{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,13]],"date-time":"2026-06-13T15:22:05Z","timestamp":1781364125239,"version":"3.54.1"},"reference-count":35,"publisher":"Copernicus GmbH","issue":"6","license":[{"start":{"date-parts":[[2024,6,19]],"date-time":"2024-06-19T00:00:00Z","timestamp":1718755200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000266","name":"Engineering and Physical Sciences Research Council","doi-asserted-by":"publisher","award":["EP\/S023801"],"award-info":[{"award-number":["EP\/S023801"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000266","name":"Engineering and Physical Sciences Research Council","doi-asserted-by":"publisher","award":["EP\/T031549\/1"],"award-info":[{"award-number":["EP\/T031549\/1"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Wind Energ. Sci."],"abstract":"<jats:p>Abstract. Determining offshore wind energy operational expenditures relies on acquiring reliability data, particularly as turbine power ratings increase. The uncertainty surrounding operational costs and optimal drivetrain configurations for larger turbines persists. While previous research has addressed reliability data for 3\u2009MW offshore wind turbines, this study reviews and collates updated failure data for 15\u2009MW turbines, comparing direct-drive and medium-speed configurations. It employs an operation and maintenance (O&amp;amp;M) modelling tool to calculate total operational costs. The study concurs with existing literature, showing that direct-drive turbines have lower operational costs than medium-speed turbines in three case studies. However, the cost and availability differences between configurations are smaller than previously suggested. For 15\u2009MW turbines, the analysis reveals that the cost disparity between direct-drive and medium-speed turbines is significantly smaller than for smaller-rated turbines, with percentages of 1.59\u2009%, 1.58\u2009%, and 5.78\u2009% for the three ScotWind sites selected. Previously, the absolute percentage difference in cost between direct-drive and medium-speed turbines was estimated to be 29.79\u2009%. Sensitivity analyses explore the influence of three factors \u2013 failure rates, accessibility limits, and major replacement times \u2013 on total operational costs. These analyses demonstrate that medium-speed configurations exhibit more significant cost fluctuations, and the cost gap between configurations is reduced if failure rates are lowered at the same rate for each configuration, accessibility increases, or the major replacement time is reduced for the larger wind turbine components.<\/jats:p>","DOI":"10.5194\/wes-9-1345-2024","type":"journal-article","created":{"date-parts":[[2024,6,19]],"date-time":"2024-06-19T02:11:56Z","timestamp":1718763116000},"page":"1345-1362","source":"Crossref","is-referenced-by-count":14,"title":["Operation and maintenance cost comparison between 15\u2009MW direct-drive and medium-speed offshore wind turbines"],"prefix":"10.5194","volume":"9","author":[{"given":"Orla","family":"Donnelly","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fraser","family":"Anderson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James","family":"Carroll","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"3145","published-online":{"date-parts":[[2024,6,19]]},"reference":[{"key":"ref1","unstructured":"Anderson, F.: Operational Data Mining for Offshore Wind Farm Maintenance, PhD thesis, University of Edinburgh, https:\/\/doi.org\/10.7488\/era\/4357, 2023.\u2002a, b, c, d"},{"key":"ref2","unstructured":"Carroll, J.: Cost of energy modelling and reduction opportunities for offshore wind turbines, PhD thesis, University of Strathclyde, https:\/\/doi.org\/10.48730\/akxk-rq05, 2016\u2002a, b, c, d, e, f, g"},{"key":"ref3","doi-asserted-by":"crossref","unstructured":"Carroll, J., McDonald, A., and McMillan, D.: Failure rate, repair time and unscheduled O&amp;amp;M cost analysis of offshore wind turbines, Wind Energy, 19, 1107\u20131119, 2016.\u2002a, b, c, d, e, f, g, h, i, j, k","DOI":"10.1002\/we.1887"},{"key":"ref4","doi-asserted-by":"crossref","unstructured":"Carroll, J., McDonald, A., Dinwoodie, I., McMillan, D., Revie, M., and Lazakis, I.: Availability, operation and maintenance costs of offshore wind turbines with different drive train configurations, Wind Energy, 20, 361\u2013378, https:\/\/doi.org\/10.1002\/we.2011, 2017.\u2002a, b, c, d, e, f, g, h, i","DOI":"10.1002\/we.2011"},{"key":"ref5","unstructured":"Catapult, O. 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