Abstract

Wind turbine systems are designed to produce renewable energy and minimize fossil fuel dependency, thus bringing operational carbon emissions to the minimum. However, their sustainability goes beyond power generation as they also integrate materials such as steel, concrete, and non-recyclable composites. Therefore, circular economy concepts focusing on the use of recyclable materials, efficient manufacturing processes and innovative end-of-life solutions are important to ensure sustainability. Thus, a circular economy point of view on the state-of-the-art of such systems is of interest. However, despite abundant research conducted over the years, there is a lack of comprehensive quantitative studies relating circular economy strategies and components used in wind turbines. To fill this gap, this study presents a systematic literature mapping using an automated text analysis tool developed by the authors. The process quantifies the frequency (appearances per 10000 words) and correlation (Pearson) of circular economy indicators, environmental impacts, materials and wind turbine components, complemented by manual review of 540 research articles. The findings show that recycling and blades are the most quoted concepts with 9.7 and 8.7 appearances per 10000 words respectively, and significantly higher correlation than other indicators. Higher-tier circular economy strategies, such as reuse and reduce are less discussed which have 2.7 and 1.9 appearances per 10000 words respectively. Results also show a clear gap between current research focus and comprehensive circular economy implementation. In order to fill this gap, this study emphasizes prioritising higher-tiered economy strategies, and the necessity of better integrating design-for-disassembly, secondary material markets, policy support, social aspects and life cycle assessment approaches.