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
Back Cover