Tracking Environmental Efficiency Across Offshore Wind Farm Stages with a Hybrid LCA–DEA Methodology

Offshore wind energy is becoming increasingly important for decarbonizing electricity systems and strengthening energy security. However, despite producing very low direct emissions during electricity generation, offshore wind farms still create environmental impacts throughout their life cycle. These impacts arise mainly from the extraction and processing of materials, component manufacturing, installation, maintenance, and end-of-life activities. Steel and copper are especially relevant during construction, while lubricants and waste oil are significant during operation and maintenance. For this reason, environmental assessment should consider not only total impacts, but also how efficiently resources are used. Combining LCA with Network Data Envelopment Analysis makes it possible to identify environmental hotspots, compare the eco-efficiency of different wind farms, and define practical improvement targets for each stage.