Navigating towards environmental sustainability assessments of offshore wind farms at the end-of-life

Offshore wind is an essential part of the future energy mix, making an accurate environmental sustainability assessment vital. However, only limited information is available of a crucial part of offshore wind’s lifecycle: its upcoming end-of-life phase. This review examines environmental sustainability assessment studies of bottom-fixed offshore wind farms, particularly focusing on this end-of-life phase. From an initial pool of 328 publications covering the environmental sustainability of offshore wind farms, only 17 included this end-of-life phase in a sufficient way to allow for in-depth analysis, underscoring a notable gap in the literature. Resulting from this in-depth analysis, a significant gap in temporal detailing and access to primary data was found. Moreover, few studies were found truly transparent and repeatable, with many lacking clear demarcations of their lifecycle stages and a pressing reliance on non-representative sources or process data. While all studies encompass some carbon footprint analogue, broader environmental impacts are less consistently addressed. Detailed technical and decommissioning descriptions remain scarce, leading to assumptions based on limited primary sources. This review underscores the need for assessments that incorporate detailed temporal scopes, end-of-life and decommissioning processes as well as learning effects to account for technological and material advancements. The study highlights the importance of integrating circular economy principles and metrics in providing a comprehensive sustainability analysis and calls for greater transparency and stakeholder engagement to effectively address the complexities and evolving policy frameworks within the offshore wind farm lifecycle.