Wind Resource Assessment: A Practical Guide to Developing a Wind Project

A practical, authoritative guide to the assessment of wind resources for utility-scale wind projects—authored by a team of experts from a leading renewable energy consultancy

The successful development of wind energy projects depends on an accurate assessment of where, how often, and how strongly the wind blows. A mistake in this stage of evaluation can cause severe financial losses and missed opportunities for developers, lenders, and investors.

Wind Resource Assessment: A Practical Guide to Developing a Wind Project shows readers how to achieve a high standard of resource assessment, reduce the uncertainty associated with long-term energy performance, and maximize the value of their project assets. Beginning with the siting, installation, and operation of a high-quality wind monitoring program, this book continues with methods of data quality control and validation, extrapolating measurements from anemometer height to turbine height, adjusting short-term observations for historical climate conditions, and wind flow modeling to account for terrain and surface conditions.

In addition, Wind Resource Assessment addresses special topics such as:

• Worker safety

• Data security

• Remote sensing technology (sodar and lidar)

• Offshore resource assessment

• Impacts of climate change

• Uncertainty estimation

• Plant design and energy production estimatio

Filled with important information ranging from basic fundamentals of wind to cutting-edge research topics, and accompanied by helpful references and discussion questions, this comprehensive text—designed for an international audience—is a vital reference that promotes consistent standards for wind assessment across the industry.

This is a practical, authoritative guide to the siting and installation of a high-quality wind energy project, providing analytical methods for assessing the wind resource. The first half of the book describes the several stages of carrying out a wind-monitoring campaign, addressing such topics as worker safety, data security, and advanced remote sensing technology. The second describes the assessment methods. It also addresses cutting-edge research topics such as possible impacts of climate change on wind resources and the strengths and weaknesses of various atmospheric modeling approaches. Professionals in industry—such as planners, managers, and installers—as well as resource analysts, federal program managers, and students will rely on this resource.

Michael C. Brower, PhD, editor and lead author, is Chief Technical Officer of AWS Truepower, LLC, where he leads product development and helps ensure quality and standards across the company. A physicist and prominent expert in wind energy, he has led numerous assessments of utility-scale wind projects around the world. He is also known for his contributions to wind flow modeling and short-term wind forecasting. His coauthors are a team of experts in meteorology, engineering, and modeling who have collectively assessed over 60,000 MW of wind plant capacity.

Preface xv

1. Introduction 1

1.1 Where do Winds Come From? 2

1.2 Key Characteristics of the Wind 4

1.3 Wind Power Plants 6

1.4 Purpose and Organization of this Book 9

1.5 Questions for Discussion 10

PART 1 Wind Monitoring 13

2. Overview of a Wind Resource Assessment Campaign 15

2.1 Site Identification 16

2.2 Resource Monitoring 16

2.3 Wind Resource Analysis 20

3. Siting a Wind Project 23

3.1 Site Selection 23

3.2 Regional Wind Resource Information 25

3.3 Field Surveys 29

3.4 Tower Placement 30

3.5 Permitting for Wind Monitoring 33

3.6 Land Lease Agreements 34

3.7 Questions for Discussion 35

4. Monitoring Station Instrumentation and Measurements 37

4.1 Basic Measurements 37

4.2 Additional Measurements 45

4.3 Recorded Parameters and Sampling Intervals 49

4.4 Data Loggers 50

4.5 Data Storage Devices 51

4.6 Data Transfer Equipment 52

4.7 Power Sources 55

4.8 Towers and Sensor Support Hardware 56

4.9 Wiring 57

4.10 Measurement System Accuracy and Reliability 58

4.11 Questions for Review and Discussion 59

5. Installation of Monitoring Stations 61

5.1 Equipment Procurement 61

5.2 Equipment Acceptance Testing and Field Preparation 62

5.3 Installation Team 64

5.4 Safety 64

5.5 Determination of True North 65

5.6 Tower Installation 66

5.7 Sensor and Equipment Installation 70

5.8 Site Commissioning 80

5.9 Documentation 81

5.10 Cost and Labor Estimates 81

5.11 Questions for Discussion 84

6. Station Operation and Maintenance 87

6.1 Site Visits 88

6.2 Operation and Maintenance Procedures 88

6.3 Documentation 92

6.4 Spare Parts Inventory 93

6.5 Questions for Discussion 93

7. Data Collection and Handling 99

7.1 Raw Data Storage 99

7.2 Data Retrieval 101

7.3 Data Retrieval Frequency 101

7.4 Data Protection and Storage 101

7.5 Documentation 102

7.6 Questions for Discussion 103

8. Ground-Based Remote Sensing Systems 105

8.1 Sodar 106

8.2 Lidar 108

8.3 Remote Sensing Campaign Design and Siting 109

8.4 Data Collection and Processing 110

8.5 Comparisons with Conventional Anemometry 111

8.6 Questions for Discussion 113

PART 2 Data Analysis and Resource Assessment 115

9. Data Validation 117

9.1 Data Conversion 118

9.2 Data Validation 119

9.3 Post-Validation Adjustments 125

9.4 Data Substitution and Averaging 127

9.5 Questions for Discussion 128

10. Characterizing the Observed Wind Resource 130

10.1 Summarizing the Observed Wind Resource 130

10.2 Questions for Discussion 141

11. Estimating the Resource at Hub Height 143

11.1 Wind Speed 143

11.2 Time-Varying Speeds and Speed Distributions 150

11.3 Other Parameters 151

11.4 Questions for Discussion 152

12. The Climate Adjustment Process 155

12.1 Is the Wind Climate Stable? 156

12.2 Requirements for Accurate MCP 159

12.3 Sources of Reference Data 166

12.4 The Target–Reference Relationship 170

12.5 Questions for Discussion 174

13. Wind Flow Modeling 178

13.1 Types of Wind Flow Models 179

13.2 Application of Numerical Wind Flow Models 189

13.3 Questions for Discussion 191

14. Offshore Resource Assessment 195

14.1 Nature of the Offshore Wind Environment 197

14.2 Wind Resource Monitoring Systems 201

14.3 Operations and Maintenance of Offshore Systems 212

14.4 Satellite-Based Microwave Sensors 213

15. Uncertainty in Wind Resource Assessment 220

15.1 Measurement Uncertainty 221

15.2 Historical Wind Resource 221

15.3 Future Wind Resource 223

15.4 Wind Shear 224

15.5 Wind Flow Modeling Uncertainty 225

15.6 Combining Uncertainties 226

15.7 Questions for Discussion 230

16. Plant Design and Energy Production Estimation 233

16.1 Plant Design Software 233

16.2 Setting up the Project 235

16.3 Wind Resource Data 237

16.4 Selecting a Turbine 239

16.5 Designing and Optimizing a Turbine Layout 243

16.6 Gross and Net Energy Production 244

16.7 Special Topics 248

16.8 Questions for Discussion 256

Appendix A. Wind Resource Assessment Equipment Vendors 260

Wind Resource Assessment Equipment 261

Appendix B. Selected Source of GIS Data 263

Sources of GIS Data Related to Wind Resource Assessment 263

Index 265