PREFACE: This book provides a solid, quantitative, practical introduction to a wide range of renewable energy systems. For each topic, the theoretical background is introduced, practical engineering considerations associated with designing systems and predicting their performance are provided, and methods to evaluate the economics of these systems are presented. While more attention is paid to the fastest growing, most promising, wind and solar technologies, the book also introduces tidal and wave power, geothermal, biomass, hydroelectric power, and electricity storage technologies. Both supply-side and demand-side technologies are blended in the final chapter, which introduces the coming smart grid.
The book is intended for a mixed audience of engineering and other technology-focused individuals. The course I teach at Stanford, for example, has no prerequisites. About half the students are undergraduate and half are graduate students. Almost all are from engineering and natural science departments, with a growing number of business students. The book has been designed to encourage self-teaching by providing numerous, completely worked examples throughout. Nearly every topic that lends itself to quantitative analysis is illustrated with such examples. Each chapter ends with a set of problems that provide added practice for the student, which should also facilitate the preparation of homework assignments by the instructor.
This new edition has been completely rewritten, updated and reorganized. A considerable amount of new material is presented, both in the form of new topics as well as greater depth in some areas. New topics include wave and tidal power, pumped storage, smart grid, and geothermal power. The section on fundamentals of electric power is strengthened to make this book a much better bridge to advanced courses in power in electrical engineering departments.
This includes an introduction to phasor notation, more emphasis on reactive power as well as real power, more on power converter and inverter electronics, and more material on generator technologies. Renewable energy systems have become mainstream technologies and are now, literally, big business. Throughout this edition, more depth has been provided on the financial analysis of large-scale conventional and renewable energy projects.
The book consists of three major sections:
I. Background material on the electric power industry (Chapters 1, 2, 3). II. Focus on photovoltaics (PVs) and wind power systems (Chapters 4, 5, 6, 7). III. Other renewables, energy efficiency, and the smart grid (Chapters 8 and 9) I. BACKGROUND (Chapters 1, 2, 3): The context for renewable energy systems is provided by an introduction to the electric power industry (Chapter 1), including conventional power plant technologies, the regulatory and operational sides of the grid itself, along with financial aspects such as levelized cost of generation. For users who are new to basic electrical components and circuits, or who need a quick review, Chapter 2 provides sufficient coverage to allow any technical student to come up to speed quickly on those fundamentals.
While many students already have some electricity background and can skip Chapter 2, most have not had a course on electric power, which is the subject of Chapter 3. In fact, it is my impression that many engineering schools that deemphasized electric power in the past are experiencing a new surge of interest in this field. Chapter 3 provides non-electrical-engineering students the background essential for success in more advanced electrical power courses.
II. PHOTOVOLTAICS AND WIND POWER (Chapters 4, 5, 6, 7):
These chapters are the heart of the book. Chapter 4 covers the solar resource, including solar angles, shading problems, clear-sky solar intensity, direct and indirect portions of solar irradiation (important distinctions for concentrating solar technologies), and how to work with real hour-by-hour, typical meteorological year (TMY) solar data for a given location.
Chapter 5 introduces photovoltaic (PV) materials and the electrical characteristics of cells, modules, and arrays. With this background, students can appreciate the dramatic impacts of shading on PV performance as well as how modern electronics can help mitigate those impacts.
Chapter 6 is on PV systems, including sizing, and predicting performance for grid-connected, utility-scale and net-metered rooftop systems, as well as off-grid stand-alone systems with battery storage. Grid-connected systems dominate the market today, while off-grid systems, including microgrid systems, are beginning to have significant impacts in emerging economies where electricity is a scarce commodity. Considerable attention is paid to the economics of all PV systems.
Chapter 7 provides an extensive analysis of wind power systems, including statistical characterizations of wind resources, emerging wind power technologies, and combining the two to predict turbine performance. Wind power currently dominates the renewables market, with billions of dollars of investment money flowing into that sector, so considerable attention is paid in this chapter to the financial analysis of such investments.
III. OTHER RENEWABLES AND THE SMART GRID (Chapters 8, 9):
Chapter 8 introduces concentrating solar power systems, including their potential to include thermal storage to provide truly dispatchable electric power. Two emerging ocean power technologies are described: tidal power and wave power.
These show considerable promise in part because their variable power outputs are somewhat more predictable than those for wind and solar systems. Hydroelectric power, including micro-hydro systems (again for emerging economies), and pumped storage systems to provide backup power for other variable renewables are described. Finally, biomass for electricity and geothermal systems are introduced.
Chapter 9 is titled “Both Sides of the Meter” and describes the range of issues encountered when variable renewables interact with demand-responsive loads. It begins with the smart grid, including advanced metering infrastructure, technologies that will provide better control of the grid, and interactions with loads that can be controlled to accommodate variations in supply-side resources. The role of electricity storage, including battery storage in electric vehicles, is introduced. Demand-side management, more efficient use of electricity, fuel cells, and other combined heat and power systems are all critical components in balancing our future supply/demand equation.
Finally, the book includes a number of appendices, including Appendix A, a brief energy-economics tutorial. The others provide assorted useful data for system analysis. This book has been in the making for over four decades, beginning with the impact that Denis Hayes and Earth Day 1970 had in shifting my career from semiconductors and computer logic into environmental engineering. Then it was Amory Lovins’ groundbreaking paper “The Soft Energy Path: The Road Not Taken?” (Foreign Affairs, 1976) that focused my attention on the relationship between energy and environment and the important roles that renewables and efficiency must play in meeting the coming challenges. The penetrating analyses of Art Rosenfeld at the University of California, Berkeley, and the astute political perspectives of Ralph Cavanagh at the Natural Resources Defense Council have been constant sources of guidance and inspiration. These and other trailblazers have illuminated the path, but it has been the challenging, committed, enthusiastic students in my Stanford classes who have kept me invigorated, excited, and energized over the years, and I am deeply indebted to them for their stimulation and friendship. Finally, I owe a special debt of gratitude to my long-time friend and colleague, Jane Woodward, for her generosity and support, which enables me to keep on trucking in this field that I love. Gilbert M. Masters