The global transition to renewable energy sources to combat climate change is accelerating, with wind power playing a significant role. By 2050, renewable energy sources are projected to supply roughly two-thirds of the world's energy needs, a dramatic increase from 15% in 2015. Wind power, a mature low-carbon technology, contributed over 6% of global electricity demand in 2019, with an installed capacity of 651 GW projected to reach 4000 GW by 2050. This rapid expansion, however, brings the significant challenge of managing the increasing waste generated by wind turbine blades, particularly the composite materials used in their construction. The continuous growth in wind power necessitates rapid wind farm development, larger turbines, and the replacement of aging components. This surge in turbine demand leads to increased resource consumption during construction and a corresponding increase in waste generation as decommissioned units reach their end-of-life (approximately 20 years). While some turbine components, such as metals and rare earth elements, are recyclable, composite wind turbine blades pose a considerable waste management problem due to their bulkiness, complex material composition, and high recycling costs. Traditional waste management methods like landfilling and incineration are not ideal solutions. Landfilling consumes valuable land resources and fails to recover valuable materials, while incineration releases greenhouse gases and is subject to jurisdictional restrictions. Several countries, including Germany, the UK, and China, have responded by implementing regulations, financial incentives (like China's Solid Waste Law and the Guiding Opinions on Comprehensive Utilization of Bulk Solid Waste), and high gate fees (like the UK landfill tax) to encourage alternative disposal methods. Current waste handling and recycling methods encompass a range of approaches, including cement kiln co-processing, mechanical recycling, thermal recycling (pyrolysis and fluidized bed processes), and chemical recycling. These techniques vary in maturity and scalability, with processing methods impacting the quality of recycled fibers (length, strength, stiffness). The existing regulations serve as a catalyst for innovative disposal solutions, including recycling initiatives for glass fibers and resins, thus avoiding the environmental impact of primary production. China, possessing the world's largest wind power capacity (37% of the global total in 2018), faces a particularly significant waste challenge. Its ambitious goal of reaching peak emissions before 2030 and achieving carbon neutrality by 2060 necessitates the development of clean energy paths at national and provincial levels. The varied manufacturing, installation, and waste treatment profiles across China will significantly impact the spatial and temporal distribution of blade waste, an area that requires further investigation. While existing studies have provided preliminary estimations of global and national blade waste generation, they often lack resolution in their inventory models and fail to account for the impact of increasing wind turbine capacity or the dynamic cost impact of waste treatment options. Moreover, location-specific analyses of the Chinese wind turbine market at a high resolution are limited. This study aims to address these shortcomings by providing a detailed, location-specific analysis, crucial for strategic decisions regarding waste recycling plant locations, capacity planning, and related technological reserves.

Previous research has offered cursory estimations of global and national wind turbine blade waste generation, but these studies often lacked the resolution and detail necessary for effective policymaking. Liu and Barlow (2017) provided an estimate of national blade waste increase in China, but their model did not consider the impact of periodic increases in wind turbine capacity. Other studies focused on specific regions or countries, but lacked the comprehensive, high-resolution data necessary to accurately predict waste generation patterns across China's diverse geography. Existing life cycle assessment (LCA) studies often considered static impacts and limited waste treatment options (e.g., landfill, cement co-processing), neglecting the dynamic cost impact analysis and regional variability in energy provision. This study builds upon previous work by providing a more comprehensive and spatially-resolved analysis, accounting for both the dynamic changes in energy systems and the diverse waste treatment options available.

This study employs a multi-dimensional modeling approach to predict wind turbine blade waste generation, composition, and environmental impacts in China up to 2050. The methodology comprises two main stages: **1. Wind Turbine Blade Waste Prediction:** * **Data Collection:** A high-resolution database was compiled, incorporating 14 turbine capacities (150–5500 kW) based on data from 104 turbine models. This database informed the calculations of size-specific waste generation across manufacturing, operation & maintenance (O&M), and end-of-life (EOL) phases, using installed nominal capacities and turbine age. * **Scenario Development:** Three scenarios (minimum, base, and maximum) were developed for future wind power deployment in China by 2050, based on data from the International Energy Agency, Global Wind Energy Council, and China National Renewable Energy Centre. These scenarios encompassed a range of possible future capacity installations and growth patterns. * **Spatial and Temporal Distribution:** Waste generation was estimated at the national, regional, and provincial levels to understand temporal and spatial trends in waste distribution. This analysis considered the distribution of wind turbine manufacturing facilities across China, accounting for regional differences in wind energy resources, development progress, and energy policies. **2. Life Cycle Assessment (LCA) and Cost Analysis:** * **Waste Management Options:** Seven waste management options were evaluated: landfill, municipal incineration, cement kiln co-processing, mechanical recycling (with landfilling or incineration of residuals), pyrolysis recycling, fluidized bed recycling, and chemical recycling. Process models, incorporating data from pilot plant and commercial-scale operations, were developed for each option. * **Environmental Impact Assessment:** Two environmental metrics—primary energy demand (PED) and greenhouse gas (GHG) emissions—were assessed for each waste management option, considering the impact of energy mix changes at the national and provincial levels. The analysis accounted for energy recovery credits and the displacement of virgin material use with recycled materials. * **Cost Analysis:** A cost model was developed that included dismantling, handling and shredding, transportation, recycling, disposal of residuals, and credits from recyclates and energy recovery. Costs were presented in US$ for 2018, with an annual inflation rate of 2% applied. The cost model considered the different steps in the recycling process along with the value of recyclates produced. The combined waste generation prediction and LCA/cost analysis provide a comprehensive assessment of the environmental and economic implications of different wind turbine blade waste management strategies in China.

This study presents several key findings regarding wind turbine blade waste in China: * **Significant Waste Generation:** By 2050, the study projects the generation of 7.7 to 23.1 million tonnes of wind turbine blade waste in China, depending on the development scenario. The base case scenario projects 12.9 million tonnes of cumulative waste. This represents a 20-fold increase compared to the 2018 level (507 thousand tonnes). * **Dominance of End-of-Life Waste:** The proportion of waste from end-of-life (EOL) blades will significantly increase over time, surpassing manufacturing waste after 2025. This shift is attributed to the decommissioning of large numbers of wind turbines reaching the end of their operational lifespan. * **Provincial Disparities:** Significant regional disparities exist in waste generation, driven by differences in wind resource distribution, development progress, and energy policies. Certain provinces concentrate the majority of manufacturing and later EOL waste generation, creating hotspots requiring focused waste management strategies. The top five waste-generating provinces account for about half of the country's total waste. * **Environmental Impacts of Waste Management:** Recycling methods generally reduce GHG emissions compared to landfilling and incineration, with mechanical recycling achieving the greatest reduction. However, the specific environmental benefits of various treatment options change over time due to the decarbonization of China's energy grid. Pyrolysis is found to have the highest GHG emissions. * **Economic Impacts of Recycling:** Recycling options generally have lower costs than conventional disposal, except for pyrolysis. Mechanical recycling offers the lowest cost among advanced recycling technologies but is currently not fully viable in China due to the ban on the landfilling of residual materials. Fluidized bed recycling shows promise as a cost-effective and environmentally friendly approach. Chemical and pyrolysis recycling are found to be uneconomical currently. * **Potential for Material Displacement:** Using recycled glass fiber to replace virgin material in new products reduces both environmental impact and costs. High displacement factors (above 70%) for chemical recycling may achieve net GHG emission reductions. Even at low displacement factors (8%), mechanical recycling can offer net PED and GHG emission reductions.

The findings highlight the urgent need for effective and sustainable solutions for managing the escalating quantities of wind turbine blade waste in China. The current lack of viable, large-scale recycling solutions that are both environmentally sound and cost-competitive poses a significant challenge to the country's ambitious carbon neutrality goals. The study's results underscore the complexity of the issue, with no single solution being universally favorable across environmental and economic criteria. The significant variation in waste generation across provinces necessitates region-specific strategies. The interplay between waste generation patterns and the regional variations in electricity grid emission intensities further complicates waste management decisions. For example, the high coal-based electricity generation in Inner Mongolia may favor cement co-processing, while provinces with low grid emission intensity might prioritize alternative recycling technologies. The current ban on landfilling composite wastes in China also presents limitations to optimal waste management, affecting choices between economically and environmentally efficient approaches. The study's model framework and findings are not only applicable to China but can also inform policy and industry decisions in other countries grappling with similar wind turbine blade waste challenges. The spatial resolution employed in the analysis offers a valuable tool for regional planning and strategic investment in waste management infrastructure.

This study demonstrates that China will face a significant challenge in managing the growing volume of wind turbine blade waste in the coming decades. While recycling technologies offer potential solutions, none are currently commercially viable, cost-competitive, and environmentally superior across all criteria. Mechanical recycling shows the greatest promise for minimizing GHG emissions, but only when residual materials are incinerated, and the current policy prohibiting the landfilling of residual materials prevents this option from being the lowest environmental impact option. The fluidized bed recycling technique represents a potential environmentally and economically preferable approach. Policymakers and industry need to prioritize research, development, and commercialization of effective recycling solutions tailored to regional conditions and energy systems. Further research is needed to refine cost estimations and evaluate the potential of various recycling technologies on a more localized scale, and focus on closing the loop by using recycled materials in new products and applications.

The study's projections are based on specific assumptions regarding future wind power development scenarios, turbine lifespans, and recycling technologies. Uncertainties exist in predicting future wind power capacity, which could impact the accuracy of waste generation projections. The cost analysis relies on current technology costs and may not fully capture future technological advancements or changes in material prices. The study does not include offshore wind turbines, which have different waste management implications. The analysis could be further enhanced with more detailed information on regional variations in waste collection, transportation, and processing capacities.