Renewable and Efficient Electric Power Systems

by Masters, Gilbert M.

• ISBN13: 9781118140628
• ISBN10: 1118140621
• Edition: 2nd
• Format: Hardcover
• Copyright: 2013-06-24
• Publisher: Wiley

Summary

A solid, quantitative, practical introduction to a wide range of renewable energy systems—in a completely updated, new edition

The second edition of Renewable and Efficient Electric Power Systems provides a solid, quantitative, practical introduction to a wide range of renewable energy systems. For each topic, essential theoretical background is introduced, practical engineering considerations associated with designing systems and predicting their performance are provided, and methods for evaluating the economics of these systems are presented. While the book focuses on the fastest growing, most promising wind and solar technologies, new material on tidal and wave power, small-scale hydroelectric power, geothermal and biomass systems is introduced. Both supply-side and demand-side technologies are blended in the final chapter, which introduces the emerging smart grid. As the fraction of our power generated by renewable resources increases, the role of demand-side management in helping maintain grid balance is explored.

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. While grid-connected systems dominate the market today, off-grid systems are beginning to have a significant impact on emerging economies where electricity is a scarce commodity. Considerable attention is paid to the economics of all of these systems.

This edition has been completely rewritten, updated, and reorganized. New material has been presented both in the form of new topics as well as in greater depth in some areas. The section on the fundamentals of electric power has been enhanced, making this edition a much better bridge to the more advanced courses in power that are returning to many electrical engineering programs. 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. Realizing that many students, as well as professionals, in this increasingly important field may have modest electrical engineering backgrounds, early chapters develop the skills and knowledge necessary to understand these important topics without the need for supplementary materials.

With numerous completely worked examples throughout, the book has been designed to encourage self-instruction. The book includes worked examples for virtually every topic that lends itself to quantitative analysis. Each chapter ends with a problem set that provides additional practice. This is an essential resource for a mixed audience of engineering and other technology-focused individuals.

Author Biography

GILBERT M. MASTERS received his PhD in electrical engineering from Stanford University and has taught courses there for over three decades on energy and the environment, with an emphasis on efficiency and renewables. He is currently Professor Emeritus in the Atmosphere/Energy Program in the Department of Civil and Environmental Engineering at Stanford University. He is the author of several books on environmental engineering and energy for sustainability.

Table of Contents

PREFACE xvii

1 THE U.S. ELECTRIC POWER INDUSTRY 1

1.1 Electromagnetism: The Technology Behind Electric Power 2

1.2 The Early Battle Between Edison and Westinghouse 3

1.3 The Regulatory Side of Electric Utilities 5

1.3.1 The Public Utility Holding Company Act of 1935 5

1.3.2 The Public Utility Regulatory Policies Act of 1978 6

1.3.3 Utilities and Nonutilities 7

1.3.4 Opening the Grid to NUGs 8

1.3.5 The Emergence of Competitive Markets 9

1.4 Electricity Infrastructure: The Grid 12

1.4.1 The North American Electricity Grid 14

1.4.2 Balancing Electricity Supply and Demand 16

1.4.3 Grid Stability 20

1.4.4 Industry Statistics 21

1.5 Electric Power Infrastructure: Generation 25

1.5.1 Basic Steam Power Plants 26

1.5.2 Coal-Fired Steam Power Plants 27

1.5.3 Gas Turbines 31

1.5.4 Combined-Cycle Power Plants 32

1.5.5 Integrated Gasification Combined-Cycle Power Plants 33

1.5.6 Nuclear Power 35

1.6 Financial Aspects of Conventional Power Plants 38

1.6.1 Annualized Fixed Costs 38

1.6.2 The Levelized Cost of Energy 40

1.6.3 Screening Curves 43

1.6.4 Load Duration Curves 44

1.6.5 Including the Impact of Carbon Costs and Other Externalities 48

1.7 Summary 49

References 50

Problems 50

2 BASIC ELECTRIC AND MAGNETIC CIRCUITS 56

2.1 Introduction to Electric Circuits 56

2.2 Definitions of Key Electrical Quantities 57

2.2.1 Charge 58

2.2.2 Current 58

2.2.3 Kirchhoff’s Current Law 60

2.2.4 Voltage 61

2.2.5 Kirchhoff’s Voltage Law 63

2.2.6 Power 63

2.2.7 Energy 64

2.2.8 Summary of Principal Electrical Quantities 64

2.3 Idealized Voltage and Current Sources 65

2.3.1 Ideal Voltage Source 65

2.3.2 Ideal Current Source 66

2.4 Electrical Resistance 66

2.4.1 Ohm’s Law 66

2.4.2 Resistors in Series 68

2.4.3 Resistors in Parallel 69

2.4.4 The Voltage Divider 71

2.4.5 Wire Resistance 73

2.5 Capacitance 78

2.6 Magnetic Circuits 81

2.6.1 Electromagnetism 81

2.6.2 Magnetic Circuits 82

2.7 Inductance 85

2.7.1 Physics of Inductors 86

2.7.2 Circuit Relationships for Inductors 88

2.8 Transformers 92

2.8.1 Ideal Transformers 93

2.8.2 Magnetization Losses 96

Problems 100

3 FUNDAMENTALS OF ELECTRIC POWER 109

3.1 Effective Values of Voltage and Current 109

3.2 Idealized Components Subjected to Sinusoidal Voltages 113

3.2.1 Ideal Resistors 113

3.2.2 Idealized Capacitors 115

3.2.3 Idealized Inductors 119

3.2.4 Impedance 121

3.3 Power Factor 125

3.3.1 The Power Triangle 127

3.3.2 Power Factor Correction 129

3.4 Three-Wire, Single-Phase Residential Wiring 131

3.5 Three-Phase Systems 134

3.5.1 Balanced, Wye-Connected Systems 134

3.5.2 Delta-Connected, Three-Phase Systems 142

3.6 Synchronous Generators 143

3.6.1 The Rotating Magnetic Field 144

3.6.2 Phasor Model of a Synchronous Generator 146

3.7 Transmission and Distribution 148

3.7.1 Resistive Losses in T&D 149

3.7.2 Importance of Reactive Power Q in T&D Systems 152

3.7.3 Impacts of P and Q on Line Voltage Drop 154

3.8 Power Quality 157

3.8.1 Introduction to Harmonics 158

3.8.2 Total Harmonic Distortion 161

3.8.3 Harmonics and Overloaded Neutrals 162

3.8.4 Harmonics in Transformers 165

3.9 Power Electronics 166

3.9.1 AC-to-DC Conversion 166

3.9.2 DC-to-DC Conversions 169

3.9.3 DC-to-AC Inverters 175

3.10 Back-to-Back Voltage-Source Converter 177

References 178

Problems 178

4 THE SOLAR RESOURCE 186

4.1 The Solar Spectrum 186

4.2 The Earth’s Orbit 190

4.3 Altitude Angle of the Sun at Solar Noon 193

4.4 Solar Position at Any Time of Day 196

4.5 Sun Path Diagrams for Shading Analysis 200

4.6 Shading Analysis Using Shadow Diagrams 203

4.7 Solar Time and Civil (Clock) Time 206

4.8 Sunrise and Sunset 209

4.9 Clear-Sky Direct-Beam Radiation 210

4.10 Total Clear-Sky Insolation on a Collecting Surface 216

4.10.1 Direct Beam Radiation 216

4.10.2 Diffuse Radiation 217

4.10.3 Reflected Radiation 220

4.10.4 Tracking Systems 222

4.11 Monthly Clear-Sky Insolation 227

4.12 Solar Radiation Measurements 233

4.13 Solar Insolation Under Normal Skies 235

4.13.1 TMY Insolation on a Solar Collector 236

4.14 Average Monthly Insolation 238

References 246

Problems 247

5 PHOTOVOLTAIC MATERIALS AND ELECTRICAL CHARACTERISTICS 253

5.1 Introduction 253

5.2 Basic Semiconductor Physics 255

5.2.1 The Band-Gap Energy 256

5.2.2 Band-Gap Impact on PV Efficiency 260

5.2.3 The p–n Junction 263

5.2.4 The p–n Junction Diode 265

5.2.5 A Generic PV Cell 267

5.3 PV Materials 267

5.3.1 Crystalline Silicon 269

5.3.2 Amorphous Silicon 272

5.3.3 Gallium Arsenide 274

5.3.4 Cadmium Telluride 275

5.3.5 Copper Indium Gallium Selenide 276

5.4 Equivalent Circuits for PV Cells 277

5.4.1 The Simplest Equivalent Circuit 277

5.4.2 A More Accurate Equivalent Circuit for a PV Cell 280

5.5 From Cells to Modules to Arrays 284

5.5.1 From Cells to a Module 285

5.5.2 From Modules to Arrays 287

5.6 The PV I–V Curve Under Standard Test Conditions 288

5.7 Impacts of Temperature and Insolation on I–V Curves 291

5.8 Shading Impacts on I–V Curves 294

5.8.1 Physics of Shading 294

5.8.2 Bypass Diodes and Blocking Diodes for Shade Mitigation 299

5.9 Maximum Power Point Trackers 301

5.9.1 The Buck–Boost Converter 302

5.9.2 MPPT Controllers 305

References 309

Problems 309

6 PHOTOVOLTAIC SYSTEMS 316

6.1 Introduction 316

6.2 Behind-the-Meter Grid-Connected Systems 317

6.2.1 Physical Components in a Grid-Connected System 317

6.2.2 Microinverters 319

6.2.3 Net Metering and Feed-In Tariffs 321

6.3 Predicting Performance 322

6.3.1 Nontemperature-Related PV Power Derating 323

6.3.2 Temperature-Related PV Derating 327

6.3.3 The “Peak-Hours” Approach to Estimate PV Performance 330

6.3.4 Normalized Energy Production Estimates 333

6.3.5 Capacity Factors for PV Grid-Connected Systems 334

6.3.6 Some Practical Design Considerations 336

6.4 PV System Economics 338

6.4.1 PV System Costs 338

6.4.2 Amortizing Costs 340

6.4.3 Cash Flow Analysis 344

6.4.4 Residential Rate Structures 347

6.4.5 Commercial and Industrial Rate Structures 349

6.4.6 Economics of Commercial-Building PV Systems 351

6.4.7 Power Purchase Agreements 352

6.4.8 Utility-Scale PVs 353

6.5 Off-Grid PV Systems with Battery Storage 356

6.5.1 Stand-alone System Components 356

6.5.2 Self-regulating Modules 358

6.5.3 Estimating the Load 360

6.5.4 Initial Array Sizing Assuming an MPP Tracker 364

6.5.5 Batteries 366

6.5.6 Basics of Lead–Acid Batteries 367

6.5.7 Battery Storage Capacity 370

6.5.8 Coulomb Efficiency Instead of Energy Efficiency 373

6.5.9 Battery Sizing 375

6.5.10 Sizing an Array with No MPP Tracker 378

6.5.11 A Simple Design Template 381

6.5.12 Stand-alone PV System Costs 384

6.6 PV-Powered Water Pumping 387

6.6.1 The Electrical Side of the System 388

6.6.2 Hydraulic Pump Curves 390

6.6.3 Hydraulic System Curves 393

6.6.4 Putting it All Together to Predict Performance 396

References 399

Problems 400

7 WIND POWER SYSTEMS 410

7.1 Historical Development of Wind Power 410

7.2 Wind Turbine Technology: Rotors 415

7.3 Wind Turbine Technology: Generators 418

7.3.1 Fixed-Speed Synchronous Generators 418

7.3.2 The Squirrel-Cage Induction Generator 419

7.3.3 The Doubly-Fed Induction Generator 422

7.3.4 Variable-Speed Synchronous Generators 423

7.4 Power in the Wind 424

7.4.1 Temperature and Altitude Correction for Air Density 426

7.4.2 Impact of Tower Height 429

7.5 Wind Turbine Power Curves 433

7.5.1 The Betz Limit 433

7.5.2 Idealized Wind Turbine Power Curve 437

7.5.3 Real Power Curves 438

7.5.4 IEC Wind Turbine Classifications 441

7.5.5 Measuring the Wind 442

7.6 Average Power in the Wind 443

7.6.1 Discrete Wind Histogram 444

7.6.2 Wind Power Probability Density Functions 447

7.6.3 Weibull and Rayleigh Statistics 448

7.6.4 Average Power in the Wind with Rayleigh Statistics 450

7.6.5 Wind Power Classifications 452

7.7 Estimating Wind Turbine Energy Production 454

7.7.1 Wind Speed Cumulative Distribution Function 454

7.7.2 Using Real Power Curves with Weibull Statistics 458

7.7.3 A Simple Way to Estimate Capacity Factors 463

7.8 Wind Farms 468

7.8.1 Onshore Wind Power Potential 468

7.8.2 Offshore Wind Farms 475

7.9 Wind Turbine Economics 481

7.9.1 Annualized Cost of Electricity from Wind Turbines 482

7.9.2 LCOE with MACRS and PTC 485

7.9.3 Debt and Equity Financing of Wind Energy Systems 489

7.10 Environmental Impacts of Wind Turbines 489

References 491

Problems 492

8 MORE RENEWABLE ENERGY SYSTEMS 498

8.1 Introduction 498

8.2 Concentrating Solar Power Systems 498

8.2.1 Carnot Efficiency for Heat Engines 499

8.2.2 Direct Normal Irradiance 502

8.2.3 Condenser Cooling for CSP Systems 504

8.2.4 Thermal Energy Storage for CSP 506

8.2.5 Linear Parabolic Trough Systems 509

8.2.6 Solar Central Receiver Systems (Power Towers) 511

8.2.7 Linear Fresnel Reflectors 513

8.2.8 Solar Dish Stirling Power Systems 514

8.2.9 Summarizing CSP Technologies 518

8.3 Wave Energy Conversion 521

8.3.1 The Wave Energy Resource 521

8.3.2 Wave Energy Conversion Technology 526

8.3.3 Predicting WEC Performance 527

8.3.4 A Future for Wave Energy 529

8.4 Tidal Power 530

8.4.1 Tidal Current Power 530

8.4.2 Origin of the Tides 531

8.4.3 Estimating In-Stream Tidal Power 533

8.4.4 Estimating Tidal Energy Delivered 537

8.5 Hydroelectric Power 538

8.5.1 Hydropower Configurations 539

8.5.2 Basic Principles 541

8.5.3 Turbines 543

8.5.4 Accounting for Losses 545

8.5.5 Measuring Flow for a Micro-Hydro System 547

8.5.6 Electrical Aspects of Small-Scale Hydro 549

8.6 Pumped-Storage Hydro 550

8.7 Biomass for Electricity 553

8.8 Geothermal Power 555

References 558

Problems 559

9 BOTH SIDES OF THE METER 564

9.1 Introduction 564

9.2 Smart Grid 565

9.2.1 Automating Distribution Systems 566

9.2.2 Volt/VAR Optimization 566

9.2.3 Better Control of the Grid 568

9.2.4 Advanced Metering Infrastructure 570

9.2.5 Demand Response 571

9.2.6 Dynamic Dispatch 572

9.3 Electricity Storage 575

9.3.1 Stationary Battery Storage 575

9.3.2 Electric Vehicles and Mobile Battery Storage 577

9.4 Demand Side Management 580

9.4.1 Disincentives Caused by Traditional Ratemaking 581

9.4.2 Necessary Conditions for Successful DSM Programs 582

9.4.3 Cost-Effectiveness Measures of DSM 584

9.5 Economics of Energy Efficiency 585

9.5.1 Energy Conservation Supply Curves 586

9.5.2 Greenhouse Gas Abatement Curves 588

9.6 Combined Heat and Power Systems 591

9.6.1 CHP Efficiency Measures 591

9.6.2 Economics of Combined Heat and Power 593

9.7 Cogeneration Technologies 596

9.7.1 HHV and LHV 596

9.7.2 Microturbines 598

9.7.3 Reciprocating Internal Combustion Engines 600

9.8 Fuel Cells 602

9.8.1 Historical Development 603

9.8.2 Basic Operation of Fuel Cells 604

9.8.3 Fuel Cell Thermodynamics: Enthalpy 605

9.8.4 Entropy and the Theoretical Efficiency of Fuel Cells 609

9.8.5 Gibbs Free Energy and Fuel Cell Efficiency 612

9.8.6 Electrical Output of an Ideal Cell 613

9.8.7 Electrical Characteristics of Real Fuel Cells 615

9.8.8 Types of Fuel Cells 616

9.8.9 Hydrogen Production 620

References 623

Problems 624

APPENDIXA ENERGY ECONOMICS TUTORIAL 629

A.1 Simple Payback Period 629

A.2 Initial (Simple) Rate of Return 630

A.3 The Time Value of Money and Net Present Value 630

A.4 Internal Rate of Return 633

A.5 Net Present Value with Fuel Escalation 635

A.6 IRR with Fuel Escalation 637

A.7 Annualizing the Investment 638

A.8 Levelized Busbar Costs 639

A.9 Cash-Flow Analysis 643

APPENDIXB USEFUL CONVERSION FACTORS 645

APPENDIXC SUN-PATH DIAGRAMS 649

APPENDIXD HOURLY CLEAR-SKY INSOLATION TABLES 653

APPENDIX E MONTHLY CLEAR-SKY INSOLATION TABLES 663

APPENDIX F SHADOW DIAGRAMS 667

APPENDIXG SOLAR INSOLATION TABLES BY CITY 670

INDEX 683