Wind Energy Engineering: A Handbook for Onshore and Offshore Wind Turbines

Front Cover
Wind Energy Engineering
Copyright Page
Contents
List of Contributors
Preface
A. Introduction
	1 Why wind energy
		1.1 Introduction
		1.2 Climate change and the growth of the wind turbine industry
		1.3 Background
		1.4 Advantages of wind energy
		1.5 Challenges facing the wind turbine industry
		1.6 The potential of wind energy worldwide
		References
	2 History of harnessing wind power
		2.1 Introduction
		2.2 Wind machines in antiquity
		2.3 Islamic civilization windmills
		2.4 Medieval European windmills
		2.5 Aegean and Mediterranean windmills
		2.6 Dutch and European windmills
		2.7 The American windmill
		2.8 Historical developments
		2.9 Windmills applications
		2.10 Discussion
		References
B. Wind resource and wind energy
	3 Wind power fundamentals
		3.1 Wind physics basics: what is wind and how wind is generated
		3.2 Wind types: a brief overview of wind power meteorology
		3.3 Fundamental equation of wind power: kinetic energy flux and wind power density
		3.4 Wind power capture: efficiency in extracting wind power
		3.5 Conclusion
		References
	4 Estimation of wind energy potential and prediction of wind power
		4.1 Introduction
		4.2 Principles for successful development for a wind assessment program
		4.3 Main aspects of a wind assessment program
		4.4 Estimating wind power based on wind speed measurements
		4.5 Wind resource estimation project; scope and methods
		4.6 Further considerations for wind speed assessment
		4.7 Wind speed and power forecasting
		4.8 Conclusions
		References
	5 Global potential for wind-generated electricity
		5.1 Introduction
		5.2 Methodology
		5.3 Results
			5.3.1 Global perspective
			5.3.2 US perspective
			5.3.3 China perspective
		5.4 Concluding remarks
		Acknowledgments
		References
	6 Achieving carbon neutrality: the future of wind energy development in China
		6.1 Introduction
		6.2 Wind energy development in China
			6.2.1 Overview
			6.2.2 Electricity market and wind energy market in China
				6.2.2.1 Electricity market and wind energy market
				6.2.2.2 Key players in the wind energy market in China
					6.2.2.2.1 Wind energy developers
					6.2.2.2.2 Wind turbine manufacturers
					6.2.2.2.3 The central government
					6.2.2.2.4 The local governments
					6.2.2.2.5 Grid companies
		6.3 Wind energy development in China: barriers and drivers
			6.3.1 Barriers to wind energy development in China
				6.3.1.1 Overcapacity in nonrenewable power plants
				6.3.1.2 Wind curtailment
				6.3.1.3 Poor grid connectivity
				6.3.1.4 Lack of a well-functioned ancillary service market
				6.3.1.5 Lack of demand response and energy storage
				6.3.1.6 Differential priorities between the central government and the local governments
				6.3.1.7 Vested interests between coal companies and the government
			6.3.2 Drivers of wind energy development in China
				6.3.2.1 Energy coordination
				6.3.2.2 Coal-fired power plants retrofit and energy storage
				6.3.2.3 Smart demand response
				6.3.2.4 Emerging ancillary service market
				6.3.2.5 Carbon trading and carbon reduction target
		6.4 The future of wind energy development in China
			6.4.1 Distributed generation deployment and proactive transmission planning
			6.4.2 Offshore wind power planning
			6.4.3 Smart grid
			6.4.4 Merit-order-based dispatch
		6.5 Conclusion
		Acknowledgment
		References
	7 Vertical wind speed profiles in atmospheric boundary layer flows
		7.1 Introduction
		7.2 Diversity of wind speed profiles
		7.3 Similarity theory
			7.3.1 Logarithmic law of the wall
			7.3.2 Monin–Obukhov similarity theory
			7.3.3 Extension of Monin–Obukhov similarity theory
			7.3.4 Geostrophic drag laws
		7.4 Empirical formulations
			7.4.1 Power law
			7.4.2 Profiles for strong winds
		7.5 Concluding remarks
		Acknowledgments
		References
C. Wind turbine technology
	8 Wind turbine technologies
		8.1 Introduction
		8.2 Overview of wind turbine components
			8.2.1 Aerodynamic rotor
			8.2.2 Transmission system
			8.2.3 Generator
				8.2.3.1 Synchronous generator
				8.2.3.2 Asynchronous (induction) generator
			8.2.4 Power electronic interface
			8.2.5 Control system and wind turbine control capabilities
		8.3 Contemporary wind turbine technologies
			8.3.1 Fixed-speed wind turbines (Type 1)
			8.3.2 Limited variable speed wind turbines (Type 2)
			8.3.3 Variable speed wind turbines with partial scale power converter (Type 3)
			8.3.4 Variable speed wind turbines with full-scale power converter (Type 4)
		8.4 Conclusions
		References
	9 Small-scale wind turbines
		9.1 The fundamental concern for micro-wind: the wind resource
			9.1.1 Building-mounted turbines
		9.2 Rural building mounted turbine
		9.3 Suburban building mounted turbine
		9.4 Urban building mounted turbine
		9.5 Summary findings: building mounted turbines
		9.6 Field trial observations: pole mounted turbines
		9.7 The future for micro-wind
		9.8 Conclusions
		Acknowledgments
		References
	10 Civil engineering aspects of a wind farm and wind turbine structures
		10.1 Energy challenge
		10.2 Wind farm and Fukushima nuclear disaster
			10.2.1 Case study: performance of near-shore wind farm during 2012 Tohoku earthquake
				10.2.1.1 Why did the wind farm stand up?
		10.3 Wind farm site selection
			10.3.1 Case studies: Burbo wind farm (see Fig. 10.6 for location)
			10.3.2 ASIDE on the economics
		10.4 General arrangement of a wind farm
		10.5 Choice of foundations for a site
		10.6 Foundation types
		10.7 Gravity-based foundation system
		10.8 Suction buckets or caissons
		10.9 Pile foundations
		10.10 Seabed frame or jacket supporting supported on pile or caissons
		10.11 Floating turbine system
		10.12 Site layout, spacing of turbines, and geology of the site
			10.12.1 Case study: Westermost Rough
		10.13 Economy of scales for foundation
		References
	11 Aerodynamics and the design of horizontal axis wind turbine
		11.1 Introduction
		11.2 A short description on how a wind turbine works
		11.3 1-D momentum equations
		11.4 Blade element momentum
			11.4.1 The blade element momentum method
		11.5 Use of steady blade element momentum method
		11.6 Aerodynamic blade design
		11.7 Unsteady loads and fatigue
		11.8 Brief description of design process
		References
	12 Civil engineering challenges associated with design of offshore wind turbines with special reference to China
		12.1 Offshore wind potential in China
		12.2 Dynamic sensitivity of offshore wind turbine structures
		12.3 Dynamic issues in support structure design
			12.3.1 Importance of foundation design
		12.4 Types and nature of the loads acting on the foundations
			12.4.1 Loads acting on the foundations
			12.4.2 Extreme wind and wave loading conditions in Chinese waters
				12.4.2.1 Case study: Typhoon-related damage to wind turbines in China
			12.4.3 Wave condition
		12.5 Ground conditions in Chinese waters
			12.5.1 Bohai Sea
		12.6 Seismic effects
		12.7 A note on serviceability limit state design criteria
			12.7.1 An example of a method to predict the required foundation stiffness
		12.8 Challenges in analysis of dynamic soil-structure interaction
		12.9 Foundation design
			12.9.1 Challenges in monopile foundation design and installation
			12.9.2 Jacket on flexible piles
		12.10 Concluding remarks
		References
	13 Numerical methods for soil-structure interaction analysis of offshore wind turbine foundations
		13.1 Introduction
			13.1.1 Need for numerical analysis for carrying out the design
		13.2 Types of numerical analysis
			13.2.1 Standard method based on beam on nonlinear Winkler spring
			13.2.2 Advanced analysis (finite element analysis & discrete element modeling) to study foundation-soil interaction
				13.2.2.1 Different soil models used in finite element analysis
				13.2.2.2 Discrete element model analysis basics
		13.3 Example application of numerical analysis to study soil-structure interaction of monopile
			13.3.1 Monopile analysis using discrete element method
			13.3.2 Monopile analysis using FEM using ANSYS software
		References
	14 Reliability of wind turbines
		14.1 Introduction
		14.2 Fundamentals
			14.2.1 Terminology
				14.2.1.1 Reliability
				14.2.1.2 Metrics
			14.2.2 Taxonomy
			14.2.3 Failure types
		14.3 Current status
		14.4 Reliability engineering
			14.4.1 Data collection
			14.4.2 Model development
			14.4.3 Forecasting
		14.5 Case studies
			14.5.1 Gearbox spares planning
			14.5.2 Pitch bearing maintenance scheduling
		14.6 Conclusions
		Acknowledgments
		References
	15 Practical method to estimate foundation stiffness for design of offshore wind turbines
		15.1 Introduction
		15.2 Methods to estimate foundation stiffness
			15.2.1 Simplified method (closed form solutions)
			15.2.2 Standard method
			15.2.3 Advanced method
		15.3 Obtaining foundation stiffness from standard and advanced method
		15.4 Example problem [monopile for Horns Rev 1]
			15.4.1 Elastic-plastic formulation
			15.4.2 API formulation
		15.5 Discussion and application of foundation stiffness
			15.5.1 Pile head deflections and rotations
				15.5.1.1 Elastic-plastic
				15.5.1.2 API formulation
			15.5.2 Prediction of the natural frequency
			15.5.3 Comparison with SAP 2000 analysis
		Nomenclature
		References
	16 Physical modeling of offshore wind turbine model for prediction of prototype response
		16.1 Introduction
			16.1.1 Complexity of external loading conditions
			16.1.2 Design challenges
			16.1.3 Technical review/appraisal of new types of foundations
			16.1.4 Physical modeling for prediction of prototype response
		16.2 Physical modeling of offshore wind turbines
			16.2.1 Dimensional analysis
			16.2.2 Definition of scaling laws for investigating offshore wind turbines
		16.3 Scaling laws for offshore wind turbines supported monopiles
			16.3.1 Monopile foundation
			16.3.2 Strain field in the soil around the laterally loaded pile
			16.3.3 Cyclic stress ratio in the soil in the shear zone
			16.3.4 Rate of soil loading
			16.3.5 System dynamics
			16.3.6 Bending strain in the monopile
			16.3.7 Fatigue in the monopile
			16.3.8 Example of experimental investigation for studying the long-term response of 1–100 scale offshore wind turbine
		16.4 Scaling laws for offshore wind turbines supported on multipod foundations
			16.4.1 Typical experimental setups and results
		16.5 Conclusions
		References
	17 Seismic design and analysis of offshore wind turbines
		17.1 Introduction
		17.2 Methodology of design for bottom fixed offshore and nearshore wind farms
			17.2.1 Ground motion selection
			17.2.2 Site response analysis
			17.2.3 Soil-structure interaction
			17.2.4 Identification of liquefiable or strain softening layers
			17.2.5 Load utilization ratio analysis
			17.2.6 Plotting the moment (MR) and lateral (HR) resisting capacity curve in liquefiable and nonliquefiable soil
			17.2.7 Examples of the moment and lateral resisting capacity curve in liquefiable soil
			17.2.8 Analysis of soil settlement postliquefaction
			17.2.9 An example of 15MW NREL wind turbine on jacket and monopile foundations
				17.2.9.1 Soil profile and site response analysis
				17.2.9.2 Loads
					17.2.9.2.1 Earthquake loads
					17.2.9.2.2 Wind and wave loads
				17.2.9.3 Soil-structure interaction analysis
		17.3 Methodology of analyzing floating wind turbines
			17.3.1 Employed Modeling Details
		Summary
		References
	18 Seismic hazards associated with offshore wind farms
		18.1 Introduction
		18.2 Seismic hazard of bottom fixed offshore wind turbines
			18.2.1 Liquefaction and possible hazards
			18.2.2 Tsunami
			18.2.3 Example of deterministic seismic hazard analysis of Gujarat Coast, India [56]
		18.3 Seismic hazards of floating offshore wind farms
			18.3.1 Fault rupture
			18.3.2 Submarine landslide
			18.3.3 Tsunami
			18.3.4 Liquefaction
		18.4 Miscellaneous hazards
			18.4.1 Blade collision during a seismic event
			18.4.2 Electrical cables failure
		18.5 Summary of demands of offshore wind turbines
		References
	19 Some challenges and opportunities around lifetime performance and durability of wind turbines
		19.1 Introduction
		19.2 Fatigue, repowering, and repurposing
			19.2.1 Fatigue
			19.2.2 Repowering
			19.2.3 Repurposing
		19.3 Scour aspects
		19.4 Degradation aspects
		19.5 Monitoring aspects
		19.6 Understanding uncertainties
		19.7 Conclusions
		References
	20 A review of wind power in grid codes: current state and future challenges
		20.1 Introduction
			20.1.1 Near horizon overview of power systems
			20.1.2 Grid code
			20.1.3 Challenges in modern power systems
			20.1.4 Promising technologies for modern power systems
		20.2 Wind power in European grid codes
			20.2.1 European network codes development
			20.2.2 Structure and characteristics of network code requirements
			20.2.3 Grid code compliance—general aspects
			20.2.4 RfG by countries
		20.3 Wind power performance requirements in North America
			20.3.1 Federal energy regulatory commission
				20.3.1.1 Wind generation interconnection requirements
				20.3.1.2 Incentives to support the grid reliability
			20.3.2 Electric reliability organization
			20.3.3 Transmission owner
			20.3.4 Future standards
		20.4 Future grid code challenges
		Acknowledgements
		References
	21 Intelligent design and optimization of wind turbines
		21.1 Introduction
		21.2 Intelligent design and optimization methods for wind turbines
			21.2.1 Supervised learning-based methods
			21.2.2 Unsupervised learning-based methods
			21.2.3 Reinforcement learning-based methods
		21.3 Intelligent design and optimization applications for wind turbines
			21.3.1 Blades
			21.3.2 Towers
			21.3.3 Generators
			21.3.4 Other mechanical and electrical components
		21.4 Conclusions
		Acknowledgments
		Nomenclacture
		References
	22 Wind and hybrid power systems: reliability-based assessment
		22.1 Introduction
		22.2 Wind power systems
			22.2.1 Stochastic modeling of wind power
			22.2.2 Reliability-based assessment
		22.3 Hybrid power systems
		22.4 Concluding remarks
		References
	23 Multifidelity simulation tools for modern wind turbines
		23.1 Introduction
		23.2 Blade aerodynamics
		23.3 Rotor aerodynamics
		23.4 Rotor blades’ structural dynamics for aeroelasticity
		23.5 Concluding remarks
		References
	24 Wind turbine supporting tower structural health monitoring and vibration control
		24.1 Introduction
		24.2 Dynamic response of wind turbine tower under severe environmental conditions
			24.2.1 Analysis of wind turbine under tornado
			24.2.2 Structural response of wind turbine to downburst
			24.2.3 Seismic response of wind turbine tower
		24.3 Wind turbine tower testing technique and structural health monitoring
			24.3.1 Noncontact vibration measurement methods for wind turbine tower
			24.3.2 Modal parameter identification of wind turbine tower
			24.3.3 Damping identification and aerodynamic damping of wind turbine in operation for seismic analysis
		24.4 Vibration control of wind turbine tower
			24.4.1 Effect of soil-structure interaction on the design of tuned mass dampers
			24.4.2 Novel vibration control system for wind turbine tower
		24.5 Summary
		References
	25 Innovative foundation design for offshore wind turbines
		25.1 Introduction
		25.2 Need for new types of foundations
		25.3 Inspiration for hybrid foundations
		25.4 Hybrid monopile foundation concept
		25.5 Verification and validation
			25.5.1 Validation step 1: numerical models validation via centrifuge test
				25.5.1.1 Comparison against the centrifuge tests of Wang et al. [1]
			25.5.2 Validation step 2 experiment evaluation
				25.5.2.1 1-g testing
				25.5.2.2 Load utilization framework
				25.5.2.3 Test preparation
		25.6 Steps to set up numerical model for hybrid monopile
			25.6.1 Parametric study
			25.6.2 Soil profile
			25.6.3 Numerical results
		25.7 Further application of hybrid foundation study
			25.7.1 Retrofitting of existing monopiles
		25.8 Discussion and conclusions
		References
		Further reading
	26 Gravity-based foundation for offshore wind turbines
		26.1 Introduction to gravity-based foundations
			26.1.1 Advantages and challenges of the gravity-based structure system
			26.1.2 Shapes and sizes
		26.2 Load and design consideration
			26.2.1 Load combination
			26.2.2 Limit state design considerations
		26.3 Sizing of gravity-based structure based on ultimate limit state and the effective area method
			26.3.1 Converting (V, M, H) loading into (V, H) loading through an effective area approach
		26.4 Tower–gravity-based structure connection
			26.4.1 Check for sliding resistance
			26.4.2 Work example for a gravity-based structure supporting 5MW turbine
			26.4.3 Loads on the foundation
			26.4.4 Vertical load
			26.4.5 Initial dimensions and ballast load
				26.4.5.1 Base of the tower
			26.4.6 Calculation of ballast needed
			26.4.7 Ultimate geotechnical capacity
			26.4.8 Check for sliding resistance
			26.4.9 Foundation stiffness
		26.5 Summary
		References
D. Storing energy
	27 Greenhouse gas emissions from storing energy from wind turbines
		27.1 The need for storage
			27.1.1 Key characteristics for storage
			27.1.2 Which lithium-ion chemistry should be used in grid storage?
			27.1.3 Published literature data survey and review for lithium-ion electrical energy storage
			27.1.4 The case for considering use phase
				27.1.4.1 GHG emissions associated with storing wind
			27.1.5 Net energy analysis of storing and curtailing wind resources
		27.2 Conclusion
		References
E. Environmental impacts of wind energy
	28 Climate change effects on offshore wind turbines
		28.1 Introduction and background
			28.1.1 Rising temperatures, changing times
		28.2 Climate models
			28.2.1 Comparison of CMIP5 and CMIP6 models
		28.3 Impact of climate change on offshore wind turbines
			28.3.1 Wind speed
			28.3.2 Sea ice
			28.3.3 Ice accretion
		28.4 Case studies
			28.4.1 European region
			28.4.2 Indian Ocean region
		References
		Further reading
	29 Life cycle assessment: a meta-analysis of cumulative energy demand and greenhouse gas emissions for wind energy technologies
		29.1 Introduction
		29.2 Wind energy technologies
			29.2.1 Rotor
				29.2.1.1 Hub
				29.2.1.2 Blades
			29.2.2 Nacelle
				29.2.2.1 Gearing and generator
				29.2.2.2 Foundation and cover
			29.2.3 Tower
			29.2.4 Foundation
			29.2.5 Balance of system
			29.2.6 Operation and maintenance
			29.2.7 Disposal
		29.3 Life-cycle assessment
			29.3.1 Cumulative energy demand
			29.3.2 Carbon footprint
			29.3.3 Energy return on investment
			29.3.4 Carbon return on investment
			29.3.5 Energy payback time
			29.3.6 Carbon payback time
			29.3.7 Fractional electricity reinvestment
			29.3.8 Fractional carbon emissions
		29.4 Meta-analysis
			29.4.1 Literature search
			29.4.2 Literature screening
		29.5 Results and discussion
			29.5.1 Capital energy costs
			29.5.2 Capital carbon costs
			29.5.3 Life-cycle energy costs
			29.5.4 Life-cycle carbon costs
			29.5.5 Components
			29.5.6 Trends in parameters
			29.5.7 Net energy trajectory of the global wind industry
			29.5.8 Net carbon trajectory of the global wind industry
		29.6 Conclusions
		Acknowledgments
		Appendix A: Meta-analysis results
		Appendix B: Contribution per component
		References
	30 Wind turbines and landscape
		30.1 A passion for landscape
		30.2 What is landscape?
		30.3 Changing landscape
			30.3.1 People’s opinions
		30.4 Technological advancement
		30.5 The perception of wind farms
			30.5.1 Height and size
			30.5.2 Composition
			30.5.3 Movement
		30.6 Landscapes with power generation objects
		30.7 What are the effects of wind farms on our landscape?
			30.7.1 Landscape effects
			30.7.2 Visual effects
			30.7.3 Landscape and visual effects
		30.8 Mitigation
			30.8.1 Strategic approach
		30.9 Conclusion
		References
	31 Turbulent-boundary-layer trailing-edge noise reduction technologies including porous materials
		31.1 Noise sources in a wind turbine
		31.2 Noise reduction technologies
			31.2.1 Characterization of the porous materials
			31.2.2 From porous foams to innovative metamaterials
		31.3 Conclusions
		References
	32 Global rare earth supply, life cycle assessment, and wind energy
		32.1 Background of rare earth elements
		32.2 Global rare earth elements supply
		32.3 Rare earth elements permanent magnets
		32.4 Life cycle assessment of the use of rare earth elements magnets in wind turbines
		32.5 Global wind energy projections
		32.6 Implications for future rare earth elements supply
		32.7 Conclusion
		References
	33 Short-term power prediction and downtime classification
		33.1 Introduction
		33.2 Wind turbine data
		33.3 Downtime detection
		33.4 Data preprocessing
		33.5 Understanding classification
		33.6 Statistical wind power forecasting modeling for short-term forecasting
			33.6.1 Time series analysis models
			33.6.2 Artificial intelligence models
			33.6.3 Other models
		33.7 Downtime detection and classification
		33.8 Conclusions
		References
F. Economics of wind energy and certification issues
	34 Levelized cost of energy (UK offshore wind power) drivers, challenges, opportunities and practice 2010–20
		34.1 Offshore wind power and climate change
		34.2 Levelized cost of energy
		34.3 Levelized cost of energy and the systems theory of management
		34.4 Trends in levelized cost of energy trends 2010–20
		34.5 The supra-system
			34.5.1 Enabling environment legal
			34.5.2 The Energy Act 2008
			34.5.3 The Energy Act 2011
			34.5.4 Electricity market reform
			34.5.5 2012–20
			34.5.6 2020–30
			34.5.7 2030–50
			34.5.8 The Energy Act 2013
			34.5.9 The Energy Act 2016
			34.5.10 Policy instruments
				34.5.10.1 Electricity market reform
			34.5.11 Maximizing economic recovery strategy for the United Kingdom
			34.5.12 Legal instruments
			34.5.13 Political intent
			34.5.14 Procurement environment and its changes
			34.5.15 Engineering procurement and construction contract
			34.5.16 Multicontracting
			34.5.17 New engineering contract
			34.5.18 Developments in project financing
			34.5.19 Power purchase agreements
			34.5.20 Contract for difference
			34.5.21 Strike price
			34.5.22 Technological developments
			34.5.23 Changes in rotor blades
			34.5.24 Operation and maintenance—subsea
			34.5.25 Developments in turbine design
			34.5.26 Developments in generator design
			34.5.27 Sympathetic industries
			34.5.28 Foundations and changes in foundation designs
			34.5.29 Offshore wind farm foundations
			34.5.30 Offshore wind farm foundations and installations
			34.5.31 Offshore wind farm foundations and loads
			34.5.32 Case studies in offshore wind energy
			34.5.33 Dogger bank wind farm
			34.5.34 Foundations
			34.5.35 Contract for difference
			34.5.36 Power purchase agreement
			34.5.37 Dogger bank and technology
			34.5.38 Dogger bank and levelized cost of energy
		34.6 Discussion
			34.6.1 The legal environment
			34.6.2 The commercial environment
			34.6.3 The technological environment
			34.6.4 The transformational unit in the supra-system
		References
	35 Certification of new foundations for offshore wind turbines
		35.1 Need for new types of foundations for offshore wind farm development
		35.2 De-risking of foundation based on technology readiness level
		35.3 What does technology readiness level 3 and 4 constitute in the context of foundation design
			35.3.1 Requirements of foundation testing for offshore wind turbine foundations
		35.4 Steps in the design of physical modeling
		35.5 A novel test set-up for technology readiness level studies
			35.5.1 To characterizing the dynamics features of the system (modes of vibration)
		35.6 Long-term serviceability limit state tests
		35.7 Technology readiness level example from gravity based structures
			35.7.1 Technology readiness level testing
		35.8 Technology readiness level example from monopile
		35.9 Technology readiness level example for hybrid foundation
			35.9.1 Prototype response
		35.10 Concluding remarks
		Appendix-A List of projects
		References
Index
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