Long-term extreme response of an offshore turbine: How accurate are contour-based estimates?

Andreas F. Haselsteiner*, Malte Frieling, Ed Mackay, Aljoscha Sander, Klaus-Dieter Thoben

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

1 Citaat (Scopus)
52 Downloads (Pure)


According to design standards, offshore wind turbines need to withstand environmental loads with a return period of 50 years. This work compares the extreme response along the 50-year environmental contour with the true 50-year wind turbine response. It was found that the environmental contour method that is currently described in the IEC design standard for offshore wind turbines can strongly under-predict the 50-year return value of response variables whose annual maxima typically occur during power production. The bias in the contour-based estimate of the 50-year response can be attributed to three sources: (1) the method used to construct the contour; (2) neglecting serial correlation in environmental conditions; and (3) neglecting the short-term variability in the response. In our analysis the 50-year maximum mudline overturning moment was underestimated by 4–8% by the contour-based approach that is currently recommended, whereas the bending moment at 10 m water depth was underestimated by 25–28%. This underestimation was mainly due to ignoring the short-term variability in the response. The bias associated with contour construction, an effect much discussed in recent publications, was of much smaller magnitude.
Originele taal-2English
Pagina's (van-tot)945-965
Aantal pagina's21
TijdschriftRenewable Energy
Vroegere onlinedatum27-sep-2021
StatusPublished - jan-2022

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