Wind Energy Explained: Theory, Design and Application

By Paul Gipe

It’s been many years since the publication of new engineering texts on wind energy. But in 2001 a flood of new books in English began flowing from publishers: two substantial volumes by John Wiley & Sons’ UK bureau alone, two English translations of German works, two English language works by Dutch authors, and a recent work by a Canadian on his country’s Darrieus program.

It’s been even longer since a new technical work by authors in the United States. Not since David Spera’s Wind Turbine Technology in 1994 has there been as complete a book on wind energy as Wind Energy Explained.

Wind Energy Explained grew out of course notes for training engineering students at the University of Massachusetts at Amherst where all three authors teach. Their wind energy engineering course has been offered since the mid 1970s and is one of the few remaining wind engineering courses in North America.

Jim Manwell and John McGowan, two of the book’s three authors, are old wind hands. (I once came across a report written by Manwell circa 1980 when I resided at the Folkecenter for Renewable Energy in Denmark.) They are well-known in the American wind industry for their work keeping UMass’ Renewable Energy Research Laboratory alive when similar programs were closing across the country during the Reagan years.


Disclosure: My book Wind Energy Comes of Age is published by John Wiley & Sons (US), and the rights to it were briefly held by John Wiley & Sons (UK).

As a course book, Wind Energy Explained is replete with problems at the end of the book for engineering students to tackle. Best of all, the answers can be found at say the publisher. And in a bow to modern publishing trends, Wiley also offers the book for download by registered academic purchasers.

Though intended as a text for UMass’ wind engineering course, the book will be invaluable for anyone working in a technical field related to wind energy. There is sufficient introductory material in each chapter for those who want a taste of a topic and don’t have the time to wade through the derivations.

With the exception of the Canadian book, all the modern texts on wind energy are European in origin. Wind Energy Explained, while written by American authors for the American market was commissioned, edited, and produced in Europe.

John Wiley & Sons’ European publishing arm boldly plunged into the wind energy field in the late 1990s when American publishers were dumping their renewable energy titles. The wind industry had clearly shifted to Europe and Wiley followed the market.

At one time Wiley’s UK office had at least three technical books on wind energy in the pipeline. Both Wind Energy Explained and Wind Energy Handbook are very big and very complicated to produce. Wind Energy Handbook was written by British authors. Wiley UK also launched the English language version of Eric Hau’s book on the design of large wind turbines as well as the Wind Energy Journal, one of only two peer-reviewed journals on wind energy.

Wiley offers Wind Energy Explained at a surprisingly competitive price for a book of this size. Books half its size published by Wiley in New York sell for nearly twice the price of the British publication.

For those working day-to-day in the industry, the most useful chapters in Wind Energy Explained may be those on integration of wind turbines into both small (UMass has extensive experience with wind-diesel systems) and large networks, and on environmental issues surrounding wind energy.

The chapter on environmental issues includes a comprehensive introduction on how bird kills by wind turbines are evaluated, sources of noise from wind turbines and how to calculate emission strength, how to weigh visual resources and wind’s influence on them, as well as sections on electromagnetic interference and public safety. They even include a brief explanation of shadow flicker, a topic foreign to many Americans. There is also a good section on offshore wind development.

Wind Energy Explained: Theory, Design and Application, J. F. Manwell, J. G. McGowan, A. L. Rogers, ISBN: 0-471-49972-2, cloth, US$70.00, 590 pages, 2002. Available from John Wiley & Sons, Baffins Lane, Chichester, West Sussex, PO19 8SQ, United Kingdom, +44 12 43 77 97 77,,


1 Introduction: Modern Wind Energy and its Origins
1.1 Modern Wind Turbines
1.2 History of Wind Energy References
2 Wind Characteristics and Resources
2.1 Introduction
2.2 General Characteristics of the Wind Resource
2.3 Characteristics of the Atmospheric Boundary Layer
2.4 Wind Data Analysis and Resource Estimation
2.5 Wind Turbine Energy Production Estimates Using Statistical Techniques
2.6 Overview of Available Resource Assessment Data
2.7 Wind Measurements and Instrumentation
2.8 Advanced Topics References
3 Aerodynamics of Wind Turbines
3.1 General Overview
3.2 One-Dimensional Momentum Theory and the Betz Limit
3.3 Ideal Horizontal Axis Wind Turbine with Wake Rotation
3.4 Airfoils and General Concepts of Aerodynamics
3.5 Momentum Theory and Blade Element Theory
3.6 Blade Shape for Ideal Rotor without Wake Rotation
3.7 General Rotor Blade Shape Performance Prediction
3.8 Blade Shape for Optimum Rotor with Wake Rotation
3.9 Generalized Rotor Design Procedure
3.10 Simplified HAWT Rotor Performance Calculation Procedure
3.11 Effect of Drag and Blade Number on Optimum Performance
3.12 Advanced Aerodynamic Topics References
4 Mechanics and Dynamics
4.1 General Background
4.2 General Principles
4.3 Wind Turbine Rotor Dynamics
4.4 Detailed and Specialized Dynamic Models References
5 Electrical Aspects of Wind Turbines
5.1 Overview
5.2 Basic Concepts of Electric Power
5.3 Power Transfonners 5.4 Electrical Machines
5.5 Power Converters
5.6 Ancillary electrical equipment References
6 Wind Turbine Design
6.1 Overview
6.2 Design Procedure
6.3 Wind Turbine Topologies
6.4 Materials
6.5 Machine Elements
6.6 Wind Turbine Loads
6.7 Wind Turbine Subsystems and Components
6.8 Design Evaluation
6.9 Power Curve Prediction References
7 Wind Turbine Control
7.1 Introduction
7.2 Overview of Wind Turbine Control Systems
7.3 Typical Grid-connected Turbine Operation
7.4 Supervisory Control Overview and Implementation
7.5 Dynamic Control Theory and Implementation References
8 Wind Turbine Siting, System Design and Integration
8.1 General Overview
8.2 Wind Turbine Siting
8.3 Installation and Operation Issues
8.4 Wind Farms
8.5 Wind Turbines and Wind Farms in Electric Grids
8.6 Offshore Wind Fanns
8.7 Operation in Severe Climates
8.8 Hybrid Electrical Systems References
9 Wind Energy System Economics
9.1 Introduction
9.2 Overview of Economic Assessment of Wind Energy Systems
9.3 Capital Costs of Wind Energy Systems
9.4 Operation and maintenance costs
9.5 Value of Wind Energy
9.6 Economic Analysis Methods
9.7 Wind Energy Market Considerations References
10 Wind Energy Systems: Environmental Aspects and Impacts
10.1 Introduction
10.2 Avian Interaction with Wind Turbines
10.3 Visual Impact of Wind Turbines
10.4 Wind Turbine Noise
10.5 Electromagnetic Interference Effects
10.6 Land-use environmental impacts
10.7 Other Environmental Considerations References