Comparison of Operation and Maintenance of Floating 14 MW Turbines and Twin 10 MW Turbines

Nadezda Avanessova*, James Land, Alistair Lee, Iraklis Lazakis, R. Camilla Thomson

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract / Description of output

Turbine ratings in the past decade have grown unexpectedly fast. In 2021, Siemens Gamesa and GE revealed their new 14 MW turbine models, and it is predicted that this is not yet the rating limit that turbines can reach. Increased turbine ratings can also be achieved by putting two turbines on a single foundation. This study analyzes how operation and maintenance (O&M) would differ if a floating wind farm had twin 10 MW turbines installed on each substructure, instead of a single 14 MW turbine. This study demonstrates how the strategic O&M simulation tool compass can be used to perform this comparison. Assumptions regarding the O&M of twin turbines were estimated with the major floating twin turbine developer Hexicon AB. This study analyzed four cases—a case with 35 twin 10 MW turbines, and three cases with 50 single 14 MW turbines—to understand the potential effect of increased consumable costs, spare part lead times, and maintenance durations. All cases had the same wind farm capacity of 700 MW. The results show that O&M for cases with single turbines is at least 4.5% more expensive than the case with twin turbines. The case with twin turbines also resulted in a higher availability than any other case. Additionally, results showed that operational expenditure (OPEX) for the cases with single turbines is at least 6.0% higher in scenarios with single turbines than in the twin turbine scenario. The biggest cost contributors to the difference between scenarios were craft costs, particularly cable laying vessels and tugs. Due to the higher number of cables required for the scenario with single turbines, there is more frequent mobilization of cable vessels for cable repairs.
Original languageEnglish
Title of host publicationASME Open Journal of Engineering
Subtitle of host publication4th International Offshore Wind Technical Conference
Place of PublicationBoston, MA
PublisherThe American Society of Mechanical Engineers(ASME)
Number of pages7
Publication statusE-pub ahead of print - 18 May 2023
EventASME 4th International Offshore Wind Technical Conference (IOWTC2022) - Boston, United States
Duration: 7 Dec 20228 Dec 2022
Conference number: 4


ConferenceASME 4th International Offshore Wind Technical Conference (IOWTC2022)
Abbreviated titleIOWTC2022
Country/TerritoryUnited States
Internet address


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