Articles | Volume 7, issue 3
https://doi.org/10.5194/wes-7-1209-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wes-7-1209-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 Jun 2022
Research article |
| 08 Jun 2022
| 08 Jun 2022
Impacts of wind field characteristics and non-steady deterministic wind events on time-varying main-bearing loads
Wind Energy and Control Centre, Department of Electronic and Electrical Engineering, The University of Strathclyde, Glasgow, UK
Adam Stock
Wind Energy and Control Centre, Department of Electronic and Electrical Engineering, The University of Strathclyde, Glasgow, UK
George Elderfield
Wind Energy and Control Centre, Department of Electronic and Electrical Engineering, The University of Strathclyde, Glasgow, UK
Robin Elliott
Onyx Insight, Nottingham, United Kingdom
James Brasseur
Aerospace Mechanics Research Center, University of Colorado, Boulder, United States
Jonathan Keller
National Renewable Energy Laboratory, Golden, United States
Yi Guo
National Renewable Energy Laboratory, Golden, United States
Wooyong Song
ORE Catapult, Inovo, Glasgow, United Kingdom
Related authors
Piotr Fojcik, Edward Hart, and Emil Hedevang
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-17, https://doi.org/10.5194/wes-2025-17, 2025
Preprint under review for WES
Short summary
Short summary
Increasing the efficiency of wind farms can be achieved via reducing the impact of wakes: flow regions with lower wind speed occurring downwind from turbines. This work describes training and validation of a novel method for estimation of the wake effects impacting a turbine. The results show that for most tested wind conditions, the developed model is capable of robust detection of wake presence, and accurate characterisation of its properties. Further validation and improvements are planned.
Edward Hart
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2024-187, https://doi.org/10.5194/wes-2024-187, 2025
Preprint under review for WES
Short summary
Short summary
A parametric model for the wind direction rose is presented, with testing on real offshore wind farm data indicating the model is indeed representative. The presented model provides opportunities for standardisation and enables more systematic analyses of wind direction impacts and sensitivities.
Scott Dallas, Adam Stock, and Edward Hart
Wind Energ. Sci., 9, 841–867, https://doi.org/10.5194/wes-9-841-2024, https://doi.org/10.5194/wes-9-841-2024, 2024
Short summary
Short summary
This review presents the current understanding of wind direction variability in the context of control-oriented modelling of wind turbines and wind farms in a manner suitable to a wide audience. Motivation comes from the significant and commonly seen yaw error of horizontal axis wind turbines, which carries substantial negative impacts on annual energy production and the levellised cost of wind energy. Gaps in the literature are identified, and the critical challenges in this area are discussed.
Edward Hart, Elisha de Mello, and Rob Dwyer-Joyce
Wind Energ. Sci., 7, 1533–1550, https://doi.org/10.5194/wes-7-1533-2022, https://doi.org/10.5194/wes-7-1533-2022, 2022
Short summary
Short summary
This paper is the second in a two-part study on lubrication in wind turbine main bearings. Investigations are conducted concerning lubrication in the double-row spherical roller main bearing of a 1.5 MW wind turbine. This includes effects relating to temperature, starvation, grease-thickener interactions and possible non-steady EHL effects. Results predict that the modelled main bearing would be expected to operate under mixed lubrication conditions for a non-negligible proportion of its life.
Edward Hart, Elisha de Mello, and Rob Dwyer-Joyce
Wind Energ. Sci., 7, 1021–1042, https://doi.org/10.5194/wes-7-1021-2022, https://doi.org/10.5194/wes-7-1021-2022, 2022
Short summary
Short summary
This work provides an accessible introduction to elastohydrodynamic lubrication theory as a precursor to analysis of lubrication in a wind turbine main bearing. Fundamental concepts, derivations and formulas are presented, followed by the more advanced topics of starvation, non-steady effects, surface roughness interactions and grease lubrication.
Amir R. Nejad, Jonathan Keller, Yi Guo, Shawn Sheng, Henk Polinder, Simon Watson, Jianning Dong, Zian Qin, Amir Ebrahimi, Ralf Schelenz, Francisco Gutiérrez Guzmán, Daniel Cornel, Reza Golafshan, Georg Jacobs, Bart Blockmans, Jelle Bosmans, Bert Pluymers, James Carroll, Sofia Koukoura, Edward Hart, Alasdair McDonald, Anand Natarajan, Jone Torsvik, Farid K. Moghadam, Pieter-Jan Daems, Timothy Verstraeten, Cédric Peeters, and Jan Helsen
Wind Energ. Sci., 7, 387–411, https://doi.org/10.5194/wes-7-387-2022, https://doi.org/10.5194/wes-7-387-2022, 2022
Short summary
Short summary
This paper presents the state-of-the-art technologies and development trends of wind turbine drivetrains – the energy conversion systems transferring the kinetic energy of the wind to electrical energy – in different stages of their life cycle: design, manufacturing, installation, operation, lifetime extension, decommissioning and recycling. The main aim of this article is to review the drivetrain technology development as well as to identify future challenges and research gaps.
James Stirling, Edward Hart, and Abbas Kazemi Amiri
Wind Energ. Sci., 6, 15–31, https://doi.org/10.5194/wes-6-15-2021, https://doi.org/10.5194/wes-6-15-2021, 2021
Short summary
Short summary
This paper considers the modelling of wind turbine main bearings using analytical models. The validity of simplified analytical representations is explored by comparing main-bearing force reactions with those obtained from higher-fidelity 3D finite-element models. Results indicate that good agreement can be achieved between the analytical and 3D models in the case of both non-moment-reacting (such as for a spherical roller bearing) and moment-reacting (such as a tapered roller bearing) set-ups.
Edward Hart, Benjamin Clarke, Gary Nicholas, Abbas Kazemi Amiri, James Stirling, James Carroll, Rob Dwyer-Joyce, Alasdair McDonald, and Hui Long
Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, https://doi.org/10.5194/wes-5-105-2020, 2020
Short summary
Short summary
This paper presents a review of existing theory and practice relating to main bearings for wind turbines. Topics covered include wind conditions and resulting rotor loads, main-bearing models, damage mechanisms and fault detection procedures.
Piotr Fojcik, Edward Hart, and Emil Hedevang
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-17, https://doi.org/10.5194/wes-2025-17, 2025
Preprint under review for WES
Short summary
Short summary
Increasing the efficiency of wind farms can be achieved via reducing the impact of wakes: flow regions with lower wind speed occurring downwind from turbines. This work describes training and validation of a novel method for estimation of the wake effects impacting a turbine. The results show that for most tested wind conditions, the developed model is capable of robust detection of wake presence, and accurate characterisation of its properties. Further validation and improvements are planned.
Edward Hart
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2024-187, https://doi.org/10.5194/wes-2024-187, 2025
Preprint under review for WES
Short summary
Short summary
A parametric model for the wind direction rose is presented, with testing on real offshore wind farm data indicating the model is indeed representative. The presented model provides opportunities for standardisation and enables more systematic analyses of wind direction impacts and sensitivities.
Scott Dallas, Adam Stock, and Edward Hart
Wind Energ. Sci., 9, 841–867, https://doi.org/10.5194/wes-9-841-2024, https://doi.org/10.5194/wes-9-841-2024, 2024
Short summary
Short summary
This review presents the current understanding of wind direction variability in the context of control-oriented modelling of wind turbines and wind farms in a manner suitable to a wide audience. Motivation comes from the significant and commonly seen yaw error of horizontal axis wind turbines, which carries substantial negative impacts on annual energy production and the levellised cost of wind energy. Gaps in the literature are identified, and the critical challenges in this area are discussed.
Paul Veers, Carlo L. Bottasso, Lance Manuel, Jonathan Naughton, Lucy Pao, Joshua Paquette, Amy Robertson, Michael Robinson, Shreyas Ananthan, Thanasis Barlas, Alessandro Bianchini, Henrik Bredmose, Sergio González Horcas, Jonathan Keller, Helge Aagaard Madsen, James Manwell, Patrick Moriarty, Stephen Nolet, and Jennifer Rinker
Wind Energ. Sci., 8, 1071–1131, https://doi.org/10.5194/wes-8-1071-2023, https://doi.org/10.5194/wes-8-1071-2023, 2023
Short summary
Short summary
Critical unknowns in the design, manufacturing, and operation of future wind turbine and wind plant systems are articulated, and key research activities are recommended.
Tuhfe Göçmen, Filippo Campagnolo, Thomas Duc, Irene Eguinoa, Søren Juhl Andersen, Vlaho Petrović, Lejla Imširović, Robert Braunbehrens, Jaime Liew, Mads Baungaard, Maarten Paul van der Laan, Guowei Qian, Maria Aparicio-Sanchez, Rubén González-Lope, Vinit V. Dighe, Marcus Becker, Maarten J. van den Broek, Jan-Willem van Wingerden, Adam Stock, Matthew Cole, Renzo Ruisi, Ervin Bossanyi, Niklas Requate, Simon Strnad, Jonas Schmidt, Lukas Vollmer, Ishaan Sood, and Johan Meyers
Wind Energ. Sci., 7, 1791–1825, https://doi.org/10.5194/wes-7-1791-2022, https://doi.org/10.5194/wes-7-1791-2022, 2022
Short summary
Short summary
The FarmConners benchmark is the first of its kind to bring a wide variety of data sets, control settings, and model complexities for the (initial) assessment of wind farm flow control benefits. Here we present the first part of the benchmark results for three blind tests with large-scale rotors and 11 participating models in total, via direct power comparisons at the turbines as well as the observed or estimated power gain at the wind farm level under wake steering control strategy.
Edward Hart, Elisha de Mello, and Rob Dwyer-Joyce
Wind Energ. Sci., 7, 1533–1550, https://doi.org/10.5194/wes-7-1533-2022, https://doi.org/10.5194/wes-7-1533-2022, 2022
Short summary
Short summary
This paper is the second in a two-part study on lubrication in wind turbine main bearings. Investigations are conducted concerning lubrication in the double-row spherical roller main bearing of a 1.5 MW wind turbine. This includes effects relating to temperature, starvation, grease-thickener interactions and possible non-steady EHL effects. Results predict that the modelled main bearing would be expected to operate under mixed lubrication conditions for a non-negligible proportion of its life.
Edward Hart, Elisha de Mello, and Rob Dwyer-Joyce
Wind Energ. Sci., 7, 1021–1042, https://doi.org/10.5194/wes-7-1021-2022, https://doi.org/10.5194/wes-7-1021-2022, 2022
Short summary
Short summary
This work provides an accessible introduction to elastohydrodynamic lubrication theory as a precursor to analysis of lubrication in a wind turbine main bearing. Fundamental concepts, derivations and formulas are presented, followed by the more advanced topics of starvation, non-steady effects, surface roughness interactions and grease lubrication.
Amir R. Nejad, Jonathan Keller, Yi Guo, Shawn Sheng, Henk Polinder, Simon Watson, Jianning Dong, Zian Qin, Amir Ebrahimi, Ralf Schelenz, Francisco Gutiérrez Guzmán, Daniel Cornel, Reza Golafshan, Georg Jacobs, Bart Blockmans, Jelle Bosmans, Bert Pluymers, James Carroll, Sofia Koukoura, Edward Hart, Alasdair McDonald, Anand Natarajan, Jone Torsvik, Farid K. Moghadam, Pieter-Jan Daems, Timothy Verstraeten, Cédric Peeters, and Jan Helsen
Wind Energ. Sci., 7, 387–411, https://doi.org/10.5194/wes-7-387-2022, https://doi.org/10.5194/wes-7-387-2022, 2022
Short summary
Short summary
This paper presents the state-of-the-art technologies and development trends of wind turbine drivetrains – the energy conversion systems transferring the kinetic energy of the wind to electrical energy – in different stages of their life cycle: design, manufacturing, installation, operation, lifetime extension, decommissioning and recycling. The main aim of this article is to review the drivetrain technology development as well as to identify future challenges and research gaps.
James Stirling, Edward Hart, and Abbas Kazemi Amiri
Wind Energ. Sci., 6, 15–31, https://doi.org/10.5194/wes-6-15-2021, https://doi.org/10.5194/wes-6-15-2021, 2021
Short summary
Short summary
This paper considers the modelling of wind turbine main bearings using analytical models. The validity of simplified analytical representations is explored by comparing main-bearing force reactions with those obtained from higher-fidelity 3D finite-element models. Results indicate that good agreement can be achieved between the analytical and 3D models in the case of both non-moment-reacting (such as for a spherical roller bearing) and moment-reacting (such as a tapered roller bearing) set-ups.
Edward Hart, Benjamin Clarke, Gary Nicholas, Abbas Kazemi Amiri, James Stirling, James Carroll, Rob Dwyer-Joyce, Alasdair McDonald, and Hui Long
Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, https://doi.org/10.5194/wes-5-105-2020, 2020
Short summary
Short summary
This paper presents a review of existing theory and practice relating to main bearings for wind turbines. Topics covered include wind conditions and resulting rotor loads, main-bearing models, damage mechanisms and fault detection procedures.
Jonathan Keller, Yi Guo, Zhiwei Zhang, and Doug Lucas
Wind Energ. Sci., 3, 947–960, https://doi.org/10.5194/wes-3-947-2018, https://doi.org/10.5194/wes-3-947-2018, 2018
Short summary
Short summary
The US Department of Energy's National Renewable Energy Laboratory (NREL) and industry partners successfully demonstrated a new gearbox design using preloaded tapered roller bearings in the planetary section. The new gearbox design demonstrated improved planetary load-sharing characteristics in the presence of rotor pitch and yaw moments, resulting in a predicted gearbox lifetime that is 3.5 times greater than the previous conventional design with cylindrical roller bearings.
Related subject area
Thematic area: Wind technologies | Topic: Design concepts and methods for plants, turbines, and components
Semi-analytical methodology for fretting wear evaluation of unlubricated pitch bearing raceways under operative and non-operative periods
Effect of blade inclination angle for straight-bladed vertical-axis wind turbines
Full-scale wind turbine performance assessment: a customised, sensor-augmented aeroelastic modelling approach
Challenges in detecting wind turbine power loss: the effects of blade erosion, turbulence, and time averaging
Identification of operational deflection shapes of a wind turbine gearbox using fiber-optic strain sensors on a serial production end-of-line test bench
One-to-one aeroservoelastic validation of operational loads and performance of a 2.8 MW wind turbine model in OpenFAST
Identification of electro-mechanical interactions in wind turbines
A sensitivity-based estimation method for investigating control co-design relevance
Validation of aeroelastic dynamic model of active trailing edge flap system tested on a 4.3 MW wind turbine
Probabilistic cost modeling as a basis for optimizing the inspection and maintenance of support structures in offshore wind farms
Mesoscale modelling of North Sea wind resources with COSMO-CLM: model evaluation and impact assessment of future wind farm characteristics on cluster-scale wake losses
Gradient-based wind farm layout optimization with inclusion and exclusion zones
A novel techno-economical layout optimization tool for floating wind farm design
Hybrid-Lambda: a low-specific-rating rotor concept for offshore wind turbines
Speeding up large-wind-farm layout optimization using gradients, parallelization, and a heuristic algorithm for the initial layout
Nonlinear vibration characteristics of virtual mass systems for wind turbine blade fatigue testing
Extreme wind turbine response extrapolation with the Gaussian mixture model
The effect of site-specific wind conditions and individual pitch control on wear of blade bearings
A neighborhood search integer programming approach for wind farm layout optimization
Enabling control co-design of the next generation of wind power plants
Offshore wind farm optimisation: a comparison of performance between regular and irregular wind turbine layouts
A data-driven reduced-order model for rotor optimization
Grand challenges in the design, manufacture, and operation of future wind turbine systems
Computational fluid dynamics (CFD) modeling of actual eroded wind turbine blades
Grand Challenges: wind energy research needs for a global energy transition
Current status and grand challenges for small wind turbine technology
CFD-based curved tip shape design for wind turbine blades
David Cubillas, Mireia Olave, Iñigo Llavori, Ibai Ulacia, Jon Larrañaga, Aitor Zurutuza, and Arkaitz Lopez
Wind Energ. Sci., 10, 401–415, https://doi.org/10.5194/wes-10-401-2025, https://doi.org/10.5194/wes-10-401-2025, 2025
Short summary
Short summary
A methodology for evaluating fretting in wind turbine pitch bearing raceways is presented, and a case study is evaluated. The methodology considers the coupled effects of radial fretting and rotational fretting. As result, critical locations based on the dissipated energy are identified for the different wind speeds and the contributions of operational and non-operational times, as well as the prediction of damage shapes on the raceway for both cases, are evaluated independently and compared.
Laurence Morgan, Abbas Kazemi Amiri, William Leithead, and James Carroll
Wind Energ. Sci., 10, 381–399, https://doi.org/10.5194/wes-10-381-2025, https://doi.org/10.5194/wes-10-381-2025, 2025
Short summary
Short summary
This paper presents a systematic study of the effect of blade inclination angle, chord distribution, and blade length on vertical-axis wind turbine performance. It shows that, for rotors of identical power production, both blade volume and rotor torque can be significantly reduced through the use of aerodynamically optimised inclined rotor blades. This demonstrates the potential of vertical rotors to reduce the cost of energy for offshore wind when compared to horizontal rotors.
Tahir H. Malik and Christian Bak
Wind Energ. Sci., 10, 269–291, https://doi.org/10.5194/wes-10-269-2025, https://doi.org/10.5194/wes-10-269-2025, 2025
Short summary
Short summary
This research integrates custom sensors into wind turbine simulation models for improved performance monitoring utilising a turbine performance integral (TPI) method developed here. Real-world data validation demonstrates that appropriate sensor selection improves wind turbine performance monitoring. This approach addresses the need for precise performance assessments in the evolving wind energy sector, ultimately promoting sustainability and efficiency.
Tahir H. Malik and Christian Bak
Wind Energ. Sci., 10, 227–243, https://doi.org/10.5194/wes-10-227-2025, https://doi.org/10.5194/wes-10-227-2025, 2025
Short summary
Short summary
This study investigates how wind turbine blades damaged by erosion, along with changing wind conditions, affect power output. Even minor blade damage can lead to significant energy losses, especially in turbulent winds. Using simulations, it was discovered that standard power data analysis methods, including time averaging, can hide these losses. This research highlights the need for better blade damage detection and careful wind data analysis to optimise wind farm performance.
Unai Gutierrez Santiago, Aemilius A. W. van Vondelen, Alfredo Fernández Sisón, Henk Polinder, and Jan-Willem van Wingerden
Wind Energ. Sci., 10, 207–225, https://doi.org/10.5194/wes-10-207-2025, https://doi.org/10.5194/wes-10-207-2025, 2025
Short summary
Short summary
Knowing the loads applied to wind turbine gearboxes throughout their service life is becoming increasingly important as maintaining reliability with higher torque density demands is proving to be challenging. Operational deflection shapes identified from fiber-optic strain measurements have enabled the estimation of input torque, improving the assessment of the consumed life. Tracking operational deflection shapes recursively over time can potentially be used as an indicator of fault detection.
Kenneth Brown, Pietro Bortolotti, Emmanuel Branlard, Mayank Chetan, Scott Dana, Nathaniel deVelder, Paula Doubrawa, Nicholas Hamilton, Hristo Ivanov, Jason Jonkman, Christopher Kelley, and Daniel Zalkind
Wind Energ. Sci., 9, 1791–1810, https://doi.org/10.5194/wes-9-1791-2024, https://doi.org/10.5194/wes-9-1791-2024, 2024
Short summary
Short summary
This paper presents a study of the popular wind turbine design tool OpenFAST. We compare simulation results to measurements obtained from a 2.8 MW land-based wind turbine. Measured wind conditions were used to generate turbulent flow fields through several techniques. We show that successful validation of the tool is not strongly dependent on the inflow generation technique used for mean quantities of interest. The type of inflow assimilation method has a larger effect on fatigue quantities.
Fiona Dominique Lüdecke, Martin Schmid, and Po Wen Cheng
Wind Energ. Sci., 9, 1527–1545, https://doi.org/10.5194/wes-9-1527-2024, https://doi.org/10.5194/wes-9-1527-2024, 2024
Short summary
Short summary
Large direct-drive wind turbines, with a multi-megawatt power rating, face design challenges. Moving towards a more system-oriented design approach could potentially reduce mass and costs. Exploiting the full design space, though, may invoke interaction mechanisms, which have been neglected in the past. Based on coupled simulations, this work derives a better understanding of the electro-mechanical interaction mechanisms and identifies potential for design relevance.
Jenna Iori, Carlo Luigi Bottasso, and Michael Kenneth McWilliam
Wind Energ. Sci., 9, 1289–1304, https://doi.org/10.5194/wes-9-1289-2024, https://doi.org/10.5194/wes-9-1289-2024, 2024
Short summary
Short summary
The controller of a wind turbine has an important role in regulating power production and avoiding structural failure. However, it is often designed after the rest of the turbine, and thus its potential is not fully exploited. An alternative is to design the structure and the controller simultaneously. This work develops a method to identify if a given turbine design can benefit from this new simultaneous design process. For example, a higher and cheaper turbine tower can be built this way.
Andrea Gamberini, Thanasis Barlas, Alejandro Gomez Gonzalez, and Helge Aagaard Madsen
Wind Energ. Sci., 9, 1229–1249, https://doi.org/10.5194/wes-9-1229-2024, https://doi.org/10.5194/wes-9-1229-2024, 2024
Short summary
Short summary
Movable surfaces on wind turbine (WT) blades, called active flaps, can reduce the cost of wind energy. However, they still need extensive testing. This study shows that the computer model used to design a WT with flaps aligns well with measurements obtained from a 3month test on a commercial WT featuring a prototype flap. Particularly during flap actuation, there were minimal differences between simulated and measured data. These findings assure the reliability of WT designs incorporating flaps.
Muhammad Farhan, Ronald Schneider, Sebastian Thöns, and Max Gündel
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2023-176, https://doi.org/10.5194/wes-2023-176, 2024
Revised manuscript accepted for WES
Short summary
Short summary
This paper formulates and applies a probabilistic cost model to support the operational management of offshore wind farms. It provides the decision-theoretical basis for the optimization of I&M regimes with an emphasis on integrating the probabilistic cost model into the decision analysis. The proposed probabilistic cost model is then applied in a numerical example and a value of information analysis is performed to quantify the cost effectiveness of the identified optimal I&M strategy.
Ruben Borgers, Marieke Dirksen, Ine L. Wijnant, Andrew Stepek, Ad Stoffelen, Naveed Akhtar, Jérôme Neirynck, Jonas Van de Walle, Johan Meyers, and Nicole P. M. van Lipzig
Wind Energ. Sci., 9, 697–719, https://doi.org/10.5194/wes-9-697-2024, https://doi.org/10.5194/wes-9-697-2024, 2024
Short summary
Short summary
Wind farms at sea are becoming more densely clustered, which means that next to individual wind turbines interfering with each other in a single wind farm also interference between wind farms becomes important. Using a climate model, this study shows that the efficiency of wind farm clusters and the interference between the wind farms in the cluster depend strongly on the properties of the individual wind farms and are also highly sensitive to the spacing between the wind farms.
Javier Criado Risco, Rafael Valotta Rodrigues, Mikkel Friis-Møller, Julian Quick, Mads Mølgaard Pedersen, and Pierre-Elouan Réthoré
Wind Energ. Sci., 9, 585–600, https://doi.org/10.5194/wes-9-585-2024, https://doi.org/10.5194/wes-9-585-2024, 2024
Short summary
Short summary
Wind energy developers frequently have to face some spatial restrictions at the time of designing a new wind farm due to different reasons, such as the existence of protected natural areas around the wind farm location, fishing routes, and the presence of buildings. Wind farm design has to account for these restricted areas, but sometimes this is not straightforward to achieve. We have developed a methodology that allows for different inclusion and exclusion areas in the optimization framework.
Amalia Ida Hietanen, Thor Heine Snedker, Katherine Dykes, and Ilmas Bayati
Wind Energ. Sci., 9, 417–438, https://doi.org/10.5194/wes-9-417-2024, https://doi.org/10.5194/wes-9-417-2024, 2024
Short summary
Short summary
The layout of a floating offshore wind farm was optimized to maximize the relative net present value (NPV). By modeling power generation, losses, inter-array cables, anchors and operational costs, an increase of EUR 34.5 million in relative NPV compared to grid-based layouts was achieved. A sensitivity analysis was conducted to examine the impact of economic factors, providing valuable insights. This study contributes to enhancing the efficiency and cost-effectiveness of floating wind farms.
Daniel Ribnitzky, Frederik Berger, Vlaho Petrović, and Martin Kühn
Wind Energ. Sci., 9, 359–383, https://doi.org/10.5194/wes-9-359-2024, https://doi.org/10.5194/wes-9-359-2024, 2024
Short summary
Short summary
This paper provides an innovative blade design methodology for offshore wind turbines with very large rotors compared to their rated power, which are tailored for an increased power feed-in at low wind speeds. Rather than designing the blade for a single optimized operational point, we include the application of peak shaving in the design process and introduce a design for two tip speed ratios. We describe how enlargement of the rotor diameter can be realized to improve the value of wind power.
Rafael Valotta Rodrigues, Mads Mølgaard Pedersen, Jens Peter Schøler, Julian Quick, and Pierre-Elouan Réthoré
Wind Energ. Sci., 9, 321–341, https://doi.org/10.5194/wes-9-321-2024, https://doi.org/10.5194/wes-9-321-2024, 2024
Short summary
Short summary
The use of wind energy has been growing over the last few decades, and further increase is predicted. As the wind energy industry is starting to consider larger wind farms, the existing numerical methods for analysis of small and medium wind farms need to be improved. In this article, we have explored different strategies to tackle the problem in a feasible and timely way. The final product is a set of recommendations when carrying out trade-off analysis on large wind farms.
Aiguo Zhou, Jinlei Shi, Tao Dong, Yi Ma, and Zhenhui Weng
Wind Energ. Sci., 9, 49–64, https://doi.org/10.5194/wes-9-49-2024, https://doi.org/10.5194/wes-9-49-2024, 2024
Short summary
Short summary
This paper explores the nonlinear influence of the virtual mass mechanism on the test system in blade biaxial tests. The blade theory and simulation model are established to reveal the nonlinear amplitude–frequency characteristics of the blade-virtual-mass system. Increasing the amplitude of the blade or decreasing the seesaw length will lower the resonance frequency and load of the system. The virtual mass also affects the blade biaxial trajectory.
Xiaodong Zhang and Nikolay Dimitrov
Wind Energ. Sci., 8, 1613–1623, https://doi.org/10.5194/wes-8-1613-2023, https://doi.org/10.5194/wes-8-1613-2023, 2023
Short summary
Short summary
Wind turbine extreme response estimation based on statistical extrapolation necessitates using a small number of simulations to calculate a low exceedance probability. This is a challenging task especially if we require small prediction error. We propose the use of a Gaussian mixture model as it is capable of estimating a low exceedance probability with minor bias error, even with limited simulation data, having flexibility in modeling the distributions of varying response variables.
Arne Bartschat, Karsten Behnke, and Matthias Stammler
Wind Energ. Sci., 8, 1495–1510, https://doi.org/10.5194/wes-8-1495-2023, https://doi.org/10.5194/wes-8-1495-2023, 2023
Short summary
Short summary
Blade bearings are among the most stressed and challenging components of a wind turbine. Experimental investigations using different test rigs and real-size blade bearings have been able to show that rather short time intervals of only several hours of turbine operation can cause wear damage on the raceways of blade bearings. The proposed methods can be used to assess wear-critical operation conditions and to validate control strategies as well as lubricants for the application.
Juan-Andrés Pérez-Rúa, Mathias Stolpe, and Nicolaos Antonio Cutululis
Wind Energ. Sci., 8, 1453–1473, https://doi.org/10.5194/wes-8-1453-2023, https://doi.org/10.5194/wes-8-1453-2023, 2023
Short summary
Short summary
With the challenges of ensuring secure energy supplies and meeting climate targets, wind energy is on course to become the cornerstone of decarbonized energy systems. This work proposes a new method to optimize wind farms by means of smartly placing wind turbines within a given project area, leading to more green-energy generation. This method performs satisfactorily compared to state-of-the-art approaches in terms of the resultant annual energy production and other high-level metrics.
Andrew P. J. Stanley, Christopher J. Bay, and Paul Fleming
Wind Energ. Sci., 8, 1341–1350, https://doi.org/10.5194/wes-8-1341-2023, https://doi.org/10.5194/wes-8-1341-2023, 2023
Short summary
Short summary
Better wind farms can be built by simultaneously optimizing turbine locations and control, which is currently impossible or extremely challenging because of the size of the problem. The authors present a method to determine optimal wind farm control as a function of the turbine locations, which enables turbine layout and control to be optimized together by drastically reducing the size of the problem. In an example, a wind farm's performance improves by 0.8 % when optimized with the new method.
Maaike Sickler, Bart Ummels, Michiel Zaaijer, Roland Schmehl, and Katherine Dykes
Wind Energ. Sci., 8, 1225–1233, https://doi.org/10.5194/wes-8-1225-2023, https://doi.org/10.5194/wes-8-1225-2023, 2023
Short summary
Short summary
This paper investigates the effect of wind farm layout on the performance of offshore wind farms. A regular farm layout is compared to optimised irregular layouts. The irregular layouts have higher annual energy production, and the power production is less sensitive to wind direction. However, turbine towers require thicker walls to counteract increased fatigue due to increased turbulence levels in the farm. The study shows that layout optimisation can be used to maintain high-yield performance.
Nicholas Peters, Christopher Silva, and John Ekaterinaris
Wind Energ. Sci., 8, 1201–1223, https://doi.org/10.5194/wes-8-1201-2023, https://doi.org/10.5194/wes-8-1201-2023, 2023
Short summary
Short summary
Wind turbines have increasingly been leveraged as a viable approach for obtaining renewable energy. As such, it is essential that engineers have a high-fidelity, low-cost approach to modeling rotor load distributions. In this study, such an approach is proposed. This modeling approach was shown to make high-fidelity predictions at a low computational cost for rotor distributed-pressure loads as rotor geometry varied, allowing for an optimization of the rotor to be completed.
Paul Veers, Carlo L. Bottasso, Lance Manuel, Jonathan Naughton, Lucy Pao, Joshua Paquette, Amy Robertson, Michael Robinson, Shreyas Ananthan, Thanasis Barlas, Alessandro Bianchini, Henrik Bredmose, Sergio González Horcas, Jonathan Keller, Helge Aagaard Madsen, James Manwell, Patrick Moriarty, Stephen Nolet, and Jennifer Rinker
Wind Energ. Sci., 8, 1071–1131, https://doi.org/10.5194/wes-8-1071-2023, https://doi.org/10.5194/wes-8-1071-2023, 2023
Short summary
Short summary
Critical unknowns in the design, manufacturing, and operation of future wind turbine and wind plant systems are articulated, and key research activities are recommended.
Kisorthman Vimalakanthan, Harald van der Mijle Meijer, Iana Bakhmet, and Gerard Schepers
Wind Energ. Sci., 8, 41–69, https://doi.org/10.5194/wes-8-41-2023, https://doi.org/10.5194/wes-8-41-2023, 2023
Short summary
Short summary
Leading edge erosion (LEE) is one of the most critical degradation mechanisms that occur with wind turbine blades. A detailed understanding of the LEE process and the impact on aerodynamic performance due to the damaged leading edge is required to optimize blade maintenance. Providing accurate modeling tools is therefore essential. This novel study assesses CFD approaches for modeling high-resolution scanned LE surfaces from an actual blade with LEE damages.
Paul Veers, Katherine Dykes, Sukanta Basu, Alessandro Bianchini, Andrew Clifton, Peter Green, Hannele Holttinen, Lena Kitzing, Branko Kosovic, Julie K. Lundquist, Johan Meyers, Mark O'Malley, William J. Shaw, and Bethany Straw
Wind Energ. Sci., 7, 2491–2496, https://doi.org/10.5194/wes-7-2491-2022, https://doi.org/10.5194/wes-7-2491-2022, 2022
Short summary
Short summary
Wind energy will play a central role in the transition of our energy system to a carbon-free future. However, many underlying scientific issues remain to be resolved before wind can be deployed in the locations and applications needed for such large-scale ambitions. The Grand Challenges are the gaps in the science left behind during the rapid growth of wind energy. This article explains the breadth of the unfinished business and introduces 10 articles that detail the research needs.
Alessandro Bianchini, Galih Bangga, Ian Baring-Gould, Alessandro Croce, José Ignacio Cruz, Rick Damiani, Gareth Erfort, Carlos Simao Ferreira, David Infield, Christian Navid Nayeri, George Pechlivanoglou, Mark Runacres, Gerard Schepers, Brent Summerville, David Wood, and Alice Orrell
Wind Energ. Sci., 7, 2003–2037, https://doi.org/10.5194/wes-7-2003-2022, https://doi.org/10.5194/wes-7-2003-2022, 2022
Short summary
Short summary
The paper is part of the Grand Challenges Papers for Wind Energy. It provides a status of small wind turbine technology in terms of technical maturity, diffusion, and cost. Then, five grand challenges that are thought to be key to fostering the development of the technology are proposed. To tackle these challenges, a series of unknowns and gaps are first identified and discussed. Improvement areas are highlighted, within which 10 key enabling actions are finally proposed to the wind community.
Mads H. Aa. Madsen, Frederik Zahle, Sergio González Horcas, Thanasis K. Barlas, and Niels N. Sørensen
Wind Energ. Sci., 7, 1471–1501, https://doi.org/10.5194/wes-7-1471-2022, https://doi.org/10.5194/wes-7-1471-2022, 2022
Short summary
Short summary
This work presents a shape optimization framework based on computational fluid dynamics. The design framework is used to optimize wind turbine blade tips for maximum power increase while avoiding that extra loading is incurred. The final results are shown to align well with related literature. The resulting tip shape could be mounted on already installed wind turbines as a sleeve-like solution or be conceived as part of a modular blade with tips designed for site-specific conditions.
Cited articles
Barter, G. E., Robertson, A., and Musial, W.: A systems engineering vision for
floating offshore wind cost optimization, Renewable Energy Focus, 34, 1–16,
https://doi.org/10.1016/j.ref.2020.03.002, 2020. a
Bergua, R., Keller, J., Bankestrom, O., Dunn, M., Guo, Y., Key, A., and Young,
E.: Up-tower investigation of main bearing cage slip and loads,
https://www.nrel.gov/docs/fy22osti/81240.pdf (last access: 11 March 2022), 2021. a
Bossanyi, E. A.: Individual blade pitch control for load reduction, Wind
Energy, 6, 119–128, 2003. a
Burton, T., Jenkins, N., Sharpe, D., and Bossanyi, E.: Wind Energy Handbook, 2nd Edition, John Wiley & Sons ltd, Chichester, ISBN 978-0-470-69975-1, 2001. a
Cardaun, M., Roscher, B., Schelenz, R., and Jacobs, G.: Analysis of
Wind-Turbine Main Bearing Loads Due to Constant Yaw Misalignments over a 20
Years Timespan, Energies, 12, 1768, https://doi.org/10.3390/en12091768, 2019. a, b
Chatzopoulos, A.-P.: Full envelope wind turbine controller design for power
regulation and tower load reduction, PhD thesis, University of Strathclyde,
https://doi.org/10.48730/xcmh-3713, 2011. a
Fleming, P., Annoni, J., Shah, J. J., Wang, L., Ananthan, S., Zhang, Z., Hutchings, K., Wang, P., Chen, W., and Chen, L.: Field test of wake steering at an offshore wind farm, Wind Energ. Sci., 2, 229–239, https://doi.org/10.5194/wes-2-229-2017, 2017. a
Gaertner, E., Rinker, J., Sethuraman, L., Zahle, F., Anderson, B., Barter, G.,
Abbas, N., Meng, F., Bortolotti, P., Skrzypinski, W., Scott, G., Feil, R.,
Bredmose, H., Dykes, K., Shields, M., Allen, C., and Viselli, A.: Definition
of the IEA 15-megawatt offshore reference wind turbine,
https://www.nrel.gov/docs/fy20osti/75698.pdf (last access: 1 June 2022), 2020. a
GE: Haliade 150-6MW offshore wind turbine,
https://www.ge.com/renewableenergy/wind-energy/offshore-wind/offshore-turbine-haliade-150-6mw (last access: 13 May 2022),
2021. a
Gould, B. and Burris, D.: Effects of wind shear on wind turbine rotor loads and
planetary bearing reliability, Wind Energy, 19, 1011–1021, 2016. a
Guo, Y., van Dam, J., Bergua, R., Jové, J., and Campbell, J.: Improving Wind
Turbine Drivetrain Reliability Using a Combined Experimental, Computational,
and Analytical Approach, in: ASME 2014 International Design Engineering
Technical Conferences & Computers and Information in Engineering Conference
(IDETC/CIE 2014), NREL/CP-5000-61683,
https://www.nrel.gov/docs/fy15osti/61683.pdf (last access: 1 June 2022), 2014. a, b
Guo, Y., Parsons, T., Dykes, K., and King, R. N.: A systems engineering
analysis of three-point and four-point wind turbine drivetrain
configurations, Wind Energy, 20, 537–550, 2017. a
Guo, Y., Bankestrom, O., Bergua, R., Keller, J., and Dunn, M.: Investigation of
main bearing operating conditions in a three-point mount wind turbine
drivetrain, Forschung im Ingenieurwesen, 1–11, https://doi.org/10.1007/s10010-021-00477-8, 2021. a, b
Hart, E., Turnbull, A., Feuchtwang, J., McMillan, D., Golysheva, E., and
Elliott, R.: Wind turbine main-bearing loading and wind field
characteristics, Wiley Wind Energy, 22, 1534–1547, https://doi.org/10.1002/we.2386,
2019. a, b, c
Hart, E., Clarke, B., Nicholas, G., Kazemi Amiri, A., Stirling, J., Carroll, J., Dwyer-Joyce, R., McDonald, A., and Long, H.: A review of wind turbine main bearings: design, operation, modelling, damage mechanisms and fault detection, Wind Energ. Sci., 5, 105–124, https://doi.org/10.5194/wes-5-105-2020, 2020. a, b, c, d, e
Jamieson, P. and Hassan, G.: Innovation in wind turbine design, vol. 2, Wiley
Online Library, 2011. a
Jenkins, N., Burton, T. L., Bossanyi, E., Sharpe, D., and Graham, M. (Eds.): Wind
Energy Handbook, John Wiley & Sons, ISBN 9781119451099, 2021. a
Jonkman, J., Butterfield, S., Musial, W., and Scott, G.: Definition of a 5-MW
reference wind turbine for offshore system development, Tech. rep., National
Renewable Energy Laboratory (NREL), Golden, CO (United States),
https://www.nrel.gov/docs/fy09osti/38060.pdf (last access: 21 April 2022), 2009. a, b
Keller, J., Sheng, S., Cotrell, J., and Greco, A.: Wind turbine drivetrain
reliability collaborative workshop: a recap, Tech. rep., U.S. Department of
Energy, https://www.nrel.gov/docs/fy16osti/66593.pdf (last access: 10 April 2022), 2016. a
Kelley, N. D. and Jonkman, B. J.: Overview of the TurbSim stochastic inflow
turbulence simulator, Tech. rep., National Renewable Energy Laboratory
(NREL), Golden, CO (United States), https://www.nrel.gov/docs/fy05osti/36971.pdf
(last access: 1 June 2022), 2005. a
Kock, S., Jacobs, G., and Bosse, D.: Determination of Wind Turbine Main Bearing
Load Distribution, IOP Conf. Ser.-J. Phys., 1222, 012030,
https://doi.org/10.1088/1742-6596/1222/1/012030, 2019. a
Lavely, A. W.: Effects of daytime atmospheric boundary layer turbulence on the
generation of nonsteady wind turbine loadings and predictive accuracy of
lower order models, The Pennsylvania State University, https://etda.libraries.psu.edu/catalog/13830awl5173
(last access: 1 June 2022), 2017. a, b, c
Leithead, W. and Stock, A.: UK wind energy technologies – Wind Turbine
Control, in: UK Wind Energy Technologies, edited by: Hogg, S. and Crabtree,
C., chap. 6, Routledge, 1 edn., 219–258, https://doi.org/10.4324/9781315681382,
2016. a, b
Leithead, W. E. and Dominguez, S.: Coordinated control design for wind turbine
control systems, in: Proceedings of European Wind Energy Conference and
Exhibition, Athens, Greece, 27 February 2006–2 March 2006, vol. 27, https://www.researchgate.net/publication/267683408_Coordinated_Control_Design_for_Wind_Turbine_Control_Systems
(last access: 1 June 2022), 2006. a
Mann, J.: Wind field simulation, Probabilist. Eng. Mech., 13,
269–282, https://doi.org/10.1016/S0266-8920(97)00036-2, 1998. a
Murphy, P., Lundquist, J. K., and Fleming, P.: How wind speed shear and directional veer affect the power production of a megawatt-scale operational wind turbine, Wind Energ. Sci., 5, 1169–1190, https://doi.org/10.5194/wes-5-1169-2020, 2020. a
Nandi, T., Herrig, A., and Brasseur, J.: Non-steady wind turbine response to
daytime atmospheric turbulence, Philos. T. Roy.
Soc. A, 375, 20160103, https://doi.org/10.1098/rsta.2016.0103,
2017. a, b
Nejad, A. R. and Torsvik, J.: Drivetrains on floating offshore wind turbines: lessons learned over the last 10 years, Forsch. Ingenieurw., 85, 335–343, https://doi.org/10.1007/s10010-021-00469-8, 2021. a
Nejad, A. R., Keller, J., Guo, Y., Sheng, S., Polinder, H., Watson, S., Dong, J., Qin, Z., Ebrahimi, A., Schelenz, R., Gutiérrez Guzmán, F., Cornel, D., Golafshan, R., Jacobs, G., Blockmans, B., Bosmans, J., Pluymers, B., Carroll, J., Koukoura, S., Hart, E., McDonald, A., Natarajan, A., Torsvik, J., Moghadam, F. K., Daems, P.-J., Verstraeten, T., Peeters, C., and Helsen, J.: Wind turbine drivetrains: state-of-the-art technologies and future development trends, Wind Energ. Sci., 7, 387–411, https://doi.org/10.5194/wes-7-387-2022, 2022. a, b, c
Pedersen, J., Juncker, K., and Randewijk, P. J.: Lifetime Estimation of
Semiconducting Components in 8MW Wind Turbine Generators with “Power
Boost” Functionality, in: 2020 55th International Universities Power
Engineering Conference (UPEC), 1–6, IEEE, https://doi.org/10.1109/UPEC49904.2020.9209801, 2020. a
Sethuraman, L., Guo, Y., and Sheng, S.: Main bearing dynamics in three point
suspension drivetrains for wind turbines, American Wind Energy Association
WindPower Conference and Exhibition, https://www.nrel.gov/docs/fy15osti/64311.pdf
(last access: 1 June 2022), 2015.
a
Stirling, J., Hart, E., and Kazemi Amiri, A.: Constructing fast and representative analytical models of wind turbine main bearings, Wind Energ. Sci., 6, 15–31, https://doi.org/10.5194/wes-6-15-2021, 2021. a, b, c, d
Thompson, D. W.: Mitigating size related limitations in wind turbine control,
PhD thesis, University of Strathclyde, https://doi.org/10.48730/ej6k-8507, 2018. a, b
Torsvik, J., Nejad, A. R., and Pedersen, E.: Main bearings in large offshore
wind turbines: development trends, design and analysis requirements, J. Phys.-Conf. Ser., 1037, 042020, https://doi.org/10.1088/1742-6596/1037/4/042020,
2018. a
van Dam, J.: Advanced Wind Turbine Drivetrain Topology for Improving System
Reliability, NREL/TP-5000-77552, Tech. rep., National Renewable Energy
Laboratory (NREL),
https://www.nrel.gov/docs/fy20osti/77552.pdf (last access: 1 June 2022), 2020. a
Vijayakumar, G. and Brasseur, J.: Blade-resolved modeling with
fluid–structure interaction, chap. 2, edited by: Veers, P. S., Wind Energy
Modeling and Simulation, Volume 1: Atmosphere and Plant, Tech. rep., National
Renewable Energy Laboratory (NREL), Golden, CO (United States), https://doi.org/10.1049/PBPO125F_ch2, 2019. a
Wang, S., Nejad, A. R., Bachynski, E. E., and Moan, T.: Effects of bedplate
flexibility on drivetrain dynamics: Case study of a 10 MW spar type floating
wind turbine, Renew. Energ., 161, 808–824,
https://doi.org/10.1016/j.renene.2020.07.148, 2020. a
Zhang, H., Shi, W., Liu, G., and Chen, Z.: A Method to Solve the Stiffness of
Double-Row Tapered Roller Bearing, Math. Probl. Eng., 2019, 1857931, https://doi.org/10.1155/2019/1857931,
2019. a, b
Zheng, J., Ji, J., Yin, S., and Tong, V. C.: The load distribution of the main
shaft bearing considering combined load and misalignment in a floating
direct-drive wind turbine, in: E3S web of conferences, vol. 64, 07009, EDP
Sciences, https://doi.org/10.1051/e3sconf/20186407009, 2018. a
Zheng, J., Ji, J., Yin, S., and Tong, V.-C.: Fatigue life analysis of
double-row tapered roller bearing in a modern wind turbine under oscillating
external load and speed, P. I. Mech.
Eng. C-J. Mech., 234,
3116–3130, 2020a. a
Zheng, J., Ji, J., Yin, S., and Tong, V.-C.: Internal loads and contact
pressure distributions on the main shaft bearing in a modern gearless wind
turbine, Tribol. Int., 141, 105960, https://doi.org/10.1016/j.triboint.2019.105960, 2020b. a
Short summary
We consider characteristics and drivers of loads experienced by wind turbine main bearings using simplified models of hub and main-bearing configurations. Influences of deterministic wind characteristics are investigated for 5, 7.5, and 10 MW turbine models. Load response to gusts and wind direction changes are also considered. Cubic load scaling is observed, veer is identified as an important driver of load fluctuations, and strong links between control and main-bearing load response are shown.
We consider characteristics and drivers of loads experienced by wind turbine main bearings using...
Altmetrics
Final-revised paper
Preprint