scholarly journals Underwater Power Kites

2017 ◽  
Vol 139 (06) ◽  
pp. 38-43
Author(s):  
David J. Olinger
Keyword(s):  
Low Cost ◽  
Power Grid ◽  
Offshore Wind ◽  
Turbine Generator ◽  
Research Teams ◽  
Offshore Wind Turbines ◽  
Hydrokinetic Turbines ◽  
Available Technology ◽  
Economic Analyses ◽  
The Cost

This article discusses different features of underwater kites and its advantages in the turbine industry. The underwater kite moves fastest when it slaloms through the current in this way, much like a water skier. Electricity generated by the mounted turbine generator is transmitted along the tether to a moored, floating buoy, and then onto the power grid. This concept, now known as the Tethered Undersea Kite (TUSK), was first conceived by Magnus Landberg, a researcher in Sweden, in 2007. Underwater kites look to be feasible to build using commercial available technology. According to economic analyses conducted by other research teams, TUSK systems may be able to produce electricity at about half the current cost for fixed hydrokinetic turbines, and a bit below the cost of the power produced by offshore wind turbines. Those researchers attribute the lower costs to improved power-to-weight ratios derived from replacing the inner blades and support tower of a traditional turbine with a lightweight, low-cost tether.

Studying the Potential of a Novel Multiple-Generator Drivetrain in Wind Energy Conversion Systems

2013 ◽  
Author(s):  
N. Goudarzi ◽  
W. D. Zhu
Keyword(s):  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Wind Energy Conversion ◽  
Advantages And Disadvantages ◽  
Wind Energy Conversion Systems ◽  
Energy Conversion Systems ◽  
Switch Mechanism ◽  
The Cost ◽  
Operational Range

A novel multiple generator drivetrain (MGD), where a single large generator in a wind turbine is replaced by multiple generators with the same or different rated powers, is proposed along with an automatic switch mechanism as an alternative to an existing MGD. To better understand the advantages and disadvantages of having a MGD in onshore/offshore wind turbines, a MGD with a single or double stage gearbox and multiple generators is compared with a conventional drivetrain with a triple-stage gearbox and a large induction generator. A simple mathematical model for a MGD with an automatic switch is developed, a novel prototype of a MGD is designed and fabricated, and experiments are conducted on the prototype. It is concluded that a multiple-generator drivetrain with generators operating individually or in parallel through an automatic switch mechanism has a better potential of improving the efficiency and the reliability, expanding the operational range, and reducing the cost of offshore and onshore wind turbines than the existing MGD configuration.

Advanced Concept Offshore Wind Turbine Development

2014 ◽  
Vol 18 (5) ◽  
pp. 728-735 ◽  
Author(s):  
Abdollah A. Afjeh ◽  
◽  
Brett Andersen ◽  
Jin Woo Lee ◽  
Mahdi Norouzi ◽  
...  
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Cost Savings ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Offshore Wind Energy ◽  
Offshore Wind Turbines ◽  
Floating Foundation ◽  
The Cost

Development of novel offshore wind turbine designs and technologies are necessary to reduce the cost of offshore wind energy since offshore wind turbines need to withstand ice and waves in addition to wind, a markedly different environment from their onshore counterparts. This paper focuses on major design challenges of offshore wind turbines and offers an advanced concept wind turbine that can significantly reduce the cost of offshore wind energy as an alternative to the current popular designs. The design consists of a two-blade, downwind rotor configuration fitted to a fixed bottom or floating foundation. Preliminary results indicate that cost savings of nearly 25% are possible compared with the conventional upwind wind turbine designs.

scholarly journals Structure Design and Assessment of a Floating Foundation for Offshore Wind Turbines

2019 ◽  
Author(s):  
Qi Ye ◽  
Shanshan Cheng ◽  
Boksun Kim ◽  
Keri Collins ◽  
Gregorio Iglesias
Keyword(s):  
Structure Design ◽  
Offshore Wind ◽  
Wave Loads ◽  
Analysis And Design ◽  
Offshore Wind Turbines ◽  
Floating Foundation ◽  
Buckling Resistance ◽  
Offshore Floating Wind Turbine ◽  
The Cost ◽  
Stiffened Cylindrical Shells

Abstract This paper summarizes the assessment of the structural analysis and design of a floating foundation for offshore floating wind turbine (FWT) based on DNVGL standard and Eurocode in terms of economy and reliability. The wind loads are calculated using empirical equations. The wave loads are obtained and verified using various methods including hand calculation, AQWA and Flow-3D. It is found that the shell thickness could be reduced significantly by introducing the stiffeners (stringer or ring), which can decrease the weight of the hull and lower the cost. While DNVGL and Eurocode yield similar design solutions if using plane shell structures, Eurocode significantly underestimates the buckling resistance of stiffened cylindrical shells.

scholarly journals A Feedback Control Loop Optimisation Methodology for Floating Offshore Wind Turbines

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3490 ◽  
Author(s):  
Joannes Olondriz ◽  
Josu Jugo ◽  
Iker Elorza ◽  
Santiago Alonso-Quesada ◽  
Aron Pujana-Arrese
Keyword(s):  
Feedback Control ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Control Loop ◽  
Control Loops ◽  
Offshore Wind Turbines ◽  
Wind Turbine System ◽  
Floating Offshore Wind Turbines ◽  
The Cost

Wind turbines usually present several feedback control loops to improve or counteract some specific performance or behaviour of the system. It is common to find these multiple feedback control loops in Floating Offshore Wind Turbines where the system perferformance is highly influenced by the platform dynamics. This is the case of the Aerodynamic Platform Stabiliser and Wave Rejection feedback control loops which are complementaries to the conventional generator speed PI control loop when it is working in an above rated wind speed region. The multiple feedback control loops sometimes can be tedious to manually improve the initial tuning. Therefore, this article presents a novel optimisation methodology based on the Monte Carlo method to automatically improve the manually tuned multiple feedback control loops. Damage Equivalent Loads are quantified for minimising the cost function and automatically update the control parameters. The preliminary results presented here show the potential of this novel optimisation methodology to improve the mechanical fatigue loads of the desired components whereas maintaining the overall performance of the wind turbine system. This methodology provides a good balance between the computational complexity and result effectiveness. The study is carried out with the fully coupled non-linear NREL 5-MW wind turbine model mounted on the ITI Energy’s barge and the FASTv8 code.

scholarly journals Optimal Design of Rated Wind Speed and Rotor Radius to Minimizing the Cost of Energy for Offshore Wind Turbines

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2728 ◽  
Author(s):  
Longfu Luo ◽  
Xiaofeng Zhang ◽  
Dongran Song ◽  
Weiyi Tang ◽  
Jian Yang ◽  
...  
Keyword(s):  
Wind Speed ◽  
Optimal Design ◽  
Wind Energy ◽  
Wind Turbines ◽  
Offshore Wind ◽  
Design Parameters ◽  
Offshore Wind Energy ◽  
Offshore Wind Turbines ◽  
Cost Of Energy ◽  
The Cost

As onshore wind energy has depleted, the utilization of offshore wind energy has gradually played an important role in globally meeting growing green energy demands. However, the cost of energy (COE) for offshore wind energy is very high compared to the onshore one. To minimize the COE, implementing optimal design of offshore turbines is an effective way, but the relevant studies are lacking. This study proposes a method to minimize the COE of offshore wind turbines, in which two design parameters, including the rated wind speed and rotor radius are optimally designed. Through this study, the relation among the COE and the two design parameters is explored. To this end, based on the power-coefficient power curve model, the annual energy production (AEP) model is designed as a function of the rated wind speed and the Weibull distribution parameters. On the other hand, the detailed cost model of offshore turbines developed by the National Renewable Energy Laboratory is formulated as a function of the rated wind speed and the rotor radius. Then, the COE is formulated as the ratio of the total cost and the AEP. Following that, an iterative method is proposed to search the minimal COE which corresponds to the optimal rated wind speed and rotor radius. Finally, the proposed method has been applied to the wind classes of USA, and some useful findings have been obtained.

scholarly journals Study of offshore wind power penetration rate in gas turbine generator platform power grid

2021 ◽  
Vol 7 ◽  
pp. 141-146
Author(s):  
Qingguang Yu ◽  
Yuming Liu ◽  
Zhicheng Jiang ◽  
Le Li ◽  
Yingke Zhang ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Wind Power ◽  
Penetration Rate ◽  
Power Grid ◽  
Offshore Wind ◽  
Turbine Generator ◽  
Offshore Wind Power

Improving Gearbox Design and Analysis for Offshore Wind Turbines

2011 ◽  
Vol 86 ◽  
pp. 309-312
Author(s):  
Hui Long ◽  
Jing Ze Wu ◽  
Andrew Firth
Keyword(s):  
Wind Turbine ◽  
Fatigue Damage ◽  
Supervisory Control ◽  
Software Tool ◽  
Offshore Wind ◽  
Damage Estimation ◽  
Offshore Wind Turbines ◽  
Gear Trains ◽  
Design Software ◽  
The Cost

The paper outlines challenges in improving wind turbine availability to reduce the cost of offshore wind energy. It reports the development of a design software tool for wind turbine gearboxes. It facilitates efficient conceptual designs of wind turbine gearboxes with combinations of epicyclic and parallel gear trains. Field loading conditions are obtained by analysing SCADA (Supervisory Control and Data Acquisition) data to support fatigue damage estimation based on Miner’s rule. Results show that considerable overloading conditions are present which would result in significant fatigue damages to the gearbox.

An Evaluation of the Effect that Motions at the Nacelle have on the Cost of Floating Offshore Wind Turbines

2020 ◽  
Author(s):  
Miguel Taboada ◽  
Alvaro Ortega ◽  
Rafael Martín ◽  
Albino Pombo ◽  
Jaime Moreu
Keyword(s):  
Wind Turbines ◽  
Offshore Wind ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
The Cost

scholarly journals Ultrasound-Based Smart Corrosion Monitoring System for Offshore Wind Turbines

2022 ◽  
Vol 12 (2) ◽  
pp. 808
Author(s):  
Upeksha Chathurani Thibbotuwa ◽  
Ainhoa Cortés ◽  
Andoni Irizar
Keyword(s):  
Monitoring System ◽  
Wind Turbines ◽  
Low Cost ◽  
Offshore Wind ◽  
Corrosion Monitoring ◽  
Ultrasound Technique ◽  
Offshore Wind Turbines ◽  
Thickness Loss ◽  
On Line ◽  
Pulse Echo

The ultrasound technique is a well-known non-destructive and efficient testing method for on-line corrosion monitoring. Wall thickness loss rate is the major parameter that defines the corrosion process in this approach. This paper presents a smart corrosion monitoring system for offshore wind turbines based on the ultrasound pulse-echo technique. The solution is first developed as an ultrasound testbed with the aim of upgrading it into a low-cost and low-power miniaturized system to be deployed inside offshore wind turbines. This paper discusses different important stages of the presented monitoring system as design methodology, the precision of the measurements, and system performance verification. The obtained results during the testing of a variety of samples show meaningful information about the thickness loss due to corrosion. Furthermore, the developed system allows us to measure the Time-of-Flight (ToF) with high precision on steel samples of different thicknesses and on coated steel samples using the offshore standard coating NORSOK 7A.

Concrete is the Future for Offshore Foundations

2005 ◽  
Vol 29 (6) ◽  
pp. 531-563 ◽  
Author(s):  
Per Vølund
Keyword(s):  
Wind Turbines ◽  
Lower Cost ◽  
Low Cost ◽  
Extra Cost ◽  
Offshore Wind ◽  
Light Weight ◽  
Conceptual Foundation ◽  
Offshore Wind Turbines ◽  
The Future ◽  
Main Construction

This paper compares the costs of using concrete foundations against steel monopile foundations for offshore wind turbines, and argues that concrete foundations will be cheaper. Most offshore windfarms have steel monopile foundations, but in Denmark concrete gravity foundations have been used with success. Two projects have tendered for steel monopiles and for concrete foundations and have implemented the concrete foundations that proved cheaper. No project has tendered for both foundation concepts and chosen steel monopiles. Nysted Offshore Windfarm with concrete foundations has the cheapest foundations of any offshore windfarm so far. A conceptual foundation study carried out for the London Array West Offshore Windfarm indicates that the same method and very low-cost foundations as for Nysted can be used. Optimised design of light-weight concrete constructions is the key to low-cost installation. Cheap manufacture can be carried out near the site or at even lower cost in Eastern Europa from where it can be shipped at little extra cost. The main construction of steel monopile foundations will become twice as costly as of concrete gravity foundations, and though installation is more costly for the gravity foundations it seems most likely that tendering between steel monopile and concrete gravity for London Array West will prove concrete considerably cheaper. It is argued that these considerations are to a wide extent generally valid, and also for very large turbines in deeper water. Concrete foundations will in 2006 be installed at Lillegrunden Offshore Windfarm in Sweden, and at Belgian Thornton Bank in 2006–7. So indications are strong that concrete is the future for offshore foundations.

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