Wind turbine blade waste in 2050

Co-processing of end-of-life wind turbine blades in portland cement production

The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process.

Effects of temperature and moisture fluctuations for suitable use of raw-crushed wind-turbine blade in concrete

Raw-crushed wind-turbine blade (RCWTB), a waste from the recycling of wind-turbine blades, is used as a raw material in concrete in this research. It contains not only fiberglass-composite fibers that bridge the cementitious matrix but also polyurethane and balsa-wood particles. Therefore, concrete containing RCWTB can be notably affected by moisture and temperature fluctuations and by exposure to high temperatures. In this research, the performance of five concrete mixes with 0.0%, 1.5%, 3.0%, 4.5%, and 6.0% RCWTB, respectively, is studied under moist/dry, alternating-sign-temperature-shock, and high-temperature-shock tests. Two damage mechanisms of RCWTB within concrete were found through these tests: on the one hand, micro-cracking of the cementitious matrix, which was verified by microscopic analyses and was dependent on concrete porosity; on the other, damage and degradation of the RCWTB components, as the polyurethane melted, and the balsa-wood particles burned. Both phenomena led to larger remaining-strain levels and reduced concrete compressive strength by up to 25% under temperature and humidity variations, although the bridging effect of the fiberglass-composite fibers was effective when adding RCWTB amounts higher than 3.0%. The compressive-strength loss after the high-temperature-shock test increased with the RCWTB content, reaching maximum values of 8% after an exposure time of 7 days. Statistical analyses revealed that effect of the RCA amount in the concrete was conditioned by the exposure times in all the tests. The accurate definition of those times is therefore key to set an RCWTB content in concrete that ensures its suitable behavior under the environmental conditions analyzed.

Possibility of Using Wind Turbine Waste in Particleboard Manufacturing

Recent reports indicate that the development of electricity generation using wind turbines will continue to grow. Despite the long service life of wind turbine blades, their technological life comes to an end at a certain point. Currently, there is no industrial method for recycling them, and the proposed solutions need to consider a complete and comprehensive approach to this material. In many countries, these blades are stored in special landfills and await proposals for rational recycling. It has been proposed that this recyclable yet still troublesome raw material be used in building sheathing boards. Sheathing boards used in the construction industry have a relatively long lifecycle. Three types of polymer chips and two resins, i.e., PF and MUF, were used in the study. The boards' quality was assessed per the standards specified for particle boards. The resulting boards were characterized by strengths above 20 N/mm2 and an elastic modulus close to 4000 N/mm2. Slightly better results were obtained with the MUF resin.

Evaporation-Driven Energy Generation Using an Electrospun Polyacrylonitrile Nanofiber Mat with Different Support Substrates

Water evaporation-driven energy harvesting is an emerging mechanism for contributing to green energy production with low cost. Herein, we developed polyacrylonitrile (PAN) nanofiber-based evaporation-driven electricity generators (PEEGs) to confirm the feasibility of utilizing electrospun PAN nanofiber mats in an evaporation-driven energy harvesting system. However, PAN nanofiber mats require a support substrate to enhance its durability and stability when it is applied to an evaporation-driven energy generator, which could have additional effects on generation performance. Accordingly, various support substrates, including fiberglass, copper, stainless mesh, and fabric screen, were applied to PEEGs and examined to understand their potential impacts on electrical generation outputs. As a result, the PAN nanofiber mats were successfully converted to a hydrophilic material for an evaporation-driven generator by dip-coating them in nanocarbon black (NCB) solution. Furthermore, specific electrokinetic performance trends were investigated and the peak electricity outputs of Voc were recorded to be 150.8, 6.5, 2.4, and 215.9 mV, and Isc outputs were recorded to be 143.8, 60.5, 103.8, and 121.4 μA, from PEEGs with fiberglass, copper, stainless mesh, and fabric screen substrates, respectively. Therefore, the implications of this study would provide further perspectives on the developing evaporation-induced electricity devices based on nanofiber materials.

Fluorescent carbon dots synthesized by waste wind turbine blade for photocatalytic degradation

Developing novel waste recycling strategies has become a feasible solution to overcome environmental pollution. In this work, a method of using waste wind turbine blade (WTB) as a carbon source to synthesize blue fluorescent carbon dots (B-CDs) by hydrothermal treatment is proposed. B-CDs are spherical and have an average particle size of 5.2 nm. The surface is rich in C-O, C=O, -CH3 , and N-H bond functional groups, containing five elements: C, O, N, Si, and Ca. The optimal emission wavelength of B-CDs is 463 nm, corresponding to an excitation wavelength of 380 nm. Notably, a relatively high quantum yield of 29.9% and a utilization rate of 40% were obtained. In addition, B-CDs can serve as a photocatalyst to degrade methylene blue dye, with a degradation efficiency of 64% under 40-min irradiation conditions. The presence of holes has a significant influence on the degradation process.

A New Concept of Sustainable Wind Turbine Blades: Bio-Inspired Design with Engineered Adhesives

In this paper, a new concept of extra-durable and sustainable wind turbine blades is presented. The two critical materials science challenges of the development of wind energy now are the necessity to prevent the degradation of wind turbine blades for several decades, and, on the other side, to provide a solution for the recyclability and sustainability of blades. In preliminary studies by DTU Wind, it was demonstrated that practically all typical wind turbine blade degradation mechanisms (e.g., coating detachment, buckling, spar cap/shell adhesive joint degradation, trailing edge failure, etc.) have their roots in interface degradation. The concept presented in this work includes the development of bio-inspired dual-mechanism-based interface adhesives (combining mechanical interlocking of fibers and chemical adhesion), which ensures, on the one side, extra-strong attachment during the operation time, and on the other side, possible adhesive joint separation for re-use of the blade parts. The general approach and physical mechanisms of adhesive strengthening and separation are described.

Circular economy performance and carbon footprint of wind turbine blade waste management alternatives

It is estimated that 570 Mt of blade waste, whose management is complex and expensive, will be generated by 2030 in the European Union alone. Accordingly, alternative blade waste management techniques are being investigated to optimize material recovery. This study evaluates the correlation between the circular economy performance and the carbon footprint of seven end-of-life management solutions for wind turbine blades: repurposing, grinding, solvolysis, pyrolysis, co-processing in cement kilns, incineration with energy recovery and landfilling. The circular economy performance is analyzed through the calculation of the product circularity indicator, while the carbon footprint is determined through life cycle assessment, using the global warming indicator and considering the management of three blades from cradle-to-gate as functional unit. As the performance of solvolysis and pyrolysis recycling is expected to change in the future, a sensitivity analysis is also carried out to evaluate the variability of the results by changing their process efficiency and the quality of the recovered materials. The results indicate that blade recycling through solvolysis is the most circular (0.47-0.77) and low-carbon (225-503 CO₂ eq.) solution overall. Blade repurposing, grinding and cement co-processing have a similar circularity (0.52-0.55) and a global warming impact ranging from 499 t CO₂ eq. to 615 t CO₂ eq. Although the circularity of pyrolysis is 59% (0.35) to 118% (0.48) greater than the circularity of incineration and landfilling (0.22), its carbon footprint can range from 566 t CO₂ eq. to 744 t CO₂ eq, which could be up to 19% higher than the carbon footprint of these linear EoL management alternatives (623 t CO₂). Based on these findings, proposals for sustainable industrial innovation and methodological recommendations for the development of integrated circularity and sustainability studies are proposed.

Study on the Utilization of Waste Thermoset Glass Fiber-Reinforced Polymer in Normal Strength Concrete and Controlled Low Strength Material

Thermoset glass fiber-reinforced polymers (GFRP) have been widely used in manufacturing and construction for nearly half a century, but the large amount of waste produced by this material is difficult to dispose of. In an effort to address this issue, this research investigates the reuse of thermoset GFRP waste in normal strength concrete (NSC) and controlled low-strength materials (CLSM). The mechanical performance and workability of the resulting concrete were also evaluated. To prepare the concrete specimens, the thermoset GFRP waste was first pulverized into granular pieces, which were then mixed with cement, fly ash, and water to form cylindrical concrete specimens. The results showed that when the proportion of thermoset GFRP waste aggregate in the concrete increased, the compressive strengths of NSC and CLSM would decrease. However, when incorporating 5% GFRP waste into CLSM, the compressive strength was 7% higher than concrete without GFRP. However, the workability of CLSM could be improved to meet engineering standards by adding an appropriate amount of superplasticizer. This finding suggests that the use of various combinations of proportions in the mixture during production could allow for the production of CLSM with different compressive strength needs. In addition, the use of recycled thermoset GFRP waste as a new aggregate replacement for traditional aggregates in CLSM was found to be a more sustainable alternative to the current CLSM combinations used in the market.

Catalytic disconnection of C-O bonds in epoxy resins and composites

Fibre-reinforced epoxy composites are well established in regard to load-bearing applications in the aerospace, automotive and wind power industries, owing to their light weight and high durability. These composites are based on thermoset resins embedding glass or carbon fibres¹. In lieu of viable recycling strategies, end-of-use composite-based structures such as wind turbine blades are commonly landfilled^1-4. Because of the negative environmental impact of plastic waste^5,6, the need for circular economies of plastics has become more pressing^7,8. However, recycling thermoset plastics is no trivial matter^1-4. Here we report a transition-metal-catalysed protocol for recovery of the polymer building block bisphenol A and intact fibres from epoxy composites. A Ru-catalysed, dehydrogenation/bond, cleavage/reduction cascade disconnects the C(alkyl)-O bonds of the most common linkages of the polymer. We showcase the application of this methodology to relevant unmodified amine-cured epoxy resins as well as commercial composites, including the shell of a wind turbine blade. Our results demonstrate that chemical recycling approaches for thermoset epoxy resins and composites are achievable.

Recycling of Wind Turbine Blades into Microfiber Using Plasma Technology

As the industry develops and energy demand increases, wind turbines are increasingly being used to generate electricity, resulting in an increasing number of obsolete turbine blades that need to be properly recycled or used as a secondary raw material in other industries. The authors of this work propose an innovative technology not yet studied in the literature, where the wind turbine blades are mechanically shredded and micrometric fibers are formed from the obtained powder using plasma technologies. As shown by SEM and EDS studies, the powder is composed of irregularly shaped microgranules and the carbon content in the obtained fiber is lower by up to seven times compared with the original powder. Meanwhile, the chromatographic studies show that no hazardous to the environment gases are formed during the fiber production. It is worth mentioning that this fiber formation technology can be one of the additional methods for recycling wind turbine blades, and the obtained fiber can be used as a secondary raw material in the production of catalysts, construction materials, etc.

Investigation of the best possible methods for wind turbine blade waste management by using GIS and FAHP: Turkey case

The aim of this study is to present the status and projections of wind turbine blade retirement in Turkey; to investigate the number of retiring WT blades in the regional, manufacturer, and material aspects; and to discuss the management methods for retired WT blades. To determine the best possible wind turbine blade waste management methods for Turkey, a combined application of Geographical Information Systems (GIS) and the Fuzzy Analytical Hierarchy Process (FAHP) is used in this study. It is found that around nine thousand WT blades will become waste between 2020 and 2039 in Turkey, corresponding to around 80,500 tons of waste. On average, 52,325 tons of glass/carbon and 28,175 tons of polymers will be accumulated between 2020 and 2039 from wind turbine blades. More than half of the WT blade waste will come from two WT manufacturers, namely, Enercon and Nordex. Aegean and Marmara regions will provide 74% of the blade waste, where 33% of them will be 2 MW and 2.5 MW sizes of WT blades. Furthermore, a case study is applied to Izmir city to demonstrate the results of FAHP for finding the best available method to dispose of WT blades. The results show that using blade waste as filling material is the best alternative, while waste-to-energy is the last favorable option for blade waste management. Finally, sensitivity analyses are applied to demonstrate the robustness of the results for the inclusion of new alternatives and the bias of experts' judgments.

Zero-Waste Recycling of Fiber/Epoxy from Scrap Wind Turbine Blades for Effective Resource Utilization

The number of scrap wind turbines is expanding globally as the wind power industry develops rapidly. Zero-waste recycling of scrap wind turbine blades (WTB) is the key for wind power firms to achieve green and sustainable development on the premise of satisfying environmental protection criteria. In this work, the pyrolysis of fiber/epoxy composites obtained from scrap WTB in oxidizing inert atmospheres was investigated. Various characterization methods were employed to characterize the microstructure and chemical characteristics of the heat-treated fiber/epoxy and to reveal the pyrolysis mechanism. In addition, the heat-treated fibers/epoxy were used as reinforcing agents to investigate their impact on the elastic deformation of butadiene styrene rubber-based flexible composites, and the reinforcing mechanism was revealed. The results revealed that the constituents of fiber/epoxy composites were mostly fiberglass (SiO₂, CaCO₃) and cured epoxy resin, with covalent bonding being the interaction between the fiberglass and epoxy resin. The total weight of the epoxy resin in the fiber/epoxy composites was 22%, and the 11% weight loss was achieved at around 350 °C, regardless of the presence of oxygen; however, the features of heat-treated fibers/epoxy were associated with the pyrolysis atmosphere at a higher temperature. The pyrolysis products in inert atmospheres, with water contact angles of 58.8°, can considerably improve the tensile properties of flexible composites at the elastic stage. Furthermore, the flexible composite granules were prepared to plug large channels in sand-filled pipes, and the plugging rate had the potential to reach 81.1% with an injection volume of 5.0 PV. The plugging performance was essentially unaffected by water salinity, owing to the high stability of flexible composite granules in mineralized water. The findings of this study present a realistic route to the industrial application of fiber/epoxy, as well as a novel approach for encouraging the efficient use of scrap wind turbines on a large scale.

A mini-review of end-of-life management of wind turbines: Current practices and closing the circular economy gap

Renewable energy generation and increased electrification are pivotal to reducing greenhouse gas emissions and mitigating climate change. Consequently, global deployment of wind turbines has soared, and the trend is expected to continue. Installed turbines have only recently started reaching the end of their design lives, and waste volumes are projected to escalate rapidly. Approximately 94% of a wind turbine (by mass) is recyclable, but the waste polymer composite blades are most commonly landfilled. This mini-review aims to review current end-of-life (EoL) management practices in the large-scale wind industry for countries with established EoL standards as well as those with less mature regulations. Data on current EoL management practices, initiatives and regulations in industry was sourced primarily from literature reviews and publicly available internet information. Additional insights and perspectives were gained from WindEurope's EoL Issues and Strategies 2020 seminar and through communication with select individuals from various sectors such as wind energy development and operations, government, industry associations, academia and research organizations. The results show that the decision on EoL options is dictated by the remaining useful life (RUL) of the wind turbines, prevailing policies and electricity prices. The contribution of this article is, firstly, identifying a number of key technical, economic and regulatory questions that must be asked before deciding on the most appropriate EoL option. Secondly, the article identifies factors that impede current EoL management efforts to close the circular economy gap and those that can support sustainable technology deployment. Finally, the article considers the way that countries with a young fleet of wind farms may learn from more experienced nations. There are few proven business cases, and barriers to the profitability and effectiveness of EoL strategies include uncertainty about the assets' RUL, collection logistics, the size of wind farm operation margins, low waste feedstock and limited markets for recycled products. Designing for circularity, stakeholder collaboration, circular business models and technology-specific regulations can improve EoL sustainability. The research found that wind turbine EoL management is dynamic and complex and needs to consider multiple, often conflicting factors. However, it is necessary and has immense environmental, technical and economic potential as the industry matures and business cases are proven.

Regional representation of wind stakeholders' end-of-life behaviors and their impact on wind blade circularity

The growing number of end-of-life (EOL) wind blades could further strain US landfills or be a valuable composite materials source, depending on stakeholders' behaviors. Technical solutions based on circular economy (CE) principles have been proposed but are not guaranteed to solve the issue of EOL management. Transitioning to CE implies changing how business models, supply chains, and behaviors deal with products and waste. A spatially resolved agent-based modeling combined with a machine-learning metamodel shows that including behavioral factors is crucial to designing effective policies. Logistical barriers and transportation costs significantly affect the results: lowering blade shredding costs by a third before transportation makes EOL blades a source of valuable materials, decreasing the 2050 cumulative landfill rate below 50%. In another scenario, parameter settings simulating policy interventions aiming at boosting early adoption incites new social norms favorable to recycling, lowering the cumulative landfill rate below 10%.

Recovery and Use of Recycled Carbon Fibers from Composites Based on Phenol-Formaldehyde Resins

The technical feasibility of the recycling of specific polymeric composite materials was evaluated. Two types of carbon composites, both with phenol-formaldehyde resin but with different reinforcement, were studied. It was discovered that the solvolysis with the oxidizing agents used in an acidic environment allowed for the achievement of a high-efficiency fiber extraction. The extracted secondary carbon fibers had a high degree of purity (95–99.5% of resin was removed). Fiber thickness slightly decreased during the process (on average, by 20%). The use of chopped secondary fibers (3–9 mm fiber length) for concrete reinforcement produced a positive effect. Hence, the compressive and bending strength of the concrete blocks were accordingly 1.5% and 16% higher in comparison with the control sample. The use of secondary carbon fabric for the production of composite materials a good result: the effective tensile strength of CFRP samples reinforced with recovered fabric is only lower by 4.5% in comparison with virgin fabric.

Onshore Wind Farm Development: Technologies and Layouts

Significantly growing wind energy is being contemplated as one of the main avenues to reduce carbon footprints and decrease global risks associated with climate change. However, obtaining a comprehensive perspective on wind energy considering the many diverse factors that impact its development and growth is challenging. A significant factor in the evolution of wind energy is technological advancement and most previous reviews have focused on this topic. However, wind energy is influenced by a host of other factors, such as financial viability, environmental concerns, government incentives, and the impact of wind on the ecosystem. This review aims to fill a gap, providing a comprehensive review on the diverse factors impacting wind energy development and providing readers with a holistic panoramic, furnishing a clearer perspective on its future growth. Data for wind energy was evaluated by applying pivot data analytics and geographic information systems. The factors impacting wind energy growth and development are reviewed, providing an overview of how these factors have impacted wind maturity. The future of wind energy development is assessed considering its social acceptance, financial viability, government incentives, and the minimization of the unintended potential negative impacts of this technology. The review is able to conclude that wind energy may continue growing all over the world as long as all the factors critical to its development are addressed. Wind power growth will be supported by stakeholders’ holistic considerations of all factors impacting this industry, as evaluated in this review.

Experimental Characterizations of Hybrid Natural Fiber-Reinforced Composite for Wind Turbine Blades

Performances of hybrid Natural Fiber-Reinforced Composites (NFRCs) from E-glass, Nacha (Hibiscus macranthus Hochst. Ex-A. Rich.), and Sisal (Agave sisalana) fibers are investigated for wind turbine blades applications. The process of composite manufacturing was getting started with harvesting and extracting the fibers from undesired constituents. To improve the interfacial interaction between fibers, it was further treated with 5% of NaOH and remnants removal. The experiment was performed based on the Taguchi method, specifically with L₁₆ orthogonal array. Four levels of a natural fiber weight ratio (i.e. 5%, 10%, 15 %, and 20%) were considered during the composite preparations process while the weight of glass fiber was maintained at 5% and 10%. The composites are manufactured using the hand lay-up method, and the test specimens are as per American Society for Testing and Materials (ASTM) standards. Then, tensile, compressive, and flexural tests were carried out using a universal testing machine (UTM). Analysis of variance (ANOVA) was employed to determine the factors which affect the experimental responses. Hence, in the main effect, it was confirmed that Nacha fiber (%wt of N) significantly contributes to tensile, compressive, and flexural strength at a 95% level of confidence. Furthermore, the optimal fiber compositions of composites are determined based on a higher signal-to-noise ratio (S/N) for the corresponding strengths.

Recycling of Reinforced Glass Fibers Waste: Current Status

In this paper, a review of the current status and future perspectives for reinforced glass fiber waste is undertaken, as well as an evaluation of the management hierarchy for these end-of-life materials. Waste levels are expected to increase in the coming years, but an improvement of collection routes is still necessary. The recycling processes for these materials are presented. The associated advantages and disadvantages, as well as the corresponding mechanical characteristics, are described. Although mechanical shredding is currently the most used process, there is a potential for thermal processes to be more competitive than others due to the fiber quality after the recycling process. However, the energy requirements of each of the processes are not yet well explained, which compromises the determination of the economic value of the recycled fibers when included in other products, as well as the process feasibility. Nevertheless, the work of some authors that successfully integrated recycled glass fibers into other elements with increased mechanical properties is evaluated. Future recommendations for the recycling of glass fiber and its commercialization are made.

Post COVID-19 ENERGY sustainability and carbon emissions neutrality

This review covers the recent advancements in selected emerging energy sectors, emphasising carbon emission neutrality and energy sustainability in the post-COVID-19 era. It benefited from the latest development reported in the Virtual Special Issue of ENERGY dedicated to the 6th International Conference on Low Carbon Asia and Beyond (ICLCA'20) and the 4th Sustainable Process Integration Laboratory Scientific Conference (SPIL'20). As nations bind together to tackle global climate change, one of the urgent needs is the energy sector's transition from fossil-fuel reliant to a more sustainable carbon-free solution. Recent progress shows that advancement in energy efficiency modelling of components and energy systems has greatly facilitated the development of more complex and efficient energy systems. The scope of energy system modelling can be based on temporal, spatial and technical resolutions. The emergence of novel materials such as MXene, metal-organic framework and flexible phase change materials have shown promising energy conversion efficiency. The integration of the internet of things (IoT) with an energy storage system and renewable energy supplies has led to the development of a smart energy system that effectively connects the power producer and end-users, thereby allowing more efficient management of energy flow and consumption. The future smart energy system has been redefined to include all energy sectors via a cross-sectoral integration approach, paving the way for the greater utilization of renewable energy. This review highlights that energy system efficiency and sustainability can be improved via innovations in smart energy systems, novel energy materials and low carbon technologies. Their impacts on the environment, resource availability and social well-being need to be holistically considered and supported by diverse solutions, in alignment with the sustainable development goal of Affordable and Clean Energy (SDG 7) and other related SDGs (1, 8, 9, 11,13,15 and 17), as put forth by the United Nations.

Comment on Seibert, M.K.; Rees, W.E. Through the Eye of a Needle: An Eco-Heterodox Perspective on the Renewable Energy Transition. Energies 2021, 14, 4508

This paper exposes the many flaws in the article “Through the Eye of a Needle: An Eco-heterodox Perspective on the Renewable Energy Transition, authored by Siebert and Rees and recently published in Energies as a Review. Our intention in submitting this critique is to expose and rectify the original article’s non-scientific approach to the review process that includes selective (and hence biased) screening of the literature focusing on the challenges related to renewable energies, without discussing any of the well-documented solutions. In so doing, we also provide a rigorous refutation of several statements made by a Seibert–Rees paper, which often appear to be unsubstantiated personal opinions and not based on a balanced review of the available literature.

Recycling of Mechanically Ground Wind Turbine Blades as Filler in Geopolymer Composite

This paper concerns the recycling of waste material from wind turbine blades. The aim of the research was to determine the possibility of using ground waste material derived from the exploited structures of wind turbines as a filler in geopolymer composites. In order to determine the potential of such a solution, tests were carried out on three different fractions originating from the ground blades of wind turbines, including an analysis of the morphology and chemical composition of particles using SEM and an EDS detector, the analysis of organic and inorganic matter content and tests for multivariate geopolymer composites with the addition of waste material. The compression and flexural strength, density and absorbability tests, among others, were carried out. The composite material made of the geopolymer matrix contained the filler at the level of 5%, 15% and 30% of dry mass. The addition of the filler showed a tendency to decrease the properties of the obtained geopolymer composite. However, it was possible to obtain materials that did not significantly differ in properties from the re-reference sample for the filler content of 5% and 15% of dry mass. As a result of the research, it was found that waste materials from the utilization of used wind power plants can become fillers in geopolymer composites. It was also found that it is possible to increase the strength of the obtained material by lowering the porosity.

A Critical Review on Recycling Composite Waste Using Pyrolysis for Sustainable Development

The rising usage of carbon and glass fibers has raised awareness of scrap management options. Every year, tons of composite scrap containing precious carbon and glass fibers accumulate from numerous sectors. It is necessary to recycle them efficiently, without harming the environment. Pyrolysis seems to be a realistic and promising approach, not only for efficient recovery, but also for high-quality fiber production. In this paper, the essential characteristics of the pyrolysis process, their influence on fiber characteristics, and the use of recovered fibers in the creation of a new composite are highlighted. Pyrolysis, like any other recycling process, has several drawbacks, the most problematic of which is the probability of char development on the resultant fiber surface. Due to the char, the mechanical characteristics of the recovered fibers may decrease substantially. Chemically treating and post-heating the fibers both help to reduce char formation, but only to a limited degree. Thus, it was important to identify the material cost reductions that may be achieved using recovered carbon fibers as structural reinforcement, as well as the manufacture of high-value products using recycled carbon fibers on a large scale. Recycled fibers are cheaper than virgin fibers, but they inherently vary from them as well. This has hampered the entry of recycled fiber into the virgin fiber industry. Based on cost and performance, the task of the current study was to modify the material in such a way that virgin fiber was replaced with recycled fiber. In order to successfully modify the recycling process, a regulated optimum temperature and residence duration in post-pyrolysis were advantageous.

Wind turbine blade wastes and the environmental impacts in Canada

Electricity production by wind turbines is considered a clean energy technology, but the life cycle of wind turbines could introduce environmental risks due to waste generation, especially at the decommissioning process. This study predicts the future wind turbine blade waste arising in Canada, throughout all life cycle stages, from manufacturing until end of life, based on the installed capacities of existing Canadian wind farms and projected future installations. Five alternative strategies for managing this waste stream are assessed in terms of life cycle greenhouse gas emissions and primary energy demand, including landfilling, incineration, and mechanical recycling. For the base case scenario, it is observed that the total cumulative waste until 2050 is 275,299 tonnes, with on-site waste accounting for around 75% of this total. Waste generation is concentrated in provinces with greater wind power deployment: Ontario and Quebec alone account for 70% of total blade waste. Life cycle environmental impacts of waste management strategies are dependent on background energy systems, with incineration a significant source of greenhouse gas emissions, particularly when displacing low-carbon grid mixes. Cement kiln coprocessing achieves net zero emission by converting waste into energy and raw materials for the cement. Mechanical recycling can achieve substantial reductions in primary energy demand and greenhouse gas emissions but achieving financial viability would likely require substantial regulatory support.

Specification of Environmental Consequences of the Life Cycle of Selected Post-Production Waste of Wind Power Plants Blades

Wind power plants during generation of electricity emit almost no detrimental substances into the milieu. Nonetheless, the procedure of extraction of raw materials, production of elements and post-use management carry many negative environmental consequences. Wind power plant blades are mainly made of polymer materials, which cause a number of problems during post-use management. Controlling the system and the environment means such a transformation of their inputs in time that will ensure the achievement of the goal of this system or the state of the environment. Transformations of control of system and environment inputs, for example, blades production, are describing various models which in the research methodology, like LCA (Life Cycle Assessment), LCM (Life Cycle Management), LCI (Life Cycle Inventory), etc. require meticulous grouping and weighing of life cycle variables of polymer materials. The research hypothesis was assuming, in this paper, that the individual post-production waste of wind power plant blades is characterized by a different potential impact on the environment. For this reason, the aim of this publication is to conduct an ecological and energy life cycle analysis, evaluation, steering towards minimization and development (positive progress) of selected polymer waste produced during the manufacture of wind power plant blades. The analyzes were based on the LCA method. The subject of the research was eight types of waste (fiberglass mat, roving fabric, resin discs, distribution hoses, spiral hoses with resin, vacuum bag film, infusion materials residues and surplus mater), which are most often produced during the production of blades. Eco-indicator 99 and CED (Cumulative Energy Demand) were used as the computation procedures. The influence of the analyzed objects on human health, ecosystem quality and resources was appraised. Amidst the considered wastes, the highest level of depreciating impact on the milieu was found in the life cycle of resin discs (made of epoxy resin). The application of recycling processes would decrease the depreciating environmental influence in the context of the total life cycle of all analyzed waste. Based on the outcome of the analyzes, recommendations were proposed for the environmentally friendly post-use management of wind power plant blades, that can be used to develop new blade manufacturing techniques that better fit in with sustainable development and the closed-cycle economy.

Through the Eye of a Needle: An Eco-Heterodox Perspective on the Renewable Energy Transition

We add to the emerging body of literature highlighting cracks in the foundation of the mainstream energy transition narrative. We offer a tripartite analysis that re-characterizes the climate crisis within its broader context of ecological overshoot, highlights numerous collectively fatal problems with so-called renewable energy technologies, and suggests alternative solutions that entail a contraction of the human enterprise. This analysis makes clear that the pat notion of “affordable clean energy” views the world through a narrow keyhole that is blind to innumerable economic, ecological, and social costs. These undesirable “externalities” can no longer be ignored. To achieve sustainability and salvage civilization, society must embark on a planned, cooperative descent from an extreme state of overshoot in just a decade or two. While it might be easier for the proverbial camel to pass through the eye of a needle than for global society to succeed in this endeavor, history is replete with stellar achievements that have arisen only from a dogged pursuit of the seemingly impossible.

A Multidisciplinary Review of Recycling Methods for End-of-Life Wind Turbine Blades

Wind energy has seen an increase of almost 500 GW of installed wind power over the past decade. Renewable energy technologies have, over the years, been striving to develop in relation to capacity and size and, simultaneously, though with less focus on, the consequences and challenges that arise when the products achieve end-of-life (EoL). The lack of knowledge and possibilities for the recycling of fiber composites and, thus, the handling of EoL wind turbine blades (WTBs) has created great environmental frustrations. At present, the frustrations surrounding the handling are based on the fact that the most commonly used disposal method is via landfills. No recycling or energy/material recovery is achieved here, making it the least advantageous solution seen from the European Waste Commission’s perspective. The purpose of this research was thus to investigate the current recycling methods and to categorize them based on the waste materials. The opportunities were compared based on processing capacity, price, environment and technology readiness level (TRL), which concluded that recycling through co-processing in the cement industry is the only economical option at present that, at the same time, has the capabilities to handle large amounts of waste materials.

Development of Modular Bio-Inspired Autonomous Underwater Vehicle for Close Subsea Asset Inspection

To reduce human risk and maintenance costs, Autonomous Underwater Vehicles (AUVs) are involved in subsea inspections and measurements for a wide range of marine industries such as offshore wind farms and other underwater infrastructure. Most of these inspections may require levels of manoeuvrability similar to what can be achieved by tethered vehicles, called Remotely Operated Vehicles (ROVs). To extend AUV intervention time and perform closer inspection in constrained spaces, AUVs need to be more efficient and flexible by being able to undulate around physical constraints. A biomimetic fish-like AUV known as RoboFish has been designed to mimic propulsion techniques observed in nature to provide high thrust efficiency and agility to navigate its way autonomously around complex underwater structures. Building upon advances in acoustic communications, computer vision, electronics and autonomy technologies, RoboFish aims to provide a solution to such critical inspections. This paper introduces the first RoboFish prototype that comprises cost-effective 3D printed modules joined together with innovative magnetic coupling joints and a modular software framework. Initial testing shows that the preliminary working prototype is functional in terms of water-tightness, propulsion, body control and communication using acoustics, with visual localisation and mapping capability.

Wind turbine blade recycling: An evaluation of the European market potential for recycled composite materials

The limited literature on the cost of various recycling methodologies for thermoset composites sets the background of this work, focusing mainly on the identification of an upper and lower economic value of glass fibre recovered from wind turbine blades recycling. The study briefly reviews the materials used by various original equipment manufacturers (OEM) for wind turbine blades. Successively, it provides an overview of the various recycling methods with interest in recovered materials, mechanical and physical properties, which are used, for estimating a maximum expected value. All recycling processes show a negative effect on mechanical properties with strength loss between 30% and 60%. Process energy demands are reviewed, and considerations are set forward to estimate the minimum cost of operating mechanical, pyrolysis and fluidized bed plants in Germany. Ultimately, current applications of recovered material and related markets are explored. Through interviews and secondary data, it is highlighted that despite the lower mechanical properties, grinded material finds applications in traditional processes, cement kilns and new products. It is also found that pyrolysed fibres can be used as insulation material and oils can be easy to distil. Pyrolysis is a relatively expensive process, thereby, distillation of the oils and energy recovery are necessary enablers towards commercial viability. Mechanically grinded material presents the lowest process cost with ca. €90/tonne, thus, below landfilling and incineration and falling within the attention of private businesses. Numerous markets are available for recovered materials from wind turbine blades, primarily for grinded products and secondly for pyrolysed glass fibre.

Sustainable End-of-Life Management of Wind Turbine Blades: Overview of Current and Coming Solutions

Various scenarios of end-of-life management of wind turbine blades are reviewed. “Reactive” strategies, designed to deal with already available, ageing turbines, installed in the 2000s, are discussed, among them, maintenance and repair, reuse, refurbishment and recycling. The main results and challenges of “pro-active strategies”, designed to ensure recyclability of new generations of wind turbines, are discussed. Among the main directions, the wind turbine blades with thermoplastic and recyclable thermoset composite matrices, as well as wood, bamboo and natural fiber-based composites were reviewed. It is argued that repair and reuse of wind turbine blades, and extension of the blade life has currently a number of advantages over other approaches. While new recyclable materials have been tested in laboratories, or in some cases on small or medium blades, there are remaining technological challenges for their utilization in large wind turbine blades.

Composite Material Recycling Technology—State-of-the-Art and Sustainable Development for the 2020s

Recently, significant events took place that added immensely to the sociotechnical pressure for developing sustainable composite recycling solutions, namely (1) a ban on composite landfilling in Germany in 2009, (2) the first major wave of composite wind turbines reaching their End-of-Life (EoL) and being decommissioned in 2019–2020, (3) the acceleration of aircraft decommissioning due to the COVID-19 pandemic, and (4) the increase of composites in mass production cars, thanks to the development of high volume technologies based on thermoplastic composites. Such sociotechnical pressure will only grow in the upcoming decade of 2020s as other countries are to follow Germany by limiting and banning landfill options, and by the ever-growing number of expired composites EoL waste. The recycling of fiber reinforced composite materials will therefore play an important role in the future, in particular for the wind energy, but also for aerospace, automotive, construction and marine sectors to reduce environmental impacts and to meet the demand. The scope of this manuscript is a clear and condensed yet full state-of-the-art overview of the available recycling technologies for fiber reinforced composites of both low and high Technology Readiness Levels (TRL). TRL is a framework that has been used in many variations across industries to provide a measurement of technology maturity from idea generation (basic principles) to commercialization. In other words, this work should be treated as a technology review providing guidelines for the sustainable development of the industry that will benefit the society. The authors propose that one of the key aspects for the development of sustainable recycling technology is to identify the optimal recycling methods for different types of fiber reinforced composites. Why is that the case can be answered with a simple price comparison of E-glass fibers (~2 $/kg) versus a typical carbon fiber on the market (~20 $/kg)—which of the two is more valuable to recover? However, the answer is more complicated than that—the glass fiber constitutes about 90% of the modern reinforcement market, and it is clear that different technologies are needed. Therefore, this work aims to provide clear guidelines for economically and environmentally sustainable End-of-Life (EoL) solutions and development of the fiber reinforced composite material recycling.

Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 2/2

The process of conversion of wind kinetic energy into electricity in innovative wind power plant emits practically no harmful substances into the environment. However, the production stage of its components requires a lot of energy and materials. The biggest problem during production planning process of an innovative wind power plant is selection of materials and technologies and, consequently, the waste generated at this stage. Therefore, the aim of this publication was to conduct an environmental analysis of the life cycle of elements of a wind turbine by means of life cycle assessment (LCA) method. The object of the research was a wind power plant divided into five sets of components (tower, turbine structure, rotors, generators, and instrumentation), made mainly of steel and small amounts of polymer materials. Eco-indicator 99 was used as an analytical procedure. The impact of the subjects of analysis on human health, ecosystem quality and resources was assessed. Among the analyzed components, the highest level of negative impact on the environment was characterized by the life cycle of the wind turbine tower. The application of recycling processes is reducing the negative impact on the environment in the perspective of the entire life cycle of all studied elements of the wind power plant construction.

GoWInD: Wind Energy Spatiotemporal Assessment and Characterization of End-of-Life Activities

Concerns on the lack sustainable end-of-life options for wind turbines have significantly increased in recent years. To ensure wind energy continuous growth, this research develops a novel spatiotemporal methodology that sustainably handles end-of-life activities for wind equipment. This research introduces the Global Wind Inventory for Future Decommissioning (GoWInD), which assesses and characterizes wind turbines according to individual spatiotemporal decommissioning and sustainability attributes. Applying data from GoWInD, the research developments networks of end-of-life (EoL) centers for wind turbines. The placement and operational levels of EoL centers optimize sustainable decommissioning according to changing spatiotemporal features of wind turbines. The methodology was evaluated for the United States, developing the United States Global Wind Inventory for Future Decommissioning (US—GoWInD), implementing the network of United States end-of-life (US—EoL) centers. Significant imbalances on the temporal and spatial distribution of US wind decommissioning inventory were revealed by the system. Diverse options to effectively handle these imbalances were highlighted by the methodology, including US—EoL center optimization according to placement, operational levels and potential complementarities. Particular attention was paid to components with challenging disposal options. The system can be implemented for diverse geographical locations and alternative spatial and temporal resolutions.

Estimation of glass and carbon fiber reinforced plastic waste from end-of-life rotor blades of wind power plants within the European Union

The European Union is aiming at a circular economy and increased resource efficiency, which requires a waste management at the end-of-life of products. This is especially challenging for new and innovative products for which no recycling infrastructure exists so far. Wind power plants are such a product, for which large amounts of waste are expected within the next years as more and more plants reach their end-of-life. Especially the end-of-life rotor blades of wind power plants pose challenges with regard to waste management, since treatment options for the installed glass and carbon fiber reinforced plastics are still in a development stage. Moreover, material specific characteristics and technical aspects require separate treatment of these materials. To plan efficient treatment infrastructure, detailed knowledge on future waste streams is required. Against this background, this paper aims at estimating the mass of glass and carbon fiber reinforced plastic waste from rotor blades. To do so, we derive material specific weight functions and material specific shares to calculate the amount of installed glass and carbon fiber reinforced plastics in rotor blades. We apply normally distributed life times to project the calculated installed masses into the future and account for uncertainties within a simulation study. The estimation model is applied to a dataset of wind power plants within the European Union. Based on the considered dataset, we estimate that 570 [Mt] of fiber reinforced plastic waste will occur between 2020 and 2030 in the European Union of which 18 [Mt] are carbon fiber reinforced plastic waste.

Control the System and Environment of Post-Production Wind Turbine Blade Waste Using Life Cycle Models. Part 1. Environmental Transformation Models

Controlling the system—the environment of power plants is called such a transformation—their material, energy and information inputs in time, which will ensure that the purpose of the operation of this system or the state of the environment, is achieved. The transformations of systems and environmental inputs and their goals describe the different models, e.g., LCA model groups and methods. When converting wind kinetic energy into electricity, wind power plants emit literally no harmful substances into the environment. However, the production and postuse management stages of their components require large amounts of energy and materials. The biggest controlling problem during postuse management is wind power plant blades, followed by waste generated during their production. Therefore, this publication is aimed at carrying out an ecological, technical and energetical transformation analysis of selected postproduction waste of wind power plant blades based on the LCA models and methods. The research object of control was eight different types of postproduction waste (fiberglass mat, roving fabric, resin discs, distribution hoses, spiral hoses with resin, vacuum bag film, infusion materials residues, surplus mater), mainly made of polymer materials, making it difficult for postuse management and dangerous for the environment. Three groups of models and methods were used: Eco-indicator 99, IPCC and CED. The impact of analysis objects on human health, ecosystem quality and resources was controlled and assessed. Of all the tested waste, the life cycle of resin discs made of epoxy resin was characterized by the highest level of harmful technology impact on the environment and the highest energy consumption. Postuse control and management in the form of recycling would reduce the negative impact on the environment of the tested waste (in the perspective of their entire life cycle). Based on the results obtained, guidelines and models for the proecological postuse control of postproduction polymer waste of wind power plants blades were proposed.

Eco-Design of Energy Production Systems: The Problem of Renewable Energy Capacity Recycling

Due to the rapid development of recycling technologies in recent years, more data have appeared in the literature on the environmental impact of the final stages of the life cycle of wind and solar energy. The use of these data in the eco-design of modern power generation systems can help eliminate the mistakes and shortcomings when planning wind and solar power plants and make them more eco-efficient. The aim of this study is to extend current knowledge of the environmental impacts of most common renewables throughout the entire life cycle. It examines recent literature data on life cycle assessments of various technologies for recycling of wind turbines and photovoltaic (PV) panels and develops the recommendations for the eco-design of energy systems based on solar and wind power. The study draws several general conclusions. (i) The contribution of further improvements in PV’s recycling technologies to environmental impacts throughout the entire life cycle is insignificant. Therefore, it is more beneficial to focus further efforts on economic parameters, in particular, on achieving the economic feasibility of recycling small volumes of PV-waste. (ii) For wind power, the issue of transporting bulky components of wind turbines to and from the installation location is critical for improving the eco-design of the entire life cycle.

Offshore and onshore wind turbine blade waste material forecast at a regional level in Europe until 2050

Wind power is a key renewable electricity source for Europe that is estimated to further develop significantly by 2050. However, the first generation of wind turbines is reaching their End of Life and the disposal of their blades is becoming a crucial waste management problem. Wind turbine blades consist primarily of reinforced composites and currently there is a lack of a sustainable solution to recycle them. The aim of this study is to estimate the wind turbine blade waste material for Europe until 2050 and is the first study adopting a high geographical granularity level in Europe, while distinguishing between offshore and onshore. In addition, the wind turbines' lifespan is not considered as a fixed value, but rather as a stochastic distribution based on historic decommissioning data. This study can support researchers, practitioners and policy makers to understand the future evolution of the blade waste material availability, identify local hotspots and opportunities and assess potential circular economy pathways. The results indicate that wind power capacity in Europe will reach 450 GW in 2050 with the respective total yearly blade waste material reaching 325,000 t. Findings for selected countries reveal that in 2050 Germany will have the majority of blade waste material from onshore wind and the United Kingdom from offshore. There is also a significant fluctuation in the yearly amount of waste expected at the country level, for several countries. Finally, local hotspots of blade waste material are identified.

A circular economy approach to green energy: Wind turbine, waste, and material recovery

Wind energy has been considered as one of the greenest renewable energy sources over the last two decades. However, attention is turning to reducing the possible environmental impacts from this sector. We argue that wind energy would not be effectively "green" if anthropogenic materials are not given attention in a responsible manner. Using the concept of the circular economy, this paper considers how anthropogenic materials in the form of carbon fibers can reenter the circular economy system at the highest possible quality. This paper first investigates the viability of a carbon-fiber-reinforced polymer extraction process using thermal pyrolysis to recalibrate the maximum carbon fiber value by examining the effect of (a) heating rate, (b) temperature, and (c) inert gas flow rate on char yield. With cleaner and higher quality recovered carbon fibers, this paper discusses the economic preconditions for the takeoff and growth of the industry and recommends the reuse of extracted carbon fibers to close the circular economy loop.

Critical Factors for the Recycling of Different End-of-Life Materials: Wood Wastes, Automotive Shredded Residues, and Dismantled Wind Turbine Blades

Different classes of wastes, namely wooden wastes, plastic fractions from automotive shredded residues, and glass fiber reinforced composite wastes obtained from dismantled wind turbines blades were analyzed in view of their possible recycling. Wooden wastes included municipal bulky wastes, construction and demolition wastes, and furniture wastes. The applied characterization protocol, based on Fourier transform infrared (FTIR) spectroscopy in attenuated total reflection (ATR) mode, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX), and thermogravimetric analysis (TG) coupled with FTIR spectrometry for the investigation of the evolved gases, revealed that the selected classes of wastes are very complex and heterogeneous materials, containing different impurities that can represent serious obstacles toward their reuse/recycling. Critical parameters were analyzed and discussed, and recommendations were reported for a safe and sustainable recycling of these classes of materials.

Resourcing the Fairytale Country with Wind Power: A Dynamic Material Flow Analysis

Wind energy is key to addressing the global climate challenge, but its development is subject to potential constraints of finite primary materials. Prior studies on material demand forecasting of wind power development are often limited to a few materials and with low technological resolution, thus hindering a comprehensive understanding of the impact of microengineering parameters on the resource implications of wind energy. In this study, we developed a component-by-component and stock-driven prospective material flow analysis model and used bottom-up data on engineering parameters and wind power capacities to characterize the materials demand and secondary supply potentials of wind energy development in Denmark, a pioneering and leading country in wind power. We also explicitly addressed the uncertainties in the prospective modeling by the means of statistical estimation and sensitivity analysis methods. Our results reveal increasing challenges of materials provision and end-of-life (EoL) management in Denmark's ambitious transition toward 100% renewable energy in the next decades. Harnessing potential secondary resource supply from EoL and extending lifetime could curtail the primary material demand, but they could not fully alleviate the material supply risk. Such a model framework that considers bottom-up engineering parameters with increased precision could be applied to other emerging technologies and help reveal synergies and trade-offs of relevant resource, energy, and climate strategies in the future renewable energy and climate transition.

Recycled Glass Fibres from Wind Turbines as a Filler for Poly(Vinyl Chloride)

This paper presents the method of using glass fibre with carbon deposit (GFCD), derived from the recycling of wind turbine blades, for production of composite materials based on poly(vinyl chloride) (PVC). Composite materials containing from 1 to 15 wt% of GFCD were produced by plasticising with a plastographometer and then by pressing. The processability and performance were studied. Mechanical properties in static tension, impact strength, and thermal stability were determined. Glass transition temperature was also determined by means of the dynamic mechanical thermal analysis (DMTA). The GFCD percentage of up to 15 wt% was found not to slightly affect the change in the processability, thermal stability, and glass transition temperature. PVC/GFCD composite materials are characterised by a definitely greater elastic modulus with simultaneous decrease of tensile strength and impact strength. An analysis with scanning electron microscopy revealed good adhesion between the filler and the polymer matrix.

A Review of the Potential for the Recovery of Wind Turbine Blade Waste Materials

A successful circular economy can only exist when it relies solely on renewable energy sources. The adoption of resilient business models and the consequent redesign of legislation on all sectors are essential to ensure sustainable economic growth. Wind energy can offer clean and renewable energy with a low environmental impact. Nevertheless, waste in end of life composite materials resulting from wind turbines is a problem that needs to be addressed. Composite materials are commonly used in wind turbines due to their excellent mechanical properties, matched by low weight. Notably, the recycling technologies of such materials is limited. Material flows and estimations of end of life materials are of great importance and will convince stakeholders that markets for recycling composites are viable investments.

Recycled wind turbine blades as a feedstock for second generation composites

With an increase in renewable wind energy via turbines, an underlying problem of the turbine blade disposal is looming in many areas of the world. These wind turbine blades are predominately a mixture of glass fiber composites (GFCs) and wood and currently have not found an economically viable recycling pathway. This work investigates a series of second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness. The refined particle size, moisture content and resin content were assessed for their influence on the properties of recycled composites. Static bending, internal bond and water sorption properties were obtained for all composites panels. Overall improvement of mechanical properties correlated with increase in resin content, moisture content, and particle size. The current investigation demonstrates that it is feasible and promising to recycle the wind turbine blade to fabricate value-added high-performance composite.