Articles | Volume 2, issue 2
https://doi.org/10.5194/wes-2-469-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/wes-2-469-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Brief communication: Structural monitoring for lifetime extension of offshore wind monopiles: can strain measurements at one level tell us everything?
Ramboll Wind, 20097 Hamburg, Germany
Department of Civil and Environmental Engineering, Norwegian
University of Science and Technology NTNU, 7491 Trondheim, Norway
Ursula Smolka
Ramboll Wind, 20097 Hamburg, Germany
Nicolai Cosack
Ramboll Wind, 20097 Hamburg, Germany
Michael Muskulus
Department of Civil and Environmental Engineering, Norwegian
University of Science and Technology NTNU, 7491 Trondheim, Norway
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Lars Einar S. Stieng and Michael Muskulus
Wind Energ. Sci., 5, 171–198, https://doi.org/10.5194/wes-5-171-2020, https://doi.org/10.5194/wes-5-171-2020, 2020
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We present a framework for reducing the cost of support structures for offshore wind turbines that takes into account the many uncertainties that go into the design process. The results demonstrate how an efficient new approach, tailored for support structure design, allows the state of the art for design without uncertainties to be used within a framework that does include these uncertainties. This allows more realistic, and less conservative, design methods
to be used for practical design.
Lars Einar S. Stieng and Michael Muskulus
Wind Energ. Sci., 3, 805–818, https://doi.org/10.5194/wes-3-805-2018, https://doi.org/10.5194/wes-3-805-2018, 2018
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This study was done in order to simplify the analysis needed for the assessment of safety criteria that offshore wind turbine support structures must satisfy. The work was done via simulations of the system and computations and analyses of the resulting data. The results show that the proposed methodology has great potential for simplifying the assessment procedure while retaining acceptable accuracy compared to the full analysis. There are several applications within both research and industry.
Sebastian Schafhirt and Michael Muskulus
Wind Energ. Sci., 3, 25–41, https://doi.org/10.5194/wes-3-25-2018, https://doi.org/10.5194/wes-3-25-2018, 2018
G. A. M. van Kuik, J. Peinke, R. Nijssen, D. Lekou, J. Mann, J. N. Sørensen, C. Ferreira, J. W. van Wingerden, D. Schlipf, P. Gebraad, H. Polinder, A. Abrahamsen, G. J. W. van Bussel, J. D. Sørensen, P. Tavner, C. L. Bottasso, M. Muskulus, D. Matha, H. J. Lindeboom, S. Degraer, O. Kramer, S. Lehnhoff, M. Sonnenschein, P. E. Sørensen, R. W. Künneke, P. E. Morthorst, and K. Skytte
Wind Energ. Sci., 1, 1–39, https://doi.org/10.5194/wes-1-1-2016, https://doi.org/10.5194/wes-1-1-2016, 2016
Related subject area
Offshore technology
A framework for simultaneous design of wind turbines and cable layout in offshore wind
Alignment of scanning lidars in offshore wind farms
Damping identification of offshore wind turbines using operational modal analysis: a review
FAST.Farm load validation for single wake situations at alpha ventus
Exploitation of the far-offshore wind energy resource by fleets of energy ships – Part 2: Updated ship design and cost of energy estimate
Revealing system variability in offshore service operations through systemic hazard analysis
Characterization of the unsteady aerodynamic response of a floating offshore wind turbine to surge motion
Characterisation of the offshore precipitation environment to help combat leading edge erosion of wind turbine blades
US East Coast synthetic aperture radar wind atlas for offshore wind energy
Brief communication: Nowcasting of precipitation for leading-edge-erosion-safe mode
Exploitation of the far-offshore wind energy resource by fleets of energy ships – Part 1: Energy ship design and performance
Analysing uncertainties in offshore wind farm power output using measure–correlate–predict methodologies
Exploitation of the far-offshore wind energy resource by fleets of energy ships. Part B. Cost of energy
Hurricane eyewall winds and structural response of wind turbines
Extending the life of wind turbine blade leading edges by reducing the tip speed during extreme precipitation events
Applications of satellite winds for the offshore wind farm site Anholt
Decoupled simulations of offshore wind turbines with reduced rotor loads and aerodynamic damping
Simulation of an offshore wind farm using fluid power for centralized electricity generation
Effect of foundation modelling on the fatigue lifetime of a monopile-based offshore wind turbine
Juan-Andrés Pérez-Rúa and Nicolaos Antonio Cutululis
Wind Energ. Sci., 7, 925–942, https://doi.org/10.5194/wes-7-925-2022, https://doi.org/10.5194/wes-7-925-2022, 2022
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Wind farms are becoming larger, and they are shaping up as one of the main drivers towards full green energy transition. Because of their massive proliferation, more and more attention is nowadays focused on optimal design of these power plants. We propose an optimization framework in order to contribute to further cost reductions, by simultaneously designing the wind turbines and cable layout. We show the capability of the framework to improve designs compared to the classic approach.
Andreas Rott, Jörge Schneemann, Frauke Theuer, Juan José Trujillo Quintero, and Martin Kühn
Wind Energ. Sci., 7, 283–297, https://doi.org/10.5194/wes-7-283-2022, https://doi.org/10.5194/wes-7-283-2022, 2022
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We present three methods that can determine the alignment of a lidar placed on the transition piece of an offshore wind turbine based on measurements with the instrument: a practical implementation of hard targeting for north alignment, a method called sea surface levelling to determine the levelling of the system from water surface measurements, and a model that can determine the dynamic levelling based on the operating status of the wind turbine.
Aemilius A. W. van Vondelen, Sachin T. Navalkar, Alexandros Iliopoulos, Daan C. van der Hoek, and Jan-Willem van Wingerden
Wind Energ. Sci., 7, 161–184, https://doi.org/10.5194/wes-7-161-2022, https://doi.org/10.5194/wes-7-161-2022, 2022
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The damping of an offshore wind turbine is a difficult physical quantity to predict, although it plays a major role in a cost-effective turbine design. This paper presents a review of all approaches that can be used for damping estimation directly from operational wind turbine data. As each use case is different, a novel suitability table is presented to enable the user to choose the most appropriate approach for the given availability and characteristics of measurement data.
Matthias Kretschmer, Jason Jonkman, Vasilis Pettas, and Po Wen Cheng
Wind Energ. Sci., 6, 1247–1262, https://doi.org/10.5194/wes-6-1247-2021, https://doi.org/10.5194/wes-6-1247-2021, 2021
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We perform a validation of the new simulation tool FAST.Farm for the prediction of power output and structural loads in single wake conditions with respect to measurement data from the offshore wind farm alpha ventus. With a new wake-added turbulence functionality added to FAST.Farm, good agreement between simulations and measurements is achieved for the considered quantities. We hereby give insights into load characteristics of an offshore wind turbine subjected to single wake conditions.
Aurélien Babarit, Félix Gorintin, Pierrick de Belizal, Antoine Neau, Giovanni Bordogna, and Jean-Christophe Gilloteaux
Wind Energ. Sci., 6, 1191–1204, https://doi.org/10.5194/wes-6-1191-2021, https://doi.org/10.5194/wes-6-1191-2021, 2021
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In this paper, a new energy system for the conversion of far-offshore wind energy into methanol is proposed, and the cost of energy is estimated. Results show that this system could produce approximately 70 000 t of methanol per annum at a cost comparable to that of methanol produced by offshore wind farms in the long term.
Romanas Puisa, Victor Bolbot, Andrew Newman, and Dracos Vassalos
Wind Energ. Sci., 6, 273–286, https://doi.org/10.5194/wes-6-273-2021, https://doi.org/10.5194/wes-6-273-2021, 2021
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The paper proposes a quantitative, non-probabilistic metric for the preliminary comparison of safety of windfarm service operation vessels (SOV) in typical phases of operation. The metric is used as a conditional proxy for the incident likelihood, conditioned upon the presence of similar resources (manpower, time, skills, knowledge, information, etc.) for risk management across compared operational phases.
Simone Mancini, Koen Boorsma, Marco Caboni, Marion Cormier, Thorsten Lutz, Paolo Schito, and Alberto Zasso
Wind Energ. Sci., 5, 1713–1730, https://doi.org/10.5194/wes-5-1713-2020, https://doi.org/10.5194/wes-5-1713-2020, 2020
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This work characterizes the unsteady aerodynamic response of a scaled version of a 10 MW floating wind turbine subjected to an imposed platform motion. The focus has been put on the simple yet significant motion along the wind's direction (surge). For this purpose, different state-of-the-art aerodynamic codes have been used, validating the outcomes with detailed wind tunnel experiments. This paper sheds light on floating-turbine unsteady aerodynamics for a more conscious controller design.
Robbie Herring, Kirsten Dyer, Paul Howkins, and Carwyn Ward
Wind Energ. Sci., 5, 1399–1409, https://doi.org/10.5194/wes-5-1399-2020, https://doi.org/10.5194/wes-5-1399-2020, 2020
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Leading edge erosion has developed into a significant problem for the offshore wind industry. It is important to understand the offshore precipitation environment to model and predict the onset of erosion and to design systems to protect against it. In this study, the offshore environment was characterised using up-to-date measuring techniques. A general offshore droplet size distribution that can be used to improve lifetime prediction techniques has been presented.
Tobias Ahsbahs, Galen Maclaurin, Caroline Draxl, Christopher R. Jackson, Frank Monaldo, and Merete Badger
Wind Energ. Sci., 5, 1191–1210, https://doi.org/10.5194/wes-5-1191-2020, https://doi.org/10.5194/wes-5-1191-2020, 2020
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Before constructing wind farms we need to know how much energy they will produce. This requires knowledge of long-term wind conditions from either measurements or models. At the US East Coast there are few wind measurements and little experience with offshore wind farms. Therefore, we created a satellite-based high-resolution wind resource map to quantify spatial variations in the wind conditions over potential sites for wind farms and found larger variation than modelling suggested.
Anna-Maria Tilg, Charlotte Bay Hasager, Hans-Jürgen Kirtzel, and Poul Hummelshøj
Wind Energ. Sci., 5, 977–981, https://doi.org/10.5194/wes-5-977-2020, https://doi.org/10.5194/wes-5-977-2020, 2020
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Recently, there has been an increased awareness of leading-edge erosion of wind turbine blades. An option to mitigate the erosion at the leading edges is the deceleration of the wind turbine blades during severe precipitation events. This work shows that a vertically pointing radar can be used to nowcast precipitation events with the required spatial and temporal resolution. Furthermore, nowcasting allows a reduction in the rotational speed prior to the impact of precipitation on the blades.
Aurélien Babarit, Gaël Clodic, Simon Delvoye, and Jean-Christophe Gilloteaux
Wind Energ. Sci., 5, 839–853, https://doi.org/10.5194/wes-5-839-2020, https://doi.org/10.5194/wes-5-839-2020, 2020
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This paper addresses the topic of far-offshore wind energy exploitation. Far-offshore wind energy exploitation is not feasible with grid-connected floating wind turbines because grid-connection cost, installation cost and O&M cost would be prohibitive. An enabling technology is the energy ship concept, which is described and modeled in the paper. A design of an energy ship is proposed. It is estimated that it could produce 5 GWh per annum of chemical energy (methanol).
Michael Denis Mifsud, Tonio Sant, and Robert Nicholas Farrugia
Wind Energ. Sci., 5, 601–621, https://doi.org/10.5194/wes-5-601-2020, https://doi.org/10.5194/wes-5-601-2020, 2020
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In offshore wind, it is important to have an accurate wind resource assessment. Measure–correlate–predict (MCP) is a statistical method used in the assessment of the wind resource at a candidate site. Being a statistical method, it is subject to uncertainty, resulting in an uncertainty in the power output from the wind farm. This study involves the use of wind data from the island of Malta and uses a hypothetical wind farm to establish the best MCP methodology for the wind resource assessment.
Aurélien Babarit, Simon Delvoye, Gaël Clodic, and Jean-Christophe Gilloteaux
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2019-101, https://doi.org/10.5194/wes-2019-101, 2020
Revised manuscript not accepted
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This paper addresses the topic of far-offshore wind energy exploitation. Far-offshore wind energy exploitation is not feasible with current technology because grid-connection cost, installation cost and O&M cost would be prohibitive. An enabling technology for far-offshore wind energy is the energy ship concept, which has been described, modelled and analyzed in a companion paper. This paper provides a cost model and cost estimates for an energy system based on the energy ship concept.
Amber Kapoor, Slimane Ouakka, Sanjay R. Arwade, Julie K. Lundquist, Matthew A. Lackner, Andrew T. Myers, Rochelle P. Worsnop, and George H. Bryan
Wind Energ. Sci., 5, 89–104, https://doi.org/10.5194/wes-5-89-2020, https://doi.org/10.5194/wes-5-89-2020, 2020
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Offshore wind energy is a burgeoning area of renewable energy that is at an early stage of development in the United States. Exposure of offshore wind turbines to hurricanes must be assessed and mitigated to ensure the security of the renewable energy supply. This research assesses the impact of hurricane wind fields on the structural response of wind turbines. Such wind fields have characteristics that may pose heretofore unforeseen structural challenges to offshore wind turbines.
Jakob Ilsted Bech, Charlotte Bay Hasager, and Christian Bak
Wind Energ. Sci., 3, 729–748, https://doi.org/10.5194/wes-3-729-2018, https://doi.org/10.5194/wes-3-729-2018, 2018
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Rain erosion on wind turbine blades is a severe challenge for wind energy today. It causes significant losses in power production, and large sums are spent on inspection and repair.
Blade life can be extended, power production increased and maintenance costs reduced by rotor speed reduction at extreme precipitation events. Combining erosion test results, meteorological data and models of blade performance, we show that a turbine control strategy is a promising new weapon against blade erosion.
Tobias Ahsbahs, Merete Badger, Patrick Volker, Kurt S. Hansen, and Charlotte B. Hasager
Wind Energ. Sci., 3, 573–588, https://doi.org/10.5194/wes-3-573-2018, https://doi.org/10.5194/wes-3-573-2018, 2018
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Satellites offer wind measurements offshore and can resolve the wind speed on scales of up to 500 m. To date, this data is not routinely used in the industry for planning wind farms. We show that this data can be used to predict local differences in the mean wind speed around the Anholt offshore wind farm. With satellite data, site-specific wind measurements can be introduced early in the planning phase of an offshore wind farm and help decision makers.
Sebastian Schafhirt and Michael Muskulus
Wind Energ. Sci., 3, 25–41, https://doi.org/10.5194/wes-3-25-2018, https://doi.org/10.5194/wes-3-25-2018, 2018
Antonio Jarquin Laguna
Wind Energ. Sci., 2, 387–402, https://doi.org/10.5194/wes-2-387-2017, https://doi.org/10.5194/wes-2-387-2017, 2017
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This paper presents the idea of centralized electricity production in a wind farm by means of water technology. A new way of generating and transmitting wind energy is explored with no intermediate electrical conversion until the energy has reached the central offshore platform. This work includes the modelling and simulations of a hypothetical hydraulic wind farm, where results indicate good performance despite the turbulent wind conditions and wake effects.
Steffen Aasen, Ana M. Page, Kristoffer Skjolden Skau, and Tor Anders Nygaard
Wind Energ. Sci., 2, 361–376, https://doi.org/10.5194/wes-2-361-2017, https://doi.org/10.5194/wes-2-361-2017, 2017
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The industry standard for analysis of monopile foundations is inaccurate, and alternative models for foundation behavior are needed. This study investigates how four different soil-foundation models affect the fatigue damage of an offshore wind turbine with a monopile foundation. Stiffness and damping properties have a noticeable effect, in particular for idling cases. At mud-line, accumulated fatigue damage varied up to 22 % depending on the foundation model used.
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Short summary
The first larger offshore wind farms are reaching a mature age. Operators have to take actions for monitoring now in order to have accurate knowledge on structural reserves later. This knowledge is important to make decisions on lifetime extension. Many offshore wind turbines have one set of strain gauges already installed at the transition piece. We present a simple and robust method to extrapolate these measurements to other locations of the monopile without need of additional instrumentation.
The first larger offshore wind farms are reaching a mature age. Operators have to take actions...
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