Wind Turbine Manufacturers Research Articles

A comparative analysis of carbon reduction potential for directly driven permanent magnet and doubly fed asynchronous wind turbines

AbstractWind power generation does not emit greenhouse gases or pollutants, but there are some carbon emissions from the manufacturing, transportation, operation, and waste disposal of wind turbines. Directly driven permanent magnet and doubly fed asynchronous wind turbines currently have the largest market share in China, but few Chinese studies have compared their differences in carbon reduction potential. This paper uses life cycle assessment (LCA) to quantitatively analyze the full life cycle carbon emissions of the two wind turbines to determine which type of wind turbine has greater carbon reduction potential, obtaining the following results. (1) The full life cycle greenhouse gas emissions of 2.5 MW directly driven permanent magnet and doubly fed asynchronous wind turbines are 8.48 and 10.43 g CO2/kWh, respectively. The direct‐driven permanent magnet wind turbine is superior in terms of carbon reduction. (2) The stage with the greatest impact and the greatest difference between the two wind turbines in the full life cycle is the production stage, during which the carbon emissions of the directly driven permanent magnet and doubly fed asynchronous wind turbines are 1.045 × 106 and 1.210 × 106 kg, respectively. (3) According to sensitivity analysis, proper waste disposal and transportation can reduce carbon emissions from wind turbines. These research findings can be used to help achieve carbon peaking and neutrality goals, as well as the technological development of wind power enterprises.

The embeddedness of companies in regional energy transitions

ABSTRACT Both place-specific context conditions and the interplay of a variety of actors influence regional energy transitions. Yet, the role of regional lead companies and how they are embedded in regional transitions has not been systematically analysed, even though a lack of embeddedness in their geographical context could possibly impede transitions. In our contribution, we expand transition studies with insights from economic geography and sociology to grasp the embeddedness of regional lead companies in regional transitions along ten indicators. We analyse how intra-organizational and regional factors influence these indicators and the overall degree of embeddedness. Finally, we reflect on how the (dis)embeddedness of companies affects regional energy transitions. Empirically, our analysis is based on a most different case study design, comparing a wind turbine manufacturer and its detached relation to the energy transition around a city in Central Germany with a wind project developer deeply embedded in a rural Northern German district. These findings are mirrored not only in different embeddedness degrees, but also in different types of embeddedness that we term ‘transactional’ and ‘transformational’. By systematically describing the interrelation between organizations and regions, our contribution shows how multifaceted embeddedness is and how closely inner-organizational factors are intertwined with regional transitions.

Construction and Cost Analysis of BladeBridges Made from Decommissioned FRP Wind Turbine Blades

This paper describes repurposing projects using decommissioned wind turbine blades in bridges conducted under a multinational research project entitled “Re-Wind”. Repurposing is defined by the Re-Wind Network as the re-engineering, redesigning, and remanufacturing of a wind blade that has reached the end of its life on a turbine and taken out of service and then reused as a load-bearing structural element in a new structure (e.g., bridge, transmission pole, sound barrier, seawall, shelter). The issue of end-of-life of wind turbine blades is becoming a significant sustainability concern for wind turbine manufacturers, many of whom have committed to the 2030 or 2040 sustainability goals that include zero-waste for their products. Repurposing is the most sustainable end-of-life solution for wind turbine blades from an environmental, economic, and social perspective. The Network has designed and constructed two full-size pedestrian/cycle bridges—one on a greenway in Cork, Ireland and the other in a quarry in Draperstown, Northern Ireland, UK. The paper describes the design, testing, and construction of the two bridges and provides cost data for the bridges. Two additional bridges that are currently being designed for construction in Atlanta, GA, USA are also described. The paper also presents a step-by-step procedure for designing and building civil structures using decommissioned wind turbine blades. The steps are: project planning and funding, blade sourcing, blade geometric characterization, material testing, structural testing, designing, cost estimating, and construction.

Towards full electrical certification of wind turbines on test benches - experiences gained from the HiL-GridCoP project

In recent years, more and more wind turbine manufacturers have been using test benches, such as the Dynamic Nacelle Testing Laboratory at Fraunhofer IWES in Bremerhaven, to test and optimize their turbines. To further accelerate the test phases, Fraunhofer IWES, together with the project partners Nordex Energy SE & Co. KG and Vestas Wind Systems A/S, has built a new test bench for grid compliance testing of reduced systems, consisting of the generator, the converter, and the transformer plus control as well as protection system. The HiL-GridCoP project demonstrated the comparability of test bench measurements on a wind turbine equipped with a doubly-fed induction generator with field measurements performed using a fault ride-through container. The aim of this paper is to present some of the key findings related to the electrical commissioning and test execution. The focus is on the grid simulator and on its impedance simulation functionality. It is discussed which limitations may be caused by specific test bench components and which issues might affect the test results. Finally, some measurements of voltage dips are presented to verify the test bench's comparability with field tests so that the full electrical certification can be carried out next.

New pathways to future grid compliance for wind power plants

Over the last decade, the rapid growth of wind power is driving an increase of efforts in defining the frameworks and rules for the connection of wind power plants (WPPs) through the grid codes and standards, making testing/validation more demanding and complex for wind turbine (WT) manufacturers and WPP developers. Traditionally, WT manufacturers carry out grid compliance tests at full-scale prototype turbines whereas WPP developers and Transmission System Operators (TSOs) mainly perform studies for new WPPs based on offline RMS and EMT simulations. Until now, these strategies have been sufficient for ensuring grid compliance of WTs and WPPs, however moving forward the wind sector needs new testing methods to meet the increasing WT capacity, WPP complexity, and deployment pace to achieve society's desired sustainability targets. In this paper, the emerging strategies that target these challenges are presented as: a) subsystems and component testing of WTs specified in IEC 61400- 21-4; b) - hardware-in-the-loop (HiL) real time simulation for WT/WPP control and protection appraisals (future 61400-21-5). Finally, a future outlook is given on the importance of addressing model validation and how these strategies can be complemented with other modern analytical tools such as artificial intelligence/machine learning, data-driven dynamic modelling, digital twin technology, and software-in-the-loop (SiL) real time simulation.

WTG manufacturer's experience with subsystem and component validation for wind turbines

Conventionally, wind turbine (WT) manufacturers are performing grid compliance tests at the WT level primarily in the field to verify the WT capabilities and performances against certain grid code requirements and validate simulation models accuracy and performance. Such compliance tests are becoming more challenging and numerous due to the growing number of relevant grid code requirements and the rapid growth of WT's size and rating, which in turn require more powerful test equipment and larger sites to test such turbines. Upcoming standards such as IEC 61400-21-4 and FGW AK KEZ and other industry initiatives aim to address these challenges through the replacement of site-specific tests with tests performed on WT components and subsystems in a controlled test bench environment. This paper presents the experience gathered so far on various test benches including nacelle, electrical generation, converter, and real time digital simulator test benches. The results of these different test benches brought important lessons regarding the transferability of the results through the evaluation and comparison with one another and benchmarking against site specific tests to assess their accuracy in representing the performance, capability, and functionality at WT level. Finally, a long-term grid compliance strategy, revolved around on moving part of the testing campaign to subsystem and component testing and modelling, is presented with a proposal of new test bench and acceptance strategies for the industry.

The effect of icing severity on wind turbine ice protection systems efficiency

In the past years, there has been a gain of interest in wind turbine Ice Protection Systems (IPS) as wind farm owners realize the extent of their ice-induced losses. More and more wind turbine manufacturers are now offering IPSs in their cold climate packages. IPS retrofits are now available to minimize icing losses on existing unheated wind turbines. With this growth in interest, questions about the efficiency of those systems arise. Field experience has shown that these systems can be ineffective in certain ambient conditions which led to the concept of IPS performance envelopes. These envelopes lay out on a wind speed vs ambient temperature map the conditions where IPSs are expected to be effective. While these envelopes can give a good overlook of the IPSs efficiency in post-icing conditions, they neglect the effect that icing severity can have on IPS effectiveness. This paper presents a simple 1D model for hot-air IPS able to generate performance envelopes considering the icing severity. This model was validated with the production data of six different icing events. It has been shown to be coherent with the observed efficiency of the hot air IPS.

Active Wake Steering Control Data-Driven Design for a Wind Farm Benchmark

Upstream wind turbines yaw to divert their wakes away from downstream turbines, increasing the power produced. Nevertheless, the majority of wake steering techniques rely on offline lookup tables that translate a set of parameters, including wind speed and direction, to yaw angles for each turbine in a farm. These charts assume that every turbine is working well, however they may not be very accurate if one or more turbines are not producing their rated power due to low wind speed, malfunctions, scheduled maintenance, or emergency maintenance. This study provides an intelligent wake steering technique that, when calculating yaw angles, responds to the actual operating conditions of the turbine. A neural network is trained online to calculate yaw angles from operating data, including turbine status, using a hybrid model and learning-based active control method. The proposed control solution does not need to solve optimization problems for each combination of the turbines’ non-optimal working conditions in a farm, as opposed to purely model-based approaches that use lookup tables provided by the wind turbine manufacturer or generated offline. Instead, the integration of learning strategy into the control design enables the creation of an active control scheme. The suggested methodology differs from solely learning-based approaches in that it doesn't call for a significant number of training samples, such as in model-free reinforcement learning. In actuality, by taking use of the model during backpropagation, the suggested approach learns more from each sample. Using a well-known and practical wind farm benchmark, results are reported for both standard (nominal) wake steering under operational conditions with all turbines and for faulty conditions.

Суждение о формировании экономического и технологического развития ветроэнергетики

Russia’s energy security is a critical infrastructure for economic and national integrity. The study examines the possibilities for creating alternative generating energy capacities using renewable energy sources – wind farms. The attention of the world community in climate conservation on a planetary scale is noted, which is expressed in multilateral agreements and other legal acts that make up the international institutional framework for the development of renewable energy. It is indicated that the presence of high technologies and exceptional competencies of the world’s leading companies create conditions for the production of unique wind turbines and the development of a software and hardware system for managing wind farms. On the basis of technologies developed in world practice for the construction of wind turbines and wind farms. A proposal was made on the need to develop high-tech industries to create wind power plants of various capacities for the climatic conditions of Russia, which will increase the economic and technological potential of the country’s regions. It has been determined that the energy efficiency largely depends on the availability of innovative technologies, research and development, highly qualified specialists, and financial resources of companies. The largest modern manufacturers of wind turbines in economic regions, the trends of their further expansion are presented. The purpose of the study is to assess the state and dynamics of the prospective development of wind power plants in the global energy sector.

Accurate Stall Prediction for Thick Airfoil by Delayed Detached-Eddy Simulations

The continuous increase in wind turbine blade length raises a serious question about how to effectively reduce the blade mass. As one of the solutions, recently, some wind turbine manufacturers are moving towards longer blades with thicker airfoils. As most of the numerical simulation experiences are based on thin airfoils, the present paper focused on airfoils with thickness to chord ratios of 30% and specifically focused on the influence of spanwise length on the numerical results. Airfoils with a spanwise length of 0.1 to 5 chords were simulated utilizing the Delayed Detached-Eddy Simulations (DDES) approach. One of the important objectives was to identify the necessary grid resolution and configuration while still maintaining accuracy under a deep stall situation. It was found that the spanwise length of the computational domain had a crucial influence on the prediction of lift and drag. At a stall angle of attack, the aerodynamic force could not be accurately predicted when the airfoil span was reduced to 0.3 chords, even with a high grid density. The periodicity of the spanwise flow was clearly visible when the airfoil span was extended to 5 chords.

Fatigue reliability of wind turbines: historical perspectives, recent developments and future prospects

Wind, as a sustainable and affordable energy source, represents a strong alternative to traditional energy sources. However, wind power is only one of the options, together with other renewable energy sources. Consequently, the core concerns for wind turbine manufacturers and operators are to increase its reliability and decrease costs, therefore enhancing commercial competitiveness. Among typical failure modes of wind turbines, fatigue is a common and critical source. Given the significance of fatigue reliability in wind turbine structural integrity, reliable probabilistic fatigue theories are necessary for design scheme optimization. By reducing the expenses on manufacturing, operation, and maintenance in reliability- and cost-optimal ways, the cost of energy can be significantly reduced. This study systematically reviews the state-of-the-art technology for fatigue reliability of wind turbines, and elaborates on the evolution of methodology in wind load uncertainty modelling. In addition, fatigue reliability assessment techniques on four typical components are summarized. Finally, discussions and conclusions are presented, intending to provide direct insights into future theoretical development and methodological innovation in this field.

Employing a Socio-Technical System Approach in Prospective Life Cycle Assessment: A Case of Large-Scale Swedish Sustainable Aviation Fuels

Ambitious fossil-free targets imposed on the aviation industry worldwide demand a large volumetric supply of sustainable aviation fuel (SAF) to meet. Sweden's commitment to a 30% volume SAF blending target by 2030 attracts interest in local production. However, the sustainability of local production is largely unknown. Addressing this gap, we aim to explore potential SAF technology pathways and assess their environmental performances in Sweden. To do so, we utilize a socio-technical system (STS) approach for pathways selection and prospective life cycle assessment (LCA) for environmental impact assessment. As a result, we identify two lignocellulosic-based and two electrofuel-based pathways and evaluate their global warming potential, mineral depletion potential, ionizing radiation, land use, freshwater ecotoxicity and human toxicity impact in comparison to jet fuel. Our findings show that the well-to-wake global warming potential (100 years) of 30% SAF is on average 20% lower than that of jet fuel, with non-carbon dioxide species emitted in flight being the major contributors, prompting the need for urgent research efforts to mitigate their potential impacts. Under the assumption that no burdens are allocated to waste material used as feedstock, lignocellulosic-based 100% SAF has a well-to-pump climate impact (100 years) ranging from 0.6 to 1.5 g CO2−eq/MJ compared to jet fuel's 10.5 g CO2−eq/MJ. In contrast, the well-to-pump climate impact (100 years) of electrofuel-based 100% SAF (ranging from 7.8 to 8.2 g CO2−eq/MJ) is only marginally lower than that of jet fuel, mainly attributed to emissions from steel and concrete produced for wind turbine manufacturing. In general, the use of electricity generated by wind power could shift the potential environmental burden associated with jet fuel from global warming to mineral depletion, land use, freshwater ecotoxicity and human toxicity. The STS approach underscores the need to prioritize changes in systems underpinning SAF production, in turn supporting policy and investment decision making.

A Review of the Development of Key Technologies for Offshore Wind Power in China

In recent years, Offshore Wind Power (OWP) has gained prominence in China’s national energy strategy. However, the levelized cost of electricity (LCoE) of wind power must be further reduced to match the average wholesale price. The cost-cutting and revenue-generating potential of offshore wind generation depends on technological innovation. The most recent studies and applications of offshore wind technology are thoroughly examined. (1) Techniques for site selection, such as site surveys, wind resource assessments, and environmental factors, are reviewed. (2) Three main technical components in offshore wind farms are discussed, including wind turbine, foundations, and booster stations. (3) The state-of-the-art method of the offshore wind farm’s construction and operation and maintenance (O&M) practices is discussed. In situ marine geological surveying, large-scale offshore wind turbine manufacturing, integrated structural design, floating foundation design, flexible DC transmission technology, shortage of specialized vessels and equipment for construction, intelligence of O&M, and other issues are challenging China’s OWP industry. A brief overview of China’s efforts in standardization, parity, and research and development are discussed. Recommendations for future development of the wind power industry are provided for China, which may be referable for other nations with comparable circumstances.

Improved wind turbine parts

Wind turbine manufacturer Vestas benefitted from an end-to-end additive manufacturing (AM) process which reduces downtime and improves part quality.

Research on the Impact of the Cancellation of State Subsidies on Stakeholders of Offshore Wind Power

Public subsidies for offshore wind power will be eliminated in 2022. At present, offshore wind power still depends on subsidies. In this new situation, it is necessary to study the influence on the stakeholders and how the offshore wind power industry achieves healthy and sustainable development. Firstly, this paper qualitatively analyzes the impact of the cancellation of state subsidies on offshore wind turbine manufacturers and developers and finds that if there is no subsidy to relay offshore wind power, the development of offshore wind power will stagnate, and the wind turbine manufacturers will face great challenges. Then, by constructing the subsidy demand calculation model and the transmission and distribution price cross subsidy calculation model according to China’s electricity price-related policies, the results show that the local subsidy is basically feasible to continue the national subsidy, and the burden is decreasing year by year, so the relay subsidy should be continued. Based on the cloud model, an evaluation model for the development of offshore wind power benefits from the cancellation of national subsidies is constructed to quantify the impact of the cancellation of overseas subsidies on local governments and power grid enterprises. According to the example analysis, under the background of the cancellation of national subsidies, Guangdong has the best development of offshore wind power benefits, which verifies the feasibility of the proposed model.

Insights from detailed numerical investigation of 15 MW offshore semi-submersible wind turbine using aero-hydro-servo-elastic code

Offshore wind turbines are getting larger in terms of dimensions to maximize power generation. Large wind turbine offshore structures can be installed in deep water locations, where they have the advantage to generate higher power due to high wind speeds. To achieve this, wind turbine manufacturers are introducing larger and scaled-up designs to meet the global energy demands. However, these models suffer from large structural loads and deformations when subjected to varying environmental loadings. Therefore, it is necessary to fully comprehend the multibody coupled dynamics of such large offshore structures before proceeding towards their installation in open oceans. This paper carries out an extensive investigation on the ultimate load analysis and fully coupled dynamic response of the 15 MW reference turbine mounted over a UMaine VolturnUS-S semi-submersible floating platform. We used OpenFAST to carry out the stability and full-system linearization studies followed by a detailed time-domain analysis for the power production, parked and fault conditions. We began with a brief background theory on linearization and eigenanalysis for identifying the natural frequencies followed by discussion of the Campbell diagram showing the full-system natural frequencies. It was observed that the multi-blade coordinate code does not correctly pick the natural frequencies. Additional free decay tests have been carried out to verify the full-system natural frequencies. The variation of mean, minimum and maximum values of various characteristic loads and platform motions with respect to different environmental conditions are also presented. We also discussed the change in dynamic response due to the yaw misalignment, wind–wave misalignment, and second-order wave forces. The parked and fault conditions were found to be the critical design load cases (DLCs) for the design of IEA 15 MW wind turbine mounted on Volturn US-S semi-submersible. Furthermore, this paper gives an insight of the important DLCs to be considered while computing the design loads for similar large wind turbine structures.

Anamorphic beam shaping system designed to optimize irradiance distribution in the Cofiblas process for glass nanofibers production

Glass fibers play a key role as reinforcements in composite materials, where increasing mechanical properties at affordable costs are required in applications such aerospace, automotive and wind turbine manufacturing. The production of glass nanofibers augurs a substantial enhancement of their performance. However, although different techniques are currently used to produce glass, polymer or carbon nanofibers, none of them is practical to continuously produce solid, non-porous and separated glass nanofibers with capability to feasibly scaling up for mass production. The continuous fiberizing by laser melting (Cofiblas), makes possible to obtain ultrafine fibers with virtually infinite length.Here, we provide a deep analysis on the influence of the laser beam shaping system on the performance of the Cofiblas technique. Two different optical systems are compared: the first one consists of a beam-splitter coupled to a set of mirrors and spherical lenses. While the second one, is based on an anamorphic system comprising a simple combination of cylindrical and spherical lenses. Both configurations are evaluated and compared in several sets of experiments with the main target of obtaining continuous glass nanofibers with the smallest diameter. The anamorphic system generates an elliptical Gaussian distribution of the laser beam irradiance, which increases the energy absorbed by the preform. As a result, continuous silica nanofibers with diameters 84.5% smaller are obtained with the anamorphic system, compared with the optical system constituted by spherical lenses.

Ultrahigh-Field, High-Efficiency Superconducting Machines for Offshore Wind Turbines

Offshore wind turbines are the key enabling technology to increase the green energy penetration in the electricity market. Increasing the power generation per tower and reducing the levelized cost of energy are the two significant problems faced by wind turbine manufacturers. Traditional turbine manufacturers use rare-earth permanent magnets (PMs) to increase the air-gap flux density and maximize the machine outer diameter (OD) to increase the torque output. Since the air-gap flux density achievable with available PM is limited, increasing the power output of a traditional generator invariably leads to a significant increase in the volume and mass on top of the turbine tower and associated manufacturing, transportation, and installation costs. Superconducting (SC) wind turbine generators offer 5 to 10 times the air-gap flux density of a PM generator, and a corresponding increase in specific power and power density. Previous MW scale SC wind turbines designs used heavy back iron in the design, iron saturation limits the achievable air-gap flux density in the designs and resulted in bulky generators and moderate efficiency. In this article, a hybrid design approach is proposed to reach an ultrahigh field (5 to 10 times of PM air-gap flux density) and high efficiency (>98%) SC wind turbine for offshore wind turbine. An additional stray field limitation is introduced for safety concerns and shielding techniques are explored. Electromagnetic, mechanical, and cooling designs are provided to support the feasibility of proposed SC wind turbines. A nacelle integration inside a commercially available 6 MW wind turbine is shown to demonstrate the size comparison of the proposed generator.

Stall-induced vibrations analysis and mitigation of a wind turbine rotor at idling state: Theory and experiment

With the development of wind turbine manufacturing technology, the wind turbine rotor is facing more design challenges for exposing to complex environmental conditions and severe wind loads. This paper investigates the stall-induced vibrations of a wind turbine rotor operating at idling state, and a strategy to mitigate the stall-induced vibrations is proposed. The equations of motion of the wind turbine rotor are established by Hamilton's principle and solved using the finite element method (FEM). The aerodynamic forces are evaluated based on the blade element theory, and the aero-damping is obtained by solving the eigenvalue problem of the rotor system. The stability of the wind turbine rotor is analyzed under different wind speeds, wind deviation angles, azimuth angles and pitch angles. The calculation results show that negative aero-damping exists in specific wind deviation angles, which leads to the divergence of edge-wise motions of the blades. An on-site experimental study validates the criteria of stability of the wind turbine rotor. The present work provides positive outlooks for aeroelastic analysis of the wind turbine blades at idling states, and it is significant for the design and safety improvement of large wind turbine blades.

Technological expertise as a driver of environmental technology diffusion through trade: Evidence from the wind turbine manufacturing industry

Only a small number of companies, located in a few countries, have specific technological expertise in wind turbine manufacturing. Such technological expertise is found to be a significant driver of trade in wind turbines. In addition, it is found that countries’ wind power generation efficiency depends on having access to higher quality wind turbines available in international markets. Trade in wind turbines can thus be seen as tantamount to trading (wind) technologies that deliver a level of efficiency that cannot be replicated in importing countries. These results have important policy implications: i) Barriers to trade in wind turbines are also barriers to the dissemination of key environmental technologies needed by countries where they have not been developed; ii) Trade-discriminatory measures can also be a hurdle to non-manufacturing job creation as the latter hinges on the continuous deployment of solar energy, which in turn depends on access to international markets where high quality wind turbines are found; iii) Industrial policies should not focus on the creation of national champions but rather on ensuring that domestic firms can apply their specific capabilities to new opportunities in global industries.