Spatiotemporally explicit pathway and material-energy-emission nexus of offshore wind energy development in China up to the year 2060

The temporal dynamics (e.g., pace and scale) and spatial heterogeneity (e.g., turbine location and wind speed) of offshore wind power systems (WPS) are critical to maximize the carbon gains from wind energy development and avoid trade-offs among climate, resources, and waste targets. However, such a spatiotemporally refined understanding of WPS development and the associated material cycle, energy use, and greenhouse gas (GHG) emissions is largely missing from the current research. In this study, we deployed a spatialized, technology specific, stock-driven material flow analysis model to reveal the spatiotemporally explicit pathway of China's offshore WPS development and the associated material-energy-emission nexus up to the year 2060. Our results indicate a cumulative raw material requirement of 96-140 Mt, waste generation of 6.5-48 Mt, net energy payback of 2.9-12 PWh, and net reduction in GHG emissions of 2.9 - 9.7 Gt when substituting coal power until 2060 under different scenario combinations. Specifically, China's future offshore WPS development will need to address the increasing demand for critical materials (e.g., 3.8-5.2 Mt of copper and 55-140 kt of permanent magnets cumulatively until 2060) and challenges for end-of-life management (e.g., 0.3-2 Mt spent blades generated cumulatively until 2060). The spatiotemporally refined results that consider, among other key parameters, water depth and capacity factor at a 1 x 1 km resolution, revealed low values in the northern provinces (e.g., Hebei and Tianjin) and high values in the southern provinces (e.g., Guangdong and Fujian) for material flows, energy payback, and net GHG emission reduction. This combination of spatial and dynamic material flow analyses can also be applied to WPSs in other countries and regions.