About the Authors xv
1 The US 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 6
1.3.2 The Public Utility Regulatory Policies Act of 1978 7
1.3.3 Utilities and Nonutility Generators 8
1.3.4 Opening the Grid to NUGs 9
1.3.5 The Emergence of Competitive Markets 11
1.4 Electricity Infrastructure: The Grid 15
1.4.1 The North American Electricity Grid 17
1.4.2 Balancing Electricity Supply and Demand 18
1.4.3 Grid Stability 23
1.4.4 Industry Statistics 27
1.5 Electric Power Infrastructure: Generation 32
1.5.1 Basic Steam Power Plants 33
1.5.2 Coal-Fired Steam Power Plants 34
1.5.3 Gas Turbines 38
1.5.4 Combined-Cycle Power Plants 39
1.5.5 Integrated Gasification Combined-Cycle Power Plants (IGCC) 40
1.5.6 Nuclear Power 42
1.6 Financial Aspects of Conventional Power Plants 46
1.6.1 Annualized Fixed Costs 46
1.6.2 The Levelized Cost of Energy (LCOE) 48
1.6.3 Screening Curves 51
1.6.4 Load Duration Curves 52
1.6.5 Including the Impact of Carbon Costs and Other Externalities 56
1.7 Summary 58
Problems 58
References 63
2 Basic Electric and Magnetic Circuits 69
2.1 Introduction to Electric Circuits 69
2.2 Definitions of Key Electrical Quantities 70
2.2.1 Charge 70
2.2.2 Current 71
2.2.3 Kirchhoff’s Current Law 73
2.2.4 Voltage 74
2.2.5 Kirchhoff’s Voltage Law 75
2.2.6 Power 76
2.2.7 Energy 76
2.2.8 Summary of Principal Electrical Quantities 77
2.3 Idealized Voltage and Current Sources 77
2.3.1 Ideal Voltage Source 78
2.3.2 Ideal Current Source 79
2.4 Electrical Resistance 79
2.4.1 Ohm’s Law 79
2.4.2 Resistors in Series 80
2.4.3 Resistors in Parallel 81
2.4.4 The Voltage Divider 83
2.4.5 Wire Resistance 85
2.5 Capacitance 90
2.6 Magnetic Circuits 93
2.6.1 Electromagnetism 93
2.6.2 Magnetic Circuits 94
2.7 Inductance 98
2.7.1 Physics of Inductors 98
2.7.2 Circuit Relationships for Inductors 100
2.8 Transformers 104
2.8.1 Ideal Transformers 104
2.8.2 Magnetization Losses 108
Problems 112
3 Fundamentals of Electric Power 117
3.1 Effective Values of Voltage and Current 117
3.2 Idealized Components Subjected to Sinusoidal Voltages 121
3.2.1 Ideal Resistors 121
3.2.2 Idealized Capacitors 123
3.2.3 Idealized Inductors 126
3.2.4 Impedance 128
3.3 Power Factor 132
3.3.1 The Power Triangle 134
3.3.2 Power Factor Correction 135
3.4 Three-Wire, Single-Phase Residential Wiring 138
3.5 Three-Phase Systems 141
3.5.1 Balanced, Wye-Connected Systems 141
3.5.2 Delta-Connected, Three-Phase Systems 148
3.6 Synchronous Generators 149
3.6.1 The Rotating Magnetic Field 151
3.6.2 Phasor Model of a Synchronous Generator 153
3.7 Transmission and Distribution 155
3.7.1 Resistive Losses in T&D 156
3.7.2 Importance of Reactive Power Q in T&D Systems 159
3.7.3 Impacts of P and Q on Line Voltage Drop 161
3.8 Power Quality 164
3.8.1 Introduction to Harmonics 165
3.8.2 Total Harmonic Distortion 169
3.8.3 Harmonics and Overloaded Neutrals 169
3.8.4 Harmonics in Transformers 172
3.9 Power Electronics 173
3.9.1 AC-to-DC Conversion 173
3.9.2 DC-to-DC Conversions 176
3.9.3 DC-to-AC Inverters 182
3.10 Back-To-Back Voltage-Source Converter 184
Problems 185
References 192
4 The Solar Resource 193
4.1 The Solar Spectrum 193
4.2 The Earth’s Orbit 197
4.3 Altitude Angle of the Sun at Solar Noon 200
4.4 Solar Position at Any Time of Day 203
4.5 Sun Path Diagrams for Shading Analysis 207
4.6 Shading Analysis Using Shadow Diagrams 210
4.7 Solar Time and Civil (Clock) Time 213
4.8 Sunrise and Sunset 216
4.9 Clear-Sky Direct-Beam Radiation 219
4.10 Total Clear-Sky Insolation on a Collecting Surface 223
4.10.1 Direct Beam Radiation 223
4.10.2 Diffuse Radiation 225
4.10.3 Reflected Radiation 227
4.10.4 Tracking Systems 229
4.11 Monthly Clear-Sky Insolation 237
4.12 Solar Radiation Measurements 240
4.13 Solar Insolation Under Normal Skies 245
4.13.1 TMY Insolation on a Solar Collector 245
4.14 Average Monthly Insolation 248
Problems 256
References 261
5 Photovoltaic Materials and Electrical Characteristics 263
5.1 Introduction 263
5.2 Basic Semiconductor Physics 266
5.2.1 The Band-Gap Energy 267
5.2.2 Band-Gap Impact on PV Efficiency 271
5.2.3 The p–n Junction 274
5.2.4 The p–n Junction Diode 277
5.2.5 A Generic PV Cell 279
5.3 PV Materials 280
5.3.1 Crystalline Silicon 280
5.3.2 Amorphous Silicon 284
5.3.3 Gallium Arsenide 286
5.3.4 Cadmium Telluride 287
5.3.5 Copper Indium Gallium Selenide (CIGS) 288
5.3.6 Emerging PVs 289
5.4 Equivalent Circuits for PV Cells 290
5.4.1 The Simplest Equivalent Circuit 291
5.4.2 A More Accurate Equivalent Circuit for a PV Cell 294
5.5 From Cells to Modules to Arrays 298
5.5.1 From Cells to a Module 299
5.5.2 From Modules to Arrays 301
5.6 The PV I–V Curve Under Standard Test Conditions 302
5.7 Impacts of Temperature and Insolation on I–V Curves 305
5.8 Shading Impacts on I–V Curves 307
5.8.1 Physics of Shading 308
5.8.2 Bypass Diodes and Blocking Diodes for Shade Mitigation 312
5.9 Maximum Power Point Trackers 315
5.9.1 The Buck–Boost Converter 315
5.9.2 MPPT Controllers 319
Problems 322
References 328
6 Photovoltaic Systems 331
6.1 Introduction 331
6.2 Physical Components in a Behind-the-Meter, Grid-Connected System 331
6.2.1 Microinverters 334
6.2.2 Using Space Strategically: Securing Solar Panels with Racking and Mounting Systems 336
6.3 Predicting Performance 339
6.3.1 Non Temperature-Related PV Power Derating 340
6.3.2 Temperature-Related PV Derating 345
6.3.3 The “Peak-Hours” Approach to Estimate PV Performance 347
6.3.4 Normalized Energy Production Estimates 350
6.3.5 Capacity Factors for PV Grid-Connected Systems 352
6.3.6 Practical Design Considerations 353
6.3.7 Codes and Requirements 356
6.4 PV System Economics 357
6.4.1 Net Metering and Feed-in Tariffs 357
6.4.2 PV System Costs 359
6.4.3 Amortizing Costs 362
6.4.4 Cash Flow Analysis 367
6.4.5 Residential Rate Structures 369
6.4.6 Commercial and Industrial Rate Structures 372
6.4.7 Economics of PV Systems on Commercial Buildings 374
6.4.8 Power Purchase Agreements 375
6.4.9 Utility-Scale PVs 376
6.5 Summary of System Design for Solar PV on Buildings 378
Problems 380
References 386
7 Wind Power Systems 389
7.1 Historical Development of Wind Power 389
7.2 Wind Turbine Technology: Rotors 395
7.3 Wind Turbine Technology: Generators 398
7.3.1 Fixed-Speed Synchronous Generators 399
7.3.2 The Squirrel-Cage Induction Generator 400
7.3.3 The Doubly Fed Induction Generator 402
7.3.4 Variable-Speed Synchronous Generators 403
7.4 Power in the Wind 405
7.4.1 Temperature and Altitude Correction for Air Density 407
7.4.2 Impact of Tower Height 410
7.5 Wind Turbine Power Curves 413
7.5.1 The Betz Limit 413
7.5.2 Idealized Wind Turbine Power Curve 417
7.5.3 Real Power Curves 418
7.5.4 IEC Wind Turbine Classifications 422
7.5.5 Measuring the Wind 423
7.6 Average Power in the Wind 424
7.6.1 Discrete Wind Histogram 424
7.6.2 Wind Power Probability Density Functions 428
7.6.3 Weibull and Rayleigh Statistics 429
7.6.4 Average Power in the Wind with Rayleigh Statistics 431
7.6.5 Wind Power Maps and Classifications 433
7.7 Estimating Wind Turbine Energy Production 435
7.7.1 Wind Speed Cumulative Distribution Function 435
7.7.2 Using Real Power Curves with Weibull Statistics 439
7.7.3 A Simple Way to Estimate Capacity Factors 445
7.8 Wind Farms 450
7.8.1 Onshore Wind Power Potential 450
7.8.2 Curtailment and Transmission 458
7.8.3 Offshore Wind Farms 458
7.9 Wind Turbine Economics 465
7.9.1 Annualized Cost of Electricity from Wind Turbines 465
7.9.2 LCOE with MACRS and PTC 468
7.9.3 Debt and Equity Financing of Wind Energy Systems 473
7.10 Environmental Impacts of Wind Turbines 473
Problems 476
References 481
8 More Renewable Energy Systems for Electricity Generation 487
8.1 Introduction 487
8.2 Concentrating Solar–Thermal Power Systems 487
8.2.1 Carnot Efficiency for Heat Engines 488
8.2.2 Direct Normal Irradiance (DNI) 491
8.2.3 Condenser Cooling for CSP Systems 494
8.2.4 Thermal Energy Storage for CSP 495
8.2.5 Linear Parabolic Trough Systems 499
8.2.6 Solar Central Receiver Systems (Power Towers) 501
8.2.7 Linear Fresnel Reflectors (LFRs) 504
8.2.8 Solar Dish-Stirling (Dish/Engine) Power Systems 505
8.2.9 Summarizing CSP Technologies 509
8.3 Wave Energy Conversion 512
8.3.1 The Wave Energy Resource 512
8.3.2 Wave Energy Conversion Technology 517
8.3.3 Predicting WEC Performance 518
8.3.4 A Future for Wave Energy 520
8.4 Tidal Power 521
8.4.1 Tidal Current Power 522
8.4.2 Origin of the Tides 523
8.4.3 Estimating In-stream Tidal Power 525
8.4.4 Estimating Tidal Energy Delivered 528
8.5 Hydroelectric Power 531
8.5.1 Hydropower Configurations 532
8.5.2 Basic Principles 534
8.5.3 Turbines 536
8.5.4 Accounting for Losses 538
8.5.5 Measuring Flow for a Micro-Hydro System 541
8.5.6 Electrical Aspects of Small-scale Hydro 542
8.6 Pumped Storage Hydro 543
8.7 Biomass for Electricity 546
8.7.1 Is Biomass a Carbon-Neutral Resource? 547
8.7.2 Fuel Types for Electricity Generation 548
8.8 Geothermal Power 551
8.8.1 Resource Sites 552
8.8.2 Energy Extraction 553
8.8.3 Summary of Geothermal Power 554
Problems 556
References 560
9 Mainstreaming Energy Efficiency as a Renewable Resource 569
9.1 Introduction 569
9.2 Efficiency Versus Conservation 570
9.3 Energy Efficiency at Different Scales 571
9.3.1 Energy Efficiency of Countries 571
9.3.2 Energy Efficiency of Companies 572
9.3.3 Energy Efficiency of Cities and Buildings 572
9.3.4 Energy Efficiency of Equipment 573
9.4 Benefits of Energy Efficiency 575
9.5 Building Energy Efficiency 576
9.5.1 Building Design: Passive and Active Strategies 576
9.5.2 Efficient Operations: Commissioning, Monitoring, and Energy Management Systems 585
9.5.3 Integrating Renewable Energy 585
9.6 Policy and Regulation for Energy-Efficient Buildings 586
9.7 Smart Grid 588
9.7.1 Automating Distribution Systems 589
9.7.2 Volt/VAR Optimization 589
9.7.3 Better Control of the Grid 591
9.7.4 Advanced Metering Infrastructure (AMI) 593
9.7.5 Demand Response (DR) 594
9.7.6 Dynamic Dispatch 596
9.8 Electricity Storage 598
9.9 Establishing Demand-Side Management Programs 598
9.9.1 Disincentives Caused by Traditional Ratemaking 600
9.9.2 Necessary Conditions for Successful DSM Programs 601
9.9.3 Cost-Effectiveness Measures of DSM 603
9.10 Economics of Energy Efficiency 605
9.10.1 Energy Conservation Supply Curves 605
9.11 Reducing Carbon: Greenhouse Gas Abatement Curves 608
9.12 District Heating and District Cooling 610
9.13 Combined Heat and Power Systems for Buildings and Districts 612
9.13.1 CHP Efficiency Measures 612
9.13.2 Economics of Combined Heat and Power (CHP) 614
9.14 Technologies Used in CHP/Cogeneration Plants 617
9.14.1 HHV and LHV 617
9.14.2 Microturbines 619
9.14.3 Reciprocating Internal Combustion Engines 621
9.15 Data and Energy 623
9.15.1 Building Operations 624
9.15.2 Multi-Building Operations and Planning 625
9.15.3 City Climate Action 625
9.15.4 Data Centers and the IT Sector 626
Problems 629
References 633
10 Energy Storage: Batteries, Fuel Cells, and Hydrogen 639
10.1 Ensuring Resource Adequacy 640
10.2 The Need for Energy Storage 641
10.3 Battery Basics 642
10.4 Lithium-Ion Batteries 644
10.5 Emerging Battery Technologies 646
10.5.1 Silicon Anodes 646
10.5.2 Lithium-Metal Batteries 647
10.5.3 Solid-State Batteries 648
10.6 Beyond the Cell: Producing Battery Modules and Packs 648
10.6.1 Thermal Safety 651
10.7 The Big Picture: Diverse Applications for Li-Ion Batteries 652
10.8 Lead–Acid Batteries 654
10.8.1 Basics of Lead–Acid Batteries 654
10.8.2 Battery Chemistry of Lead–Acid Batteries 656
10.9 Battery Storage Capacity 6.5.7 659
10.10 Coulombic Efficiency Instead of Energy Efficiency 663
10.11 Battery Systems for Buildings 664
10.11.1 Commercial Buildings 666
10.11.2 Operating to Maximize Cost Savings and Financial Benefits 668
10.11.3 Incentives and Regulations for Energy Storage 669
10.12 Carbon Savings 670
10.13 Utility-Scale Batteries 674
10.13.1 Flow Batteries 678
10.13.2 Iron–Air Batteries for Long-Duration Energy Storage 681
10.13.3 Sodium–Sulfur Batteries 682
10.14 Dynamic Dispatch and Grid Storage with Electric Vehicle Fleets 682
10.15 Hydrogen, Fuel Cells, Electrolyzers, and Prospects for Long-Term Storage 686
10.15.1 Fuel Cells 687
10.15.2 Historical Development 688
10.15.3 Basic Operation of Fuel Cells 688
10.15.4 Fuel Cell Thermodynamics: Enthalpy 690
10.15.5 Entropy and the Theoretical Efficiency of Fuel Cells 694
10.15.6 Gibbs Free Energy and Fuel Cell Efficiency 697
10.15.7 Electrical Output of an Ideal Cell 698
10.15.8 Electrical Characteristics of Real Fuel Cells 699
10.15.9 Types of Fuel Cells 701
10.15.10 Producing Hydrogen 706
Problems 711
References 716
11 Microgrids 725
11.1 Introduction 725
11.2 Microgrids for Local Resilience 726
11.3 Microgrids for Off-Grid Applications 727
11.4 Off-Grid Solar PV with Battery Systems 728
11.4.1 Stand-Alone System Components 729
11.4.2 Self-Regulating Modules 731
11.4.3 Estimating the Load 733
11.4.4 Initial Array Sizing Assuming an MPP Tracker 737
11.4.5 Battery Sizing for Stand-Alone Systems 738
11.4.6 Sizing an Array with No MPP Tracker 742
11.4.7 A Simple Design Template 745
11.4.8 Stand-Alone PV System Costs 749
11.5 PV-Powered Water Pumping 751
11.5.1 The Electrical Side of the System 753
11.5.2 Hydraulic Pump Curves 754
11.5.3 Hydraulic System Curves 758
11.5.4 Putting It All Together to Predict Performance 761
11.6 Distributed Energy Resources 764
Problems 764
References 768
A Energy Economics Tutorial 771
A.1 Simple Payback Period 771
A.2 Initial (Simple) Rate of Return 772
A.3 The Time Value of Money and Net Present Value 772
A.4 Internal Rate of Return 775
A.5 Net Present Value with Fuel Escalation 777
A.6 IRR with Fuel Escalation 779
A.7 Annualizing the Investment 780
A.8 Levelized Cost of Electricity 781
A.9 Cash-Flow Analysis 785
Index 787
