Circular economy and renewable energy infrastructure such as offshore wind farms are often assumed to be developed in synergy as part of sustainable transitions. Offshore wind is among the preferred technologies for low-carbon energy. Deployment is forecast to accelerate over ten times faster than onshore wind between 2021 and 2025, while the first generation of offshore wind turbines is about to be decommissioned. However, the growing scale of offshore wind brings new sustainability challenges. Many of the challenges are circular economy-related, such as increasing resource exploitation and competition and underdeveloped end-of-use solutions for decommissioned components and materials. However, circular economy is not yet commonly and systematically applied to offshore wind. Circular economy is a whole system approach aiming to make better use of products, components and materials throughout their consecutive lifecycles. The purpose of this study is to enable the integration of a sustainable circular economy into the design, development, operation and end-of-use management of offshore wind infrastructure. This will require a holistic overview of potential circular economy strategies that apply to offshore wind, because focus on no, or a subset of, circular solutions would open the sector to the risk of unintended consequences, such as replacing carbon impacts with water pollution, and short-term private cost savings with long-term bills for taxpayers. This study starts with a systematic review of circular economy and wind literature as a basis for the coproduction of a framework to embed a sustainable circular economy throughout the lifecycle of offshore wind energy infrastructure, resulting in eighteen strategies: design for circular economy, data and information, recertification, dematerialisation, waste prevention, modularisation, maintenance and repair, reuse and repurpose, refurbish and remanufacturing, lifetime extension, repowering, decommissioning, site recovery, disassembly, recycling, energy recovery, landfill and re-mining. An initial baseline review for each strategy is included. The application and transferability of the framework to other energy sectors, such as oil and gas and onshore wind, are discussed. This article concludes with an agenda for research and innovation and actions to take by industry and government.

A Framework and Baseline for the Integration of a Sustainable Circular Economy in Offshore Wind

The recycling of glass fibre thermoset composites in general and of wind turbine blades in particular has been investigated for many years but still remains challenging. In order to provide the reader with an overview of the challenges related to the end-of-life of wind turbine blades, this review first describes the chain of processes taking place when wind turbine blades end their service life. Key elements of this value chain are presented and discussed throughout the review. These include the estimation and prediction of the volume of wind turbine blade waste, the legislation and standards framing the processes of the value chain and the technical processes transforming wind turbine blades into new valuable materials and their applications. The review highlights the need of solutions addressing the entire value chain and ends with discussing the potentials of circular economy and life cycle engineering to facilitate the implementation of sustainable solutions. To provide a holistic picture of the sustainability of these solutions, the mechanisms of social acceptance and technology perception are also discussed. • End-of-life of blade is a complex value chain made of several steps and stakeholders. • Challenges exist from the decommissioning to the reuse of blade materials. • A holistic approach is needed to implement new recycling solutions. • Economic, technical, environmental, legislation and social aspects should be considered. 

The complex end-of-life of wind turbine blades: A review of the European context

The recycling of glass fibre thermoset composites in general and of wind turbine blades in particular has been investigated for many years but still remains challenging. In order to provide the reader with an overview of the challenges related to the end-of-life of wind turbine blades, this review first describes the chain of processes taking place when wind turbine blades end their service life. Key elements of this value chain are presented and discussed throughout the review. These include the estimation and prediction of the volume of wind turbine blade waste, the legislation and standards framing the processes of the value chain and the technical processes transforming wind turbine blades into new valuable materials and their applications. The review highlights the need of solutions addressing the entire value chain and ends with discussing the potentials of circular economy and life cycle engineering to facilitate the implementation of sustainable solutions. To provide a holistic picture of the sustainability of these solutions, the mechanisms of social acceptance and technology perception are also discussed.

The inherently advantageous geographical location of East and Southeast Asia provides a great potential for the development of diverse ocean energy technologies along its densely populated coastlines. This review paper focuses on the flexibility and feasibility of emerging ocean energy technologies in this region, including wave, tidal and ocean-current energy converters, floating photovoltaics, and offshore wind-turbines. Recent research on wave energy in the region has achieved advancements such as modifying oscillating water columns to exchange higher pneumatic energy, reshaping oscillating devices to capture more kinetic energy, and improving overtopping converters to absorb more incident waves. Regarding tidal energy, the paper reviews barrage-based and stream-based turbines and investigates the efficiency improvement, flexibility enhancement and adaptation to the unique regional features. Regarding ocean current energy, research on low-velocity turbines and optimized energy storage systems has made their application in the region more competitive. In addition, offshore deployments of floating photovoltaics have recently drawn the sector's attention and are beginning to emerge in the region, although their robustness against extreme weather and wave conditions should be addressed. Furthermore, compared to other ocean technologies, offshore wind technologies have attracted the most investment in the region. Due to the fluctuation of wind-energy generation, enhancing the energy flexibility to increase its grid penetration has become a recent focus in both the academic and industrial communities. However, despite the good research and demonstrations, most of the abovementioned ocean technologies still encounter considerable techno-economic and techno-environmental challenges that limit their competitiveness in the East and Southeast Asian markets. 

State-of-the-art review of the flexibility and feasibility of emerging offshore and coastal ocean energy technologies in East and Southeast Asia

Wind turbine blade wastes and the environmental impacts in Canada

Waste generation and end-of-life (EoL) management of wind power systems (WPSs) have attracted increasing attention as the number of decommissioned wind turbines continues to increase. In this study, we have addressed this issue by applying a technology-specific, component-by-component, and stock-driven prospective dynamic material flow analysis model in the case of Guangdong, a province in South China with high wind power potential. A particular improvement in our model includes the consideration of the foundation type for offshore wind turbines and the impact of water depth. We set three scenario combinations, high, medium, and low, to reveal the scale of material stocks and flows of wind power development in Guangdong from 1989 to 2050. We found that, as the escalating development of wind power continues (particularly offshore), the total waste generation has increased from 0 tons in 1989 to 24 kilotons in 2018, and will further increase to 1,200, 740, and 490 kilotons in 2050 under the high, medium, and low, scenario combinations, respectively. This indicates a growing demand for waste disposal capacity (particularly for recycling) in the future and a necessity to consider such EoL management issue (particularly for EoL blades) and circular economy strategies (e.g., material efficiency) associated with a much-needed ambitious wind energy development plan. We also argue that relevant EoL policy for WPSs (including Extended Producer Responsibility) should be in place in advance and feasible business models should be explored with joint efforts of wind, waste, and utility industries.

Modeling waste generation and end-of-life management of wind power development in Guangdong, China until 2050

To improve the overall efficiency of the energy system, the basic structure for the energy internet of coordination and optimization of “generation-grid-load-storage” of Huangpu District, Guangzhou, China is designed, while the arrangement for the output of centralized and distributed energy module and energy storage are proposed. Taking economic benefit maximization, environmental benefit maximization and energy efficiency maximization as sub-objectives, the mathematical model of multi-objective optimal allocation and operation strategy of the energy internet is established considering supply-demand balance constraints, equipment characteristic constraints, operation mode constraints, and energy conditions constraints. The calculation results show that without considering the outsourced electricity, the balanced strategy, the economic development strategy, the environmental protection strategy, and the energy efficiency strategy are obtained by calculation, which are all superior to the traditional energy supply strategy. Moreover, considering the outsourced electricity, the proportion of outsourced electricity to total electricity is 19.8%, which is the system optimization of the energy internet under certain power demand. Compared with other strategies without outsourced electricity, the outsourced electricity strategy can have a certain emission reduction effect, but at the same time reduce the economic benefit. Furthermore, the huge difference in demand for thermal and cooling load between industrial and commercial areas results in the installed capacity of gas distributed energy stations in industrial areas being nearly twice as large as that in commercial areas. The distributed photovoltaic power generation is allocated according to the proportion of the installed roof areas of photovoltaic power generation system in residential, industrial, and commercial areas.

Multi-objective optimal allocation strategy for the energy internet in Huangpu District, Guangzhou, China

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 × 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. 

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

Study on the Economic Optimization of Energy Storage System Configuration for Wind Power Accommodation in Guangdong Province

Background and Purpose In the early 21st century, the coronavirus alone has ravaged the world three times. Public health emergencies have caused a tremendous negative impact on public health, daily life, and global economic development, for having the characteristics of complexity and great harm. To tackle these problems, a pre-generation of emergency reference plan model of public health emergencies is proposed to better deal with the outbreak and spread of public health events. Methods The method is divided into three stages. First, the modified SEIR model is used to predict the attribute values of the target case. Then, the similar case sets are extracted and filtered by calculating the similarity through the cross-efficiency evaluation method with the parallel system. Finally, the multi-stage emergency effect evaluation model is conducted so that the emergency plan with the best response effect at this stage can be made for reference. Results We collected 25 typical events of COVID-19 that occurred in 11 cities in China as historical case bases and target cases, respectively. The result of the experiment verified the feasibility and effectiveness of the proposed method. Conclusion This paper presents a new perspective on making a public health emergency plan, which could improve the decision-making accuracy and efficiency, maximize the emergency effect and save precious time for emergency response. This model can provide rapid decision supports for decision-making for public services such as government departments, centers for disease control, medical emergency centers and transport authorities, etc.

https://www.dovepress.com/getfile.php?fileID=86166

Yuntao Zhang

Papers

Modeling waste generation and end-of-life management of wind power development in Guangdong, China until 2050

Multi-objective optimal allocation strategy for the energy internet in Huangpu District, Guangzhou, China

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

Study on the Economic Optimization of Energy Storage System Configuration for Wind Power Accommodation in Guangdong Province

A Pre-Generation of Emergency Reference Plan Model of Public Health Emergencies with Case-Based Reasoning