Volume 59

Efficiency Trajectories of Offshore Wind Development in China: Insights from Multi-Level Output-Oriented DEA-Malmquist Assessment Sijia Lin, Yuan Xu

Abstract

China’s offshore wind power experienced rapid growth but a subsequent deceleration. Regaining momentum requires improving lifecycle efficiency, defined as maximizing outputs (i.e., sea-depth, distance-from-shore, electricity generation, and capacity factor) relative to inputs (i.e., turbine number, investment, subsidies, and area) under specified technical and scale conditions. This study analyzes 117 offshore wind farms, representing over 96% commissioned capacity during 2010-2023, using output-oriented Data Envelopment and Malmquist Productivity Index (DEA-Malmquist) assessment to evaluate multi-level efficiencies. At the project level, technical efficiency improved, largely due to enhanced lifecycle electricity generation and optimized spatial utilization. Nevertheless, scale inefficiency remains, reflecting the depletion of high-quality nearshore wind resources and unresolved technological challenges in deep-sea, far-offshore deployments. At the provincial level, Liaoning, Zhejiang, and Hebei exhibit lower technical and scale efficiencies compared to other coastal provinces, primarily attributed to suboptimal nearshore wind resource endowments. At the national level, efficiency evolved from fluctuations (2010-2016) to continuous growth (2017-2019) then declines (2020-2023), with strategic priorities shifting from site selection to turbine layout optimization, and ultimately to far-offshore technology adoption. These findings contribute to theoretical understandings of generation technology evolution and offer policy implications to address technical, financial, and regulatory constraints on sustainable offshore wind development.

Keywords Offshore wind farm, Data Envelopment Analysis, Malmquist Productivity Index, Life cycle assessment, Techno-economic analysis