an equal-weighting aggregation approach. The major replacement rate values found using this approach are presented and compared between different turbine configurations. Based on these results, it is expected that a larger number of major replacement operations are more likely to be required in medium-speed turbine configurations, in comparison to direct- drive, and in floating turbines, in comparison to fixed-foundation turbines.

Operational Expenditure Modelling of the X-Rotor Offshore Wind turbine concept: Sensitivity of Key Modelling Assumptions

“…Perhaps the most suitable candidate methodology to do so is expert elicitation. Jenkins et al [12] and Zitrou et al [13] provide examples of the application of expert elicitation methods to O&M modelling in the wind industry.…”

Economic feasibility study for continued operation of German offshore wind farms

“…Any inputs have been discussed with several OWF operators for verification and have been adapted where necessary. For this purpose, structured expert elicitation similar as in [13] was applied. Approximately ten stakeholder interviews with different entities were conducted using a previously defined questionnaire with around 50 questions.…”

Operations and Maintenance Cost Comparison Between 15 MW Direct-Drive and Medium-Speed Offshore Wind Turbines

“…Both fixed-bottom and floating turbine concepts are considered. While the cited conference paper provides combined replacement rates for these components (Jenkins et al (2022a)) , the breakdown of replacement rates by component is presented in Jenkins (2022) PhD thesis. The results of that analysis is shown in Figure 4.…”

“…Jenkins et al (2022b), provide an estimate for availability and O&M costs from component replacements for the two configurations presented in Figure 1 for next generation (15 MW) turbines. Their replacement rates were based on structured expert elicitation, which is detailed further in Jenkins et al (2022a). In contrast to the results of Carroll et al (2017), their results showed that medium-speed turbines had lower O&M costs for major replacements than direct-drive machines.…”

“…Coinciding with this shift in the market towards direct drive turbines is a shift towards higher power ratings (Jenkins et al (2022a)). This is a theme investigated by Turnbull et al (2022).…”