Transient LES of an offshore wind turbine

Abstract. The estimation of the cost of energy of offshore wind farms has a high uncertainty, which is partly due to the lacking accuracy of information on wind conditions and wake losses inside of the farm. Wake models that aim on reducing the uncertainty by modeling the wake interaction of turbines for various wind conditions need to be validated with measurement data before they can be considered as a reliable estimator. A methodology is shown to create realistic transient wind conditions in a Large-Eddy-Simulation of a marine boundary layer interacting with an offshore wind turbine for a direct comparison of modeled with measured flow data. A mesoscale simulation is used for determining the boundary conditions of the model. The simulations of the ambient wind conditions and the wake simulation generally show a good agreement with measurements from a met mast and lidar measurements, respectively. Advanced metrics to describe the wake shape and development are derived from simulations and measurements but a quantitative comparison is difficult due to the scarcity and the low sampling rate of the available measurement data. The methodology presents a possibility to compare flow measurements with simulations. Due to the implementation of changing wind conditions in the LES it could be also beneficial for case studies of wind turbine and wind farm control.

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Transient LES of an offshore wind turbine

Wind Energy Science ◽

10.5194/wes-2-603-2017 ◽

2017 ◽

Vol 2 (2) ◽

pp. 603-614 ◽

Cited By ~ 5

Author(s):

Lukas Vollmer ◽

Gerald Steinfeld ◽

Martin Kühn

Keyword(s):

Wind Turbine ◽

Wind Farm ◽

Mesoscale Model ◽

Sampling Rate ◽

Measurement Data ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Offshore Wind Farms ◽

Synoptic Wind

Abstract. The estimation of the cost of energy of offshore wind farms has a high uncertainty, which is partly due to the lacking accuracy of information on wind conditions and wake losses inside of the farm. Wake models that aim to reduce the uncertainty by modeling the wake interaction of turbines for various wind conditions need to be validated with measurement data before they can be considered as a reliable estimator. In this paper a methodology that enables a direct comparison of modeled with measured flow data is evaluated. To create the simulation data, a model chain including a mesoscale model, a large-eddy-simulation (LES) model and a wind turbine model is used. Different setups are compared to assess the capability of the method to reproduce the wind conditions at the hub height of current offshore wind turbines. The 2-day-long simulation of the ambient wind conditions and the wake simulation generally show good agreements with data from a met mast and lidar measurements, respectively. Wind fluctuations due to boundary layer turbulence and synoptic-scale motions are resolved with a lower representation of mesoscale fluctuations. Advanced metrics to describe the wake shape and development are derived from simulations and measurements but a quantitative comparison proves to be difficult due to the scarcity and the low sampling rate of the available measurement data. Due to the implementation of changing synoptic wind conditions in the LES, the methodology could also be beneficial for case studies of wind farm performance or wind farm control.

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Analysis of rotorcraft wind turbine wake encounters using piloted simulation

CEAS Aeronautical Journal ◽

10.1007/s13272-021-00495-w ◽

2021 ◽

Author(s):

Alexander Štrbac ◽

Tanja Martini ◽

Daniel H. Greiwe ◽

Frauke Hoffmann ◽

Michael Jones

Keyword(s):

Wind Turbine ◽

Alternative Energy ◽

Wind Farm ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Vortex Wake ◽

Offshore Wind Farms ◽

Turbine Wake ◽

Wind Turbine Wake

AbstractThe use of offshore wind farms in Europe to provide a sustainable alternative energy source is now considered normal. Particularly in the North Sea, a large number of wind farms exist with a significant distance from the coast. This is becoming standard practice as larger areas are required to support operations. Efficient transport and monitoring of these wind farms can only be conducted using helicopters. As wind turbines continue to grow in size, there is a need to continuously update operational requirements for these helicopters, to ensure safe operations. This study assesses German regulations for flight corridors within offshore wind farms. A semi-empirical wind turbine wake model is used to generate velocity data for the research flight simulator AVES. The reference offshore wind turbine NREL 5 MW has been used and scaled to represent wind turbine of different sizes. This paper reports result from a simulation study concerning vortex wake encounter during offshore operations. The results have been obtained through piloted simulation for a transport case through a wind farm. Both subjective and objective measures are used to assess the severity of vortex wake encounters.

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Study on the Coexistence of Offshore Wind Farms and Cage Culture

Water ◽

10.3390/w13141960 ◽

2021 ◽

Vol 13 (14) ◽

pp. 1960

Author(s):

Hsing-Yu Wang ◽

Hui-Ming Fang ◽

Yun-Chih Chiang

Keyword(s):

Wind Turbine ◽

Wind Power ◽

Wind Farm ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Offshore Wind Farms ◽

Offshore Wind Power ◽

Waves And Currents ◽

The Waves

In this study, a hydrodynamic model was used that includes the effects of wave–current interactions to simulate the wave and current patterns before and after offshore wind turbine installation in western Taiwan. By simulating the waves and currents after the offshore wind turbine was established, the waves and currents caused by the wind turbine were seen to have a limited range of influence, which is probably within an area about four to five times the size of the diameter (12–15 m) of the foundation structure. Overall, the analysis of the simulation results of the wave and current patterns after the offshore wind turbines were established shows that the underwater foundation only affected the local area near the pile structure. The wind farm (code E) of the research case can be equipped with about 720 cage cultures; if this is extended to other wind farms in the western sea area, it should be possible to produce economic-scale farming operations such as offshore wind power and fisheries. However, this study did not consider the future operation of the entire offshore wind farm. If the operation and maintenance of offshore wind farms are not affected, and if the consent of the developer is obtained, it should be possible to use this method to provide economically large-scale farming areas as a mutually beneficial method for offshore wind power generation and fisheries.

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Optimization of O&M for Offshore Wind Farms Modelling for WMTC Conferences

10.5957/wmtc-2015-214 ◽

2015 ◽

Author(s):

Thomas Nivet ◽

Ema Muk-Pavic

Keyword(s):

Wind Farm ◽

Wind Farms ◽

Cost Effective ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Offshore Wind Farms ◽

Climate Conditions ◽

Operation Analysis ◽

Cost Effective Approach ◽

Failure Evaluation

Offshore wind energy is one of the most upcoming sources of energy, and it is already partially replacing the fossil fuelled power production. However, offshore wind turbine technology is also associated with harsher weather environment. Indeed, it experiences more challenging wind and wave conditions, which in turn limits the vessels capabilities to access the wind farms. Additionally, with the constant rise of power utilization, improvements in the Operation Maintenance (O&M) planning are crucial for the development of large isolated offshore wind farms. Improvements in the planning of the O&M for offshore wind farms could lead to considerable reduction in costs. For this reason, the interest of this research paper is the investigation of the most cost effective approach to offshore turbine maintenance strategies. This objective is achieved by implementing a simulation approach that includes a climate conditions analysis, an operation analysis, a failure evaluation and a simulation of the repairs. This paper points out how different O&M strategies can influence the sustainability of a wind farm.

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Optimization of Wind Turbine Interconnections in an Offshore Wind Farm Using Metaheuristic Algorithms

Sustainability ◽

10.3390/su12145761 ◽

2020 ◽

Vol 12 (14) ◽

pp. 5761 ◽

Cited By ~ 1

Author(s):

Chakib El Mokhi ◽

Adnane Addaim

Keyword(s):

Wind Energy ◽

Wind Turbine ◽

Wind Farm ◽

Renewable Energy Sources ◽

Wind Farms ◽

Optimization Methods ◽

Network Routing ◽

Metaheuristic Algorithms ◽

Offshore Wind ◽

Offshore Wind Farms

Wind energy is currently one of the fastest-growing renewable energy sources in the world. For this reason, research on methods to render wind farms more energy efficient is reasonable. The optimization of wind turbine positions within wind farms makes the exploitation of wind energy more efficient and the wind farms more competitive with other energy resources. The investment costs alone for substation and electrical infrastructure for offshore wind farms run around 15–30% of the total investment costs of the project, which are considered high. Optimizing the substation location can reduce these costs, which also minimizes the overall cable length within the wind farm. In parallel, optimizing the cable routing can provide an additional benefit by finding the optimal grid network routing. In this article, the authors show the procedure on how to create an optimized wind farm already in the design phase using metaheuristic algorithms. Besides the optimization of wind turbine positions for more energy efficiency, the optimization methods of the substation location and the cable routing for the collector system to avoid cable losses are also presented.

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Performance Analysis of Offshore Mono-Pile Wind Turbine Co-Located With Floating Photovoltaic Systems in Shark Bay, Australia

10.1115/omae2021-63852 ◽

2021 ◽

Author(s):

Morteza Bahadori ◽

Hassan Ghassemi

Keyword(s):

Wind Turbine ◽

Hybrid System ◽

Wind Farm ◽

Wind Farms ◽

Power Production ◽

Offshore Wind ◽

Offshore Wind Farm ◽

Offshore Wind Farms ◽

Shark Bay

Abstract In recent years, as more offshore wind farms have been constructed, the possibility of integrating various offshore renewable technologies is increased. Using offshore wind and solar power resources as a hybrid system provides several advantages including optimized marine space utilization, reduced maintenance and operation costs, and relieving wind variability on output power. In this research, both offshore wind and solar resources are analyzed based on accurate data through a case study in Shark Bay (Australia), where bathymetric information confirms using offshore bottom-fixed wind turbine regarding the depth of water. Also, the power production of the hybrid system of co-located bottom-fixed wind turbine and floating photovoltaic are investigated with the technical characteristics of commercial mono-pile wind turbine and photovoltaic panels. Despite the offshore wind, the solar energy output has negligible variation across the case study area, therefore using the solar platform in deep water is not an efficient option. It is demonstrated that the floating solar has a power production rate nearly six times more than a typical offshore wind farm with the same occupied area. Also, output energy and surface power density of the hybrid offshore windsolar system are improved significantly compared to a standalone offshore wind farm. The benefits of offshore wind and solar synergies augment the efficiency of current offshore wind farms throughout the world.

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The Influence of Selected Strain-Based Failure Criteria on Ship Structure Damage Resulting from a Collision with an Offshore Wind Turbine Monopile

Polish Maritime Research ◽

10.2478/pomr-2021-0048 ◽

2021 ◽

Vol 28 (4) ◽

pp. 42-52

Author(s):

Karol Niklas ◽

Alicja Bera

Keyword(s):

Wind Turbine ◽

Strain Curve ◽

Wind Farms ◽

Linear Representation ◽

Failure Criteria ◽

Green Energy ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Offshore Wind Farms ◽

Structure Damage

Abstract Offshore wind farms are developing well all over the world, providing green energy from renewable sources. The evaluation of possible consequences of a collision involves Finite Element computer simulations. The goal of this paper was to analyse the influence of selected strain-based failure criteria on ship damage resulting from a collision with an offshore wind turbine monopile. The case of a collision between an offshore supply vessel and a monopile-type support structure was examined. The results imply that simulation assumptions, especially the failure criteria, are very important. It was found that, using the strain failure criteria according to the minimum values required by the design rules, can lead to an underestimation of the ship damage by as much as 6 times, for the length of the hull plate, and 9 times, for the area of the ship hull opening. Instead, the adjusted formula should be used, taking into account both the FE element size and the shell thickness. The influence of the non-linear representation of the stress-strain curve was also pointed out. Moreover, a significant influence of the selected steel grade on collision damages was found.

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Monitor Method of Offshore Wind Turbine Based on Memory-Like and Neural Network Expert System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.635-637.687 ◽

2014 ◽

Vol 635-637 ◽

pp. 687-693

Author(s):

Ling Xia Su ◽

Xia Xia Ma

Keyword(s):

Fault Diagnosis ◽

Wind Turbine ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Offshore Wind Farms ◽

Onshore Wind ◽

Diagnosis Method ◽

Simulation Results ◽

Improve Reliability

The number of offshore wind farms increases gradually because of the high capability of power generation. However, the costs of manufacturing, logistics, installation and maintenance of offshore wind turbine are higher than those of onshore wind turbine. Thus the introduction of fault diagnosis is considered as a suitable way to improve reliability of wind turbine and reduce costs of repairs and casualties. In this paper, 3 major failures of direct-driven wind turbine according to urgency and system responses are discussed. A "memory-like" model pretreatment method and a fault diagnosis method for the failures are investigated. The simulation results show that total amount of fault data to be processed and stored is reduced, and difficulties of knowledge gaining and fault reasoning are also decreased.

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Global offshore wind turbine dataset

Scientific Data ◽

10.1038/s41597-021-00982-z ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Ting Zhang ◽

Bo Tian ◽

Dhritiraj Sengupta ◽

Lei Zhang ◽

Yali Si

Keyword(s):

Environmental Impact ◽

Wind Turbine ◽

Wind Turbines ◽

Wind Farm ◽

Wind Farms ◽

Google Earth ◽

Green Energy ◽

Offshore Wind ◽

Validation Dataset ◽

Offshore Wind Turbine

AbstractOffshore wind farms are widely adopted by coastal countries to obtain clean and green energy; their environmental impact has gained an increasing amount of attention. Although offshore wind farm datasets are commercially available via energy industries, records of the exact spatial distribution of individual wind turbines and their construction trajectories are rather incomplete, especially at the global level. Here, we construct a global remote sensing-based offshore wind turbine (OWT) database derived from Sentinel-1 synthetic aperture radar (SAR) time-series images from 2015 to 2019. We developed a percentile-based yearly SAR image collection reduction and autoadaptive threshold algorithm in the Google Earth Engine platform to identify the spatiotemporal distribution of global OWTs. By 2019, 6,924 wind turbines were constructed in 14 coastal nations. An algorithm performance analysis and validation were performed, and the extraction accuracies exceeded 99% using an independent validation dataset. This dataset could further our understanding of the environmental impact of OWTs and support effective marine spatial planning for sustainable development.

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Simplified Floating Wind Turbine for Real-Time Simulation of Large-Scale Floating Offshore Wind Farms

Energies ◽

10.3390/en14154571 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4571

Author(s):

Thanh-Dam Pham ◽

Minh-Chau Dinh ◽

Hak-Man Kim ◽

Thai-Thanh Nguyen

Keyword(s):

Wind Turbine ◽

Real Time ◽

Large Scale ◽

Wind Farms ◽

Offshore Wind ◽

Offshore Wind Turbine ◽

Offshore Wind Farms ◽

Real Time Simulation ◽

The Real ◽

Time Simulation

Floating offshore wind has received more attention due to its advantage of access to incredible wind resources over deep waters. Modeling of floating offshore wind farms is essential to evaluate their impacts on the electric power system, in which the floating offshore wind turbine should be adequately modeled for real-time simulation studies. This study proposes a simplified floating offshore wind turbine model, which is applicable for the real-time simulation of large-scale floating offshore wind farms. Two types of floating wind turbines are evaluated in this paper: the semi-submersible and spar-buoy floating wind turbines. The effectiveness of the simplified turbine models is shown by a comparison study with the detailed FAST (Fatigue, Aerodynamics, Structures, and Turbulence) floating turbine model. A large-scale floating offshore wind farm including eighty units of simplified turbines is tested in parallel simulation and real-time software (OPAL-RT). The wake effects among turbines and the effect of wind speeds on ocean waves are also taken into account in the modeling of offshore wind farms. Validation results show sufficient accuracy of the simplified models compared to detailed FAST models. The real-time results of offshore wind farms show the feasibility of the proposed turbine models for the real-time model of large-scale offshore wind farms.

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