Biofuels, Solar and Wind as Renewable Energy Systems (eBook)

David Pimentel is a professor of ecology and agricultural sciences at Cornell University, Ithaca, NY 14853-0901. His Ph.D. is from Cornell University. His research spans the fields of energy, ecological and economic aspects of pest control, biological control, biotechnology, sustainable agriculture, land and water conservation, and environmental policy. Pimentel has published more than 600 scientific papers and 25 books and has served on many national and government committees including the National Academy of Sciences; President’s Science Advisory Council; U.S Department of Agriculture; U.S. Department of Energy; U.S. Department of Health, Education and Welfare; Office of Technology Assessment of the U.S. Congress; and the U.S. State Department.

Preface 5
Acknowledgements 7
Contents 8
About our Authors 10
Contributors 17
Renewable and Solar Energy Technologies: Energy and Environmental Issues 20
1.1 Introduction 20
1.2 Hydroelectric Power 21
1.3 Biomass Energy 23
1.4 Wind Power 24
1.5 Solar Thermal Conversion Systems 25
1.6 Photovoltaic Systems 26
1.7 Geothermal Systems 27
1.8 Biogas 28
1.9 Ethanol and Energy Inputs 28
1.10 Grasslands and Celulosic Ethanol 30
1.11 Methanol and Vegetable Oils 30
1.12 Transition to Renewable Energy 31
1.13 Conclusion 32
References 33
Can the Earth Deliver the Biomass-for-Fuel we Demand? 37
2.1 Introduction 37
2.2 Background 40
2.3 Plan of Attack 45
2.4 Efficiency of Cellulosic Ethanol Refineries 46
2.5 Where will the Agrofuel Biomass Come from? 51
2.6 Conclusions 62
References 62
Appendix 1: Ecosystem Definition and Properties 64
Appendix 2: Mass Balance of Carbon in an Ecosystem 66
Appendix 3: Environmental Controls on Net 70
Primary Productivity 70
Glossary 72
A Review of the Economic Rewards and Risks of Ethanol Production 74
3.1 Introduction 74
3.2 Measuring and Mismeasuring Biofuels Economic Impacts 76
3.3 Ethanol Production Economic Opportunities and Offsets 81
3.4 Bioenergy Promotion and the Overall Sustainability 89
of Rural Economies 89
References 94
Subsidies to Ethanol in the United States 96
Acronyms & abbreviations
4.1 Introduction 97
4.2 Evolution of Federal Policies Supporting Liquid Biofuels 99
4.3 Current Policies Supporting Ethanol 101
4.4 Aggregate Support to Ethanol 113
4.5 Pending Legislation 119
4.6 Conclusions 120
References 122
Peak Oil, EROI, Investments and the Economy in an Uncertain Future 126
5.1 Introduction 127
5.2 The Age of Petroleum 127
5.3 How much Oil will we be able to Extract? 129
5.4 Decreasing Energy Return on Investment 134
5.5 The Balloon Graph 136
5.6 Economic Impacts of Peak Oil and Decreasing EROI 138
5.7 The “Cheese Slicer” Model 139
5.8 Results of Simulation 144
5.9 Discussion 144
5.10 Conclusion 147
References 147
Wind Power: Benefits and Limitations 150
6.1 Introduction 150
6.2 The Power Density of Electricity from Wind Turbines 152
6.3 Producing the Output of a Power Station from Wind Power 153
6.4 The Problem of Assessing Energy with Respect to Wind Turbines 154
6.5 The Implications of the Uncontrollable Nature of the Output from Wind Turbines 155
6.6 The Problems of Operating in Harness with Wind Turbines 156
6.7 Alternatives toWind Power 157
6.8 The Problems of Storage 158
6.9 The Problem of ‘Liquid’ Fuel in a Fossil-Fuel-Free Society 163
6.10 Learning from Experience (Denmark) 164
6.11 Making Realistic Assessments of the Cost ofWind Power 165
6.12 Conclusion 165
Notes 166
References 168
Renewable Diesel 169
7.1 Introduction 169
7.2 The Diesel Engine 170
7.3 Ecological Limits 170
7.4 Straight Vegetable Oil 172
7.5 Biodiesel 172
7.6 Green Diesel 175
7.7 Feed Stocks 177
7.8 Conclusions 183
7.9 Conversion Factors and Calculations 183
References 185
Complex Systems Thinking and Renewable Energy Systems 188
8.1 Theoretical Issues: The Problems Faced by Energy Analysis 189
8.2 Basic Concepts of Bioeconomics 198
8.3 Using the MuSIASEM Approach to Check the Viability of Alternative Energy Sources: An Application to Biofuels 209
8.4 Conclusion 220
References 224
Sugarcane and Ethanol Production and Carbon Dioxide Balances 229
9.1 Introduction 229
9.2 The “Green” Promise 230
9.3 CO2 Emissions of Sugarcane Ethanol 230
9.4 Gasoline Versus Ethanol 233
9.5 Bagasse as a Source of Energy 233
9.6 Pre-Harvest Burning of Sugarcane and Mechanical Harvest 235
9.7 Distillery Wastes 236
9.8 Possible Additional Sources of Methane 237
9.9 CO2 Mitigation 237
9.10 Variations of CO2 Emissions Calculations 238
9.11 A Trend in the Near Future 239
9.12 Environmental Impacts Versus CO2 Emissions 240
9.13 Conclusions 241
References 242
Biomass Fuel Cycle Boundaries and Parameters: Current Practice and Proposed Methodology 245
Acronyms & abbreviations
10.1 Introduction 246
10.2 BFC Analysis Methodology: A Modular Model Approach 246
10.3 BFC Fuel and Net Energy Balance Definitions 254
10.4 BFC Models 256
10.5 Other Considerations 269
References 270
Our Food and Fuel Future 272
11.1 Introduction 273
11.2 Price and Availability of Traditional Fuels 273
11.3 Alternative Sources of Energy 280
11.4 GreenhouseWarming and its Connections 294
11.5 Political and Social Conditions, Especially 298
in the United States 298
11.6 Conclusions 302
References 305
A Framework for Energy Alternatives: Net Energy, Liebig’s Law and Multi-criteria Analysis 308
12.1 Introduction 308
12.2 Net Energy Analysis 309
12.3 An Introduction to EROI – Energy Return on Investment 309
12.4 Humans and Energy Gain 310
12.5 Current Energy Gain 311
12.6 An Energy Theory of Value 312
12.7 Why is Net Energy Important? 312
12.8 Net Energy and Energy Quality 313
12.9 Energy Return on Investment – Towards a Consistent Framework 315
12.10 A Framework for Analyzing EROI 318
12.11 Non-Energy Inputs 319
12.12 Non-Energy Outputs 321
12.13 Non-Market Impacts 321
12.14 A Summary of Methodologies 322
12.15 A Unifying EROI Framework 323
12.16 Liebig’s Law, Multi-Criteria Analysis, and Energy from Biofuels 325
12.17 Conclusion 328
References 329
Bio-Ethanol Production in Brazil 333
13.1 Historical Introduction 334
13.2 The Sugarcane Crop in Brazil 337
13.3 Environmental Impact 342
13.4 Labour Conditions 362
13.5 Conclusions 363
References 365
Ethanol Production: Energy and Economic Issues Related to U.S. and Brazilian Sugarcane 369
14.1 Introduction 369
14.2 Energy Inputs in Sugarcane Production 370
14.3 Energy Inputs in Fermentation/Distillation 372
14.4 Energy Yield 374
14.5 Economic Costs 374
14.6 Land Use in the U.S. 375
14.7 Ethanol Production and Use in Brazil 376
14.8 Environmental Impacts 376
14.9 Air Pollution 377
14.10 Food Security 378
14.11 Food versus the Fuel Issue 378
14.12 Summary 379
References 380
Ethanol Production Using Corn, Switchgrass and Wood Biodiesel Production Using Soybean
15.1 Introduction 384
15.2 Energy Inputs in Corn Production 385
15.3 Cellulosic Ethanol 391
15.4 Switchgrass Production of Ethanol 393
15.5 Wood Cellulose Conversion into Ethanol 394
15.6 Biodiesel Production 397
15.7 Soybean Conversion into Biodiesel 397
15.8 Canola Conversion into Biodiesel 399
15.9 Conclusion 400
References 402
Developing Energy Crops for Thermal Applications: Optimizing Fuel Quality, Energy Security and GHG Mitigation 406
Acronyms & abbreviations
16.1 Introduction 407
16.2 Energy Crop Production for Energy Security and GHG Mitigation 408
16.3 Optimization of Energy Grasses for Combustion Applications 422
16.4 Outlook 429
References 430
Organic and Sustainable Agriculture and Energy Conservation 435
17.1 Organic Agriculture: An Overview 436
17.2 Organic Agriculture: An Energy-Saving Alternative? 448
17.3 CO2 Emissions and Organic Management 453
17.4 Agricultural “Waste ” for Cellulosic Ethanol Production or Back to the Field? 458
17.5 Organically Produced Biofuels? 461
17.6 Conclusion 464
References 466
Biofuel Production in Italy and Europe: Benefits and Costs, in the Light of the Present European 475
18.1 Introduction 476
18.2 To What extent Would a Large Scale Biofuel Production Really Replace Fossil Fuels? 477
18.3 Physical Constraints Other than Energy 487
18.4 The Large-Scale Picture. An Overview of Substitution Scenarios 490
18.5 Discussion 493
18.6 Conclusions 497
References 499
The Power Density of Ethanol from Brazilian Sugarcane 502
19.1 Introduction 502
19.2 Errors and the Potential for More Relating to Sugarcane 505
19.3 Soil Erosion Problems 506
References 507
A Brief Discussion on Algae for Oil Production: Energy Issues 508
References 509
Index 510

Chapter 3

A Review of the Economic Rewards and Risks of Ethanol Production (p. 57-58)

David Swenson

Abstract Ethanol production doubled in a very short period of time in the U.S. due to a combination of natural disasters, political tensions, and much more demand globally from petroleum. Responses to this expansion will span many sectors of society and the economy. As the Midwest gears up to rapidly add new ethanol manufacturing plants, the existing regional economy must accommodate the changes. There are issues for decision makers regarding existing agricultural activities, transportation and storage, regional economic impacts, the likelihood of growth in particular areas and decline in others, and the longer term economic, social, and environmental sustainability. Many of these issues will have to be considered and dealt with in a simultaneous fashion in a relatively short period of time.

This chapter investigates sets of structural, industrial, and regional consequences associated with ethanol plant development in the Midwest, primarily, and in the nation, secondarily. The first section untangles the rhetoric of local and regional economic impact claims about biofuels. The second section describes the economic gains and offsets that may accrue to farmers, livestock feeding, and other agri-businesses as production of ethanol and byproducts increase. The last section discusses the near and longer term growth prospects for rural areas in the Midwest and the nation as they relate to biofuels production.

Keywords Ethanol · economic impact · biofuels · farmer ownership · scale economies · storage · grain supply · rural development · cellulosic ethanol

3.1 Introduction

The economic, social, political, and environmental impacts of modern ethanol production in the U.S. are highly regionalized. Current ethanol production and most new ethanol plant development in the United States are concentrated in the Corn Belt states of Iowa, Illinois, Indiana, Minnesota, and Nebraska. Those states alone produced nearly 62 percent of the nation’s corn in 2006. Not surprisingly, those same states account for about two-thirds of actual or planned ethanol production capacity.

Ethanol production and plant development took on an added urgency in the fall of 2005 after hurricanes Katrina and Rita crippled domestic oil production capacity in the Gulf of Mexico. Those events, coupled with heightened uncertainty about both near-term and long-term oil supplies in light of other international issues, fueled massive amounts of rhetorical, political, and financial resources in support of biofuels production and energy independence.

The growth in U.S. ethanol production has been dramatic: In 2005, 1.6 billion bushels of corn were converted to ethanol, about 12.1 percent of the total corn supply. By the end of 2007 it is estimated that 3.2 billion bushels will be used for that purpose, about a quarter of the nation’s corn supply, and an increase of just over 100 percent in only two years (USDA 2007). That much corn will make enough ethanol to account for 3.9 percent of the nation’s total demand for motor gasoline that year (EIA 2007).