(Parte 1 de 6)

Renewable Energy and the Environment

EnErgy and thE EnvironmEnt

SerieS editor abbas ghassemi New Mexico State University

PUbliShed titleS

Solar Energy: renewable Energy and the Environment robert Foster, Majid Ghassemi, Alma Cota

Wind Energy: renewable Energy and the Environment Vaughn Nelson

Renewable Energy and the Environment

Robert Foster

Majid Ghassemi Alma Cota

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Library of Congress Cataloging‑in‑Publication Data

Solar energy : renewable energy and the environment / Robert Foster … [et al.]. p. cm. -- (Energy and the environment)

Includes bibliographical references and index. ISBN 978-1-4200-7566-3 (hardcover : alk. paper) 1. Solar energy. 2. Renewable energy sources--Environmental aspects. I. Foster, Robert, 1962 Apr. 25- I. Title. II. Series.

Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com

Series Prefacexiii
The Series Editorxvii
Prefacexix
Acknowledgmentsxi
The Authorsxxv
The Contributorsxxvii
1ChapterIntroduction to Solar Energy ........................................................................................1
1.1 The Twenty-First Century’s Perfect Energy Storm1
1.2 Renewable Energy for Rural Development2
1.3 Renewable Energy Solutions3
1.4 Global Solar Resource4
Problems5
2ChapterSolar Resource ..............................................................................................................7
2.1 Introduction7
2.2 Sun–Earth Geometric Relationship7
2.2.1 Earth–Sun Distance8
2.2.2 Apparent Path of the Sun9
2.2.3 Earth and Celestial Coordinate Systems10
2.2.4 Position of the Sun with Respect to a Horizontal Surface12
2.2.5 Position of the Sun with Respect to a Tilted Surface2
2.3 Equation of Time26
2.4 Structure of the Sun29
2.5 Electromagnetic Radiation30
2.6 Solar Spectral Distribution3
2.7 Solar Constant34
2.8 Extraterrestrial Solar Radiation36
2.9 Terrestrial Solar Radiation37
2.10 Measurement of Terrestrial Solar Radiation40
2.1 Terrestrial Insolation on Tilted Collectors42
2.1.1 Instantaneous and Hourly Radiation46
2.1.2 Monthly Average Daily Insolation49
References52
Problems53
3Chapter Fundamentals of Engineering: Thermodynamics and Heat Transfer5
3.1 Introduction5
3.2 Conduction Heat Transfer5
Coordinate57
3.4 Thermal Resistance Circuits59

Contents 3.3 One-Dimensional Conduction Heat Transfer in a Rectangular 3.5 One-Dimensional Conduction Heat Transfer in a Cylindrical Coordinate .....60

3.6 Convection Heat Transfer63
3.7 Radiation Heat Transfer65
3.7.1 Surface Property6
3.7.2 Blackbody Radiation6
3.7.3 Real Body Radiation67
3.8 Introduction to Thermodynamics68
3.8.1 The First Law of Thermodynamics68
3.8.2 The Second Law of Thermodynamics69
3.8.3 The Third Law of Thermodynamics70
References70
Problems71
4Chapter Solar Thermal Systems and Applications73
4.1 Introduction73
4.2 Solar Collectors73
4.2.1 Flat-Plate Collectors74
4.2.1.1 Flat-Plate Collector Thermal Testing76
4.2.1.2 Collector Efficiency Curve78
4.2.2 Evacuated-Tube Solar Collectors78
4.2.3 Concentrating Collectors80
4.2.3.1 Optic Fundamentals for Solar Concentration84
4.2.3.2 Parabolic Concentrators87
4.2.4 Compound Parabolic Concentrators (CPCs)90
4.2.5 Fresnel Lens Concentrators94
4.2.6 Heliostats94
4.3 Tracking Systems96
4.4 Solar Thermal Systems97
4.4.1 Passive and Active Solar Thermal Systems9

vi Contents

Domestic Use9

4.4.1.1 Solar Thermal Application: Water Heating for

Industrial Use103
4.4.2 Case of Active Solar Drying: Sludge Drying103
4.4.2.1 Solar Thermal Application: Solar Distillation106
Desalination108
4.4.4 Case of Passive Solar Indirect Drying: Food Drying110
4.4.5 Case of an Active Solar Chemical Process: Water Detoxification110
References114
5ChapterPhotovoltaic Cells ..................................................................................................... 115

4.4.1.2 Solar Thermal Application: Water Heating for 4.4.3 Case of Passive Direct and Indirect Solar Distillation: Water Jeannette M. Moore

5.1 Introduction115
5.2 Crystal Structure115
5.3 Cell Physics117
5.4 Energy Bands118
5.5 More about Electrons and Their Energy119

5.6 Electrons and Holes ....................................................................................... 120

5.7 Direct and Indirect Band-Gap Materials120
5.8 Doping121
5.9 Transport122
5.10 Generation and Recombination122
5.1 The p–n Junction122
5.12 Solar Cell Equations124
5.13 Characterization125
5.14 Efficiency127
5.14.1 Temperature127
5.14.2 Light129
5.14.3 Type and Purity of Material129
5.14.4 Parasitic Resistances130
5.15 Current Research130
5.15.1 Concentrating Solar Cells130
5.15.2 Tandem Cells131
5.15.3 Thin Film Technologies131
5.15.4 Quantum Dots131
5.16 Cell Applications132
5.16.1 Utility Power Generation132
5.16.2 Space Systems132
5.16.3 Solar-Powered Products133
References133
Problems133
6ChapterPhotovoltaic Conversion Systems ............................................................................. 135
6.1 Solar Benefits135
6.1.1 Energy Alternatives136
6.2 Basic Module Electrical Concepts137
6.2.1 PV Electrical Characteristics137
6.2.2 Common PV Terminology138
6.2.3 I-V Curves138
6.3 PV Arrays141
6.3.1 Increasing Voltage141
6.3.2 Increasing Current142
6.4 PV Array Tilt143
6.5 PV Balance of Systems144
6.5.1 Energy Storage145
6.5.2 Charge Controllers145
6.5.3 Inverters and Converters145
6.6 PV System Utility148
6.6.1 Grounding and Bonding DC and AC Circuits148
6.6.2 Net Metering150
6.7 PV System Safety150
6.8 PV System Testing Rules150
References151
Problems151
7Chapter Photovoltaic System Sizing and Design153

Contents vii 7.1 Introduction ................................................................................................... 153

7.2 Solar Resource Sizing Considerations153
7.3 Solar Trajectory154
7.4 Solar Energy System Sizing Considerations155
7.5 Solar Energy System Sizing156
7.5.1 Example of Simple PV DC System Sizing156
7.5.2 Sizing Inverters157
7.5.2.1 Technical Specifications158
7.5.2.2 Load Estimation158
7.5.2.3 Battery Storage Requirement158
7.5.2.4 Array Estimation159
7.5.2.5 System Summary159
7.6 Solar Water Pumping System Sizing159
7.6.1 General Method of Sizing a Solar Pump160
7.7 Generic Water Pump Sizing Methodology161
7.8 Electrical Codes for PV System Design164
7.9 Stand-Alone PV Lighting Design Example169
References172
Problems172
8ChapterPhotovoltaic (PV) Applications ................................................................................ 173
8.1 Introduction173
8.2 Grid-Tied PV173
8.3 Japanese PV Development and Applications175
8.3.1 Japanese Government’s Approach178
8.3.2 Japanese PV Utilities179
8.3.3 Japanese Marketing180
8.3.4 Japanese PV Electrical Code181
8.3.5 Japanese PV Design182
8.3.6 Japanese PV System Guarantees184
8.3.7 Japanese PV Development184
8.3.8 Japanese PV Module Certification185
8.4 Future Japanese Trends187
8.5 Stand-Alone PV Applications188
8.5.1 PV Solar Home Lighting Systems188
8.5.2 PV Battery Charging Stations192

viii Contents 8.5.3 PVLS Human Motivation: the Final Driver of System Success

Corsair, The Johns Hopkins University]195

[Guest Authors Debora Ley, University of Oxford and H. J. 8.5.4 PV in Xenimajuyu: the Xocoy Family

Corsair, The Johns Hopkins University]196
8.6 PV for Schools197
8.7 PV for Protected Areas199
8.7.1 PV Ice-Making and Refrigeration202
8.7.2 PV Ice-Making203
8.8 PV Water-Pumping204
8.8.1 Hydraulic Workloads205
8.8.2 Other Considerations206

[Guest Authors Debora Ley, University of Oxford and H. J. 8.8.3 Pressure ............................................................................................207

8.8.4 Static Head207
8.8.5 Pumping Requirements208
8.8.6 Dynamic Systems208
8.8.7 Water Demand210
8.8.7.1 Water Resources211
8.8.8 Storage of Water versus Storage of Energy in Batteries212
8.8.9 Pumping Mechanisms Used for Solar Pumps213
8.8.9.1 Centrifugal Pumps213
8.8.9.2 Positive Displacement Pumps213
8.8.9.3 Surface Pumps versus Submersible Pumps214
8.8.10 Types of Motors Used with Solar Pumps216
8.8.1 Solar Pump Controllers217
8.8.1.1 Additional Features of Pump Controllers217
8.8.12 Pump Selection218
8.8.13 Installation, Operation, and Maintenance218
8.8.14 System Installation219
8.8.14.1 Civil Works220
8.8.14.2 Piping221
8.8.14.3 Surface-Pump Installation221

Contents ix

Noise2
8.8.14.5 Installation of Submersible Pumps2
8.9 Grounding and Lightning Protection for Solar Water Pumps2
Electrical Enclosures223
8.9.2 Ground223
8.9.3 Float Switch Cable223
8.9.4 Additional Lightning Protection224
8.10 Solar Tracking for Solar Water Pumps224
8.10.1 Passive Trackers224
8.10.2 Active Trackers versus Passive Trackers225
8.1 Operation and Maintenance of the Systems225
8.12 The PV Array226
8.12.1 Pumps and Motors227
8.12.2 Water Supply Systems227
8.13 PV Water-Pumping Results227
References228
9ChapterEconomics ................................................................................................................ 231

8.8.14.4 Surface Water Pumps: Preventing Cavitation and 8.9.1 Bond (Interconnect) All Metal Structural Components and Vaughn Nelson

9.1 Solar Energy Is Free, but What Does It Cost?231
9.2 Economic Feasibility232
9.2.1 PV Costs232
9.3 Economic Factors233
9.4 Economic Analysis233
9.4.1 Simple Payback234
9.4.2 Cost of Energy235
9.5 Life Cycle Cost236

9.6 Present Value and Levelized Costs................................................................238

9.6.1 Steps to Determine the LCC239
9.7 Annualized Cost of Energy240
9.8 Externalities240
9.8.1 Externality Evaluation Methods241
9.8.2 Societal Perspectives on Solar Energy Utilization241
9.9 Solar Irrigation Case Study242
9.9.1 Estimating System Costs242
9.9.2 Table of Approximate Costs242
9.9.3 Comparison of Pumping Alternatives243
9.10 Water Pumping Example245
9.1 Summary246
References248
Problems248
1Chapter 0 Institutional Issues249
10.1 Introduction249
10.2 Sustainability249
10.3 Institutional Considerations250
10.3.1 Policy Issues250
10.3.2 Capacity Building250
10.3.3 Education and Training251
10.3.4 Technical Assistance251
10.3.5 Local Infrastructure Development251
10.3.6 Involving the Community: Sustainability and Inclusion252
10.4 Stakeholders252
10.4.1 Panels versus Fuel or Electric Bills252
10.4.2 Community Reduction of Theft Risks253
10.4.3 PV and the “Virtuous Circle”254
10.5 Program Implementation254
10.5.1 Conduct Strategic Planning254
10.5.2 Pilot Project Implementation255
10.5.3 Create Sustainable Markets255
10.5.4 Grassroots Development Approach255
10.5.5 Install Appropriate Hardware255
10.5.6 Monitoring256
10.6 Institutional Models for Solar Energy Dissemination256
10.6.1 Cash Sales257
10.6.2 Consumer Financing258
10.6.2.1 Revolving Credit Fund259
10.6.2.2 Local Bank Credit259
10.6.3 Leasing259
10.6.3.1 Dealer Credit259
10.6.4 Subsidies260
10.7 Management and Ownership260
10.7.1 Authorization Arrangement260
10.7.2 Contracts260
10.7.3 Leases260
10.7.4 Ownership Transfer (Flip Model)261

x Contents 10.7.5 Associations and Cooperatives ......................................................... 261

10.8 Tariffs and Payment261
10.8.1 Free261
10.8.2 Nominal (Subsidized)261
10.8.3 Fee for Service262
10.8.4 Payment262
10.9 Other Critical Issues262
10.10 Summary262
Problems263
1Chapter 1 Energy Storage265
1.1 Introduction265
1.2 Batteries in PV Systems265
1.2.1 Lead-Antimony Batteries266
1.2.2 Lead-Calcium Batteries267
1.2.3 Captive Electrolyte Batteries267
1.2.4 Nickel-Cadmium Batteries268
1.3 Lead-Acid Battery Construction268
1.3.1 Plate Grids268
1.3.1.1 Positive and Negative Plates268
1.3.1.2 Separators269
1.3.1.3 Elements269
1.3.1.4 Cell Connectors270
1.3.1.5 Containers270
1.3.1.6 Vent Plugs270
1.4 Lead-Acid Battery Operation270
1.4.1 Discharge Cycle271
1.4.2 Charge Cycle272
1.4.3 Electrolyte and Specific Gravity272
1.4.4 Water273
1.4.5 Battery Roundtrip Efficiency273
1.5 Lead-Acid Battery Characteristics273
1.5.1 Ampere-Hour Storage Capacity273
1.5.2 Battery Cycle Life274
1.5.3 Battery Connections275
1.6 Battery Problem Areas276
1.6.1 Overcharging276
1.6.2 Undercharging276
1.6.3 Short Circuits276
1.6.4 Sulfation277
1.6.5 Water Loss277
1.6.6 Self-Discharge278
1.7 Battery Maintenance278
1.7.1 Hydrometer Description and Use280
1.7.2 Temperature Correction280
1.7.3 Tropical Climates280
1.8 Battery Safety Precautions281
1.8.1 Battery Acid283
1.8.2 Hydrogen Gas283

Contents xi 1.8.3 Battery Enclosures............................................................................284

1.9 Determination of Battery Failure284
1.9.1 Battery Applications and Installation284
1.9.2 Battery Service History284
1.9.3 Visual Inspection286
1.9.4 Battery Age286
1.9.5 Overcharging and Undercharging286
1.9.6 Internal Examination287
1.9.7 Container287
1.9.8 Electrolyte287
1.10 Battery Selection Criteria287
1.10.1 Battery Procurement Considerations288
1.10.1.1 Additional Battery Manufacturer Specifications288
1.10.2 Additional Battery System Considerations289
1.10.2.1 Small-System Considerations289
1.10.2.2 Large-System Considerations289
1.1 Charge Controller Terminology289
1.12 Charge Controller Algorithms290
1.12.1 Shunt Controller290
1.12.2 Series Controller291
1.13 Charge Controller Selection Criteria292
1.13.1 Charge Controller Procurement Specifications292

xii Contents

Specifications292
References293
Problems293
Solar Energy Glossary295
Batteries295
Electricity298
Photovoltaics300
Solar Energy Concepts302
Solar Water-Pumping303
Appendix A: World Insolation Data307
Appendix B: Friction Loss Factors327
Appendix C: Present Value Factors331
Appendix D: Table of Approximate PV Pumping-System Costs335

1.13.1.2 Additional Charge Controller Manufacturer Index .............................................................................................................................................. 337 xiii

Series Preface

By 2050 the demand for energy could double or even triple as the global population grows and developing countries expand their economies. All life on Earth depends on energy and the cycling of carbon. Energy is essential for economic and social development and also poses an environmental challenge. We must explore all aspects of energy production and consumption, including energy efficiency, clean energy, the global carbon cycle, carbon sources, and sinks and biomass, as well as their relationship to climate and natural resource issues. Knowledge of energy has allowed humans to flourish in numbers unimaginable to our ancestors.

The world’s dependence on fossil fuels began approximately 200 years ago. Are we running out of oil? No, but we are certainly running out of the affordable oil that has powered the world economy since the 1950s. We know how to recover fossil fuels and harvest their energy for operating power plants, planes, trains, and automobiles; this leads to modifying the carbon cycle and additional greenhouse gas emissions. The result has been the debate on availability of fossil energy resources; peak oil era and timing for anticipated end of the fossil fuel era; price and environmental impact versus various renewable resources and use; carbon footprint; and emissions and control, including cap and trade and emergence of “green power.”

Our current consumption has largely relied on oil for mobile applications and coal, natural gas, and nuclear or water power for stationary applications. In order to address the energy issues in a comprehensive manner, it is vital to consider the complexity of energy. Any energy resource, including oil, coal, wind, and biomass, is an element of a complex supply chain and must be considered in its entirety as a system from production through consumption. All of the elements of the system are interrelated and interdependent. Oil, for example, requires consideration for interlinking of all of the elements, including exploration, drilling, production, water, transportation, refining, refinery products and byproducts, waste, environmental impact, distribution, consumption/application, and, finally, emissions.

Inefficiencies in any part of the system have an impact on the overall system, and disruption in one of these elements causes major interruption in consumption. As we have experienced in the past, interrupted exploration will result in disruption in production, restricted refining and distribution, and consumption shortages. Therefore, any proposed energy solution requires careful evaluation and, as such, may be one of the key barriers to implementing the proposed use of hydrogen as a mobile fuel.

Even though an admirable level of effort has gone into improving the efficiency of fuel sources for delivery of energy, we are faced with severe challenges on many fronts. These include population growth, emerging economies, new and expanded usage, and limited natural resources. All energy solutions include some level of risk, including technology snafus, changes in market demand, and economic drivers. This is particularly true when proposing an energy solution involving implementation of untested alternative energy technologies.

There are concerns that emissions from fossil fuels will lead to changing climate with possibly disastrous consequences. Over the past five decades, the world’s collective greenhouse gas emissions have increased significantly—even as increasing efficiency has resulted in extending energy benefits to more of the population. Many propose that we improve the efficiency of energy use and conserve resources to lessen greenhouse gas emissions and avoid a climate catastrophe. Using fossil fuels more efficiently has not reduced overall greenhouse gas emissions for various reasons, and it is unlikely that such initiatives will have a perceptible effect on atmospheric greenhouse gas content. Although the correlation between energy use and greenhouse gas emissions is debatable, there are effective means to produce energy, even from fossil fuels, while controlling emissions. Emerging technologies and engineered alternatives will also manage the makeup of the atmosphere, but will require significant understanding and careful use of energy.

xiv Series Preface

We need to step back and reconsider our role in and knowledge of energy use. The traditional approach of micromanagement of greenhouse gas emissions is not feasible or functional over a long period of time. More assertive methods to influence the carbon cycle are needed and will be emerging in the coming years. Modifications to the cycle mean that we must look at all options in managing atmospheric greenhouse gases, including various ways to produce, consume, and deal with energy. We need to be willing to face reality and search in earnest for alternative energy solutions. Some technologies appear to be able to assist; however, all may not be viable. The proposed solutions must not be in terms of a “quick approach,” but rather as a more comprehensive, long-term (10, 25, and 50+ years) approach based on science and utilizing aggressive research and development. The proposed solutions must be capable of being retrofitted into our existing energy chain. In the meantime, we must continually seek to increase the efficiency of converting energy into heat and power.

One of the best ways to define sustainable development is through long-term, affordable availability of resources, including energy. There are many potential constraints to sustainable development. Foremost of these is the competition for water use in energy production, manufacturing, and farming versus a shortage of fresh water for consumption and development. Sustainable development is also dependent on the Earth’s limited amount of soil; in the not too distant future, we will have to restore and build soil as a part of sustainable development. Hence, possible solutions must be comprehensive and based on integrating our energy use with nature’s management of carbon, water, and life on Earth as represented by the carbon and hydrogeological cycles.

Obviously, the challenges presented by the need to control atmospheric greenhouse gases are enormous and require “out of the box” thinking, innovative approaches, imagination, and bold engineering initiatives in order to achieve sustainable development. We will need to exploit energy even more ingeniously and integrate its use with control of atmospheric greenhouse gases. The continued development and application of energy is essential to the development of human society in a sustainable manner through the coming centuries.

All alternative energy technologies are not equal; they have various risks and drawbacks. When evaluating our energy options, we must consider all aspects, including performance against known criteria, basic economics and benefits, efficiency, processing and utilization requirements, infrastructure requirements, subsidies and credits, and waste and the ecosystem, as well as unintended consequences such as impacts on natural resources and the environment. Additionally, we must include the overall changes and the emerging energy picture based on current and future efforts to modify fossil fuels and evaluate the energy return for the investment of funds and other natural resources such as water.

A significant driver in creating this book series focused on alternative energy and the environment and was initiated as a consequence of lecturing around the country and in the classroom on the subject of energy, environment, and natural resources such as water. Water is a precious commodity in the West in general and the Southwest in particular and has a significant impact on energy production, including alternative sources, due to the nexus between energy and water and the major correlation with the environment and sustainability-related issues. The correlation among these elements, how they relate to each other, and the impact of one on the other are understood; however, integration and utilization of alternative energy resources into the energy matrix has not been significantly debated.

Also, as renewable technology implementation grows by various states nationally and internationally, the need for informed and trained human resources continues to be a significant driver in future employment. This has resulted in universities, community colleges, and trade schools offering minors, certificate programs, and, in some cases, majors in renewable energy and sustainability. As the field grows, the demand increases for trained operators, engineers, designers, and architects able to incorporate these technologies into their daily activity. Additionally, we receive daily deluges of flyers, e-mails, and texts on various short courses available for parties interested in solar, wind, geothermal, biomass, and other types of energy. These are under the umbrella of retooling

Series Preface xv an individual’s career and providing the trained resources needed to interact with financial, governmental, and industrial organizations.

In all my interactions in this field throughout the years, I have conducted significant searches for integrated textbooks that explain alternative energy resources in a suitable manner that would complement a syllabus for a potential course to be taught at the university and provide good reference material for parties getting involved in this field. I have been able to locate a number of books on the subject matter related to energy; energy systems; and resources such as fossil nuclear, renewable energy, and energy conversion, as well as specific books on the subjects of natural resource availability, use, and impact as related to energy and environment. However, books that are correlated and present the various subjects in detail are few and far between.

We have therefore started a series in which each text addresses specific technology fields in the renewable energy arena. As a part of this series, there are textbooks on wind, solar, geothermal, biomass, hydro, and other energy forms yet to be developed. Our texts are intended for upper level undergraduate and graduate students and informed readers who have a solid fundamental understanding of science and mathematics. Individuals and organizations that are involved with design development of the renewable energy field entities and interested in having reference material available to their scientists and engineers, consulting organizations, and reference libraries will also be interested in these texts. Each book presents fundamentals as well as a series of numerical and conceptual problems designed to stimulate creative thinking and problem solving.

(Parte 1 de 6)

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