Biofuels, Solar and Wind as Renewable Energy Systems: Benefits and Risks pptx

Biofuels, Solar and Wind as Renewable
Energy Systems
David Pimentel
Editor
Biofuels, Solar and Wind
as Renewable Energy
Systems
Benefits and Risks
123
Editor
Dr. David Pimentel
Cornell University
College of Agriculture and Life Sciences
5126 Comstock Hall
Ithaca, NY 15850
USA

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Preface
The petroleum age began about 150 years ago. Easily available energy has sup-
ported major advances in agriculture, industry, transportation, and indeed many
diverse activities valued by humans. Now world petroleum and natural gas sup-
plies have peaked and their supplies will slowly decline over the next 40–50 years
until depleted. Although small amounts of petroleum and natural gas will remain
underground, it will be energetically and economically impossible to extract. In the
United States, coal supplies could be available for as long as 40–50 years, depending
on how rapidly coal is utilized as a replacement for petroleum and natural gas.
Having been comfortable with the security provided by fossil energy, especially
petroleum and natural gas, we appear to be slow to recognize the energy crisis in the
U.S. and world. Serious energy conservation and research on viable renewable en-
ergy technologies are needed. Several renewable energy technologies already exist,
but sound research is needed to improve their effectiveness and economics. Most of
the renewable energy technologies are influenced by geographic location and face
problems of intermittent energy supply and storage. Most renewable technologies
require extensive land; a few researchers have even suggested that one-half of all
land biomass could be harvested in order to supply the U.S. with 30% of its liquid
fuel!
Some optimistic investigations of renewable energy have failed to recognize that

only 0.1% of the solar energy is captured annually in the U.S. by all the green plants,
including agriculture, forestry, and grasslands. Photovoltaics can collect about 200
times more solar energy per year than green plants. The green plants took more than
700 million years to collect and then be stored as the concentrated energy found in
petroleum, natural gas, and coal supplies.
This book examines various renewable energy technologies and reports on their
potential to supply the United States and other nations with needed energy. Some
chapters examine several renewable energy technologies and their potential to re-
place fossil fuel, while others focus on one specific technology and its potential, as
well as its limitations. In this volume, the aim of the contributors is to share their
analyses as a basis for more research in renewable energy technologies. Basic to all
the renewable energy technologies is that they attempt to minimize damage to the
environment that supports all life.
v
vi Preface
Several of the chapters reflect the current lack of agreement in the field, as pres-
sure mounts to explore and develop potential energy alternatives. The reader will
notice considerable variability in the energy inputs and potential energy outputs
in some of the studies. This is evidence of the complexity of assessing the large
number of energy inputs that go into production of a biofuel crop and the extraction
of its useful energy. As research continues, we will discover if current analyses
of renewable energy technologies have adequately estimated energy requirements,
outputs and environmental consequences. Hopefully, this research will help guide
energy policy makers toward the most viable choices and away from energy costly
missteps, as we collectively encounter energy descent.
The authors of each of these chapters have done a superb job in presenting the
most up to date perspective of various renewable energy technologies in a highly
readable fashion.
NY, USA D. Pimentel
Acknowledgements

I wish to express my sincere gratitude to the Cornell Association of Professors
Emeriti for the partial support of our research through the Albert Podell Grant
Program. In addition, I wish to thank Anne Wilson for her valuable assistance in
the preparation of our book.
vii
Contents
1 Renewable and Solar Energy Technologies: Energy and
Environmental Issues 1
David Pimentel
2 Can the Earth Deliver the Biomass-for-Fuel we Demand? 19
Tad W. Patzek
3 A Review of the Economic Rewards and Risks of Ethanol Production 57
David Swenson
4 Subsidies to Ethanol in the United States 79
Doug Koplow and Ronald Steenblik
5 Peak Oil, EROI, Investments and the Economy in an Uncertain
Future 109
Charles A. S. Hall, Robert Powers and William Schoenberg
6 Wind Power: Benefits and Limitations 133
Andrew R.B. Ferguson
7 Renewable Diesel 153
Robert Rapier
8 Complex Systems Thinking and Renewable Energy Systems 173
Mario Giampietro and Kozo Mayumi
9 Sugarcane and Ethanol Production and Carbon Dioxide Balances 215
Marcelo Dias De Oliveira
10 Biomass Fuel Cycle Boundaries and Parameters: Current Practice
and Proposed Methodology 231
Tom Gangwer
ix

x Contents
11 Our Food and Fuel Future 259
Edwin Kessler
12 A Framework for Energy Alternatives: Net Energy, Liebig’s Law
and Multi-criteria Analysis 295
Nathan John Hagens and Kenneth Mulder
13 Bio-Ethanol Production in Brazil 321
Robert M. Boddey, Luis Henrique de B. Soares, Bruno J.R. Alves
and Segundo Urquiaga
14 Ethanol Production: Energy and Economic Issues Related to U.S.
and Brazilian Sugarcane 357
David Pimentel and Tad W. Patzek
15 Ethanol Production Using Corn, Switchgrass and Wood; Biodiesel
Production Using Soybean 373
David Pimentel and Tad Patzek
16 Developing Energy Crops for Thermal Applications: Optimizing
Fuel Quality, Energy Security and GHG Mitigation 395
Roger Samson, Claudia Ho Lem, Stephanie Bailey Stamler
and Jeroen Dooper
17 Organic and Sustainable Agriculture and Energy Conservation 425
Tiziano Gomiero and Maurizio G. Paoletti
18 Biofuel Production in Italy and Europe: Benefits and Costs, in the
Light of the Present European Union Biofuel Policy 465
Sergio Ulgiati, Daniela Russi and Marco Raugei
19 The Power Density of Ethanol from Brazilian Sugarcane 493
Andrew R.B. Ferguson
20 A Brief Discussion on Algae for Oil Production: Energy Issues 499
David Pimentel
Index 501
About our Authors

Bruno J. R. Alves graduated in Agronomy from UFRRJ (Federal University of Rio
de Janeiro) in 1987. He concluded the Master’s Degree (1992) and PhD (1996) in
Agronomy at the same University, specializing in techniques for the study of the
dynamics of N in the soil and for the quantification of biological N2 fixation in
legume and non-legume species. He is a researcher at the Brazilian Corporation
of Agricultural Research (Embrapa) and a teacher-advisor in the post-graduation
program in Agronomy at UFRRJ. His research covers the quantification of soil C
sequestration, greenhouse gas emissions, and energy balance for biomass produc-
tion.
Robert Boddey graduated in 1975 from Leeds University, UK, with a BSc in Agri-
cultural Chemistry. He earned a PhD at the University of the West Indies (Trinidad)
in 1980, with a thesis on biological nitrogen fixation (BNF) associated with wetland
rice. He then moved to the Soil Microbiology Centre of the Brazilian Corporation
for Agricultural Research (Embrapa Agrobiologia) in Serop
´
edica, Rio de Janeiro.
There he developed various techniques, including those using the stable isotope
15N, to quantify inputs of BNF to grasses and cereals. His team also works on the
impact of BNF on N dynamics in various agroecosystems. Boddey has published
almost 100 papers in international journals, and over 60 chapters in books and con-
ference proceedings.
Marcelo E. Dias de Oliveira graduated in 1997 as an Agronomic Engineer at Uni-
versity of S
˜
ao Paulo-Brazil, working as an undergrad student with GIS and Remote
Sensing. In 2001 he started his Master’s Degree at Washington State University –
Richland - USA, concluding his work in 2004. During this time he did research on
hazardous materials at the Hanford site, and developed his thesis on energy balance,
carbon dioxide emissions and environmental impacts of ethanol production. Cur-
rently he works as consultant for an environmental company in Brazil and is about

to start his PhD studies.
Jeroen Dooper holds a Bachelor degree in Ecological Material Technology and is
currently completing a Master’s degree in Sustainable Development, Energy and
xi
xii About our Authors
Resources at Utrecht University in the Netherlands. His research is focused on en-
ergy conversion technologies, energy policies, greenhouse gas mitigation and life
cycle assessments. In 2007, he began collaboration with REAP-Canada to pursue
research on various bioenergy conversion technologies and their efficiencies. His
previous work experience includes environmental education at Econsultancy, and
environmental consulting, environmental product development, and optimizing pro-
cessing efficiency with the Avans University of Professional Education.
Andrew Ferguson, after National Service flying training in Canada, joined BEA
(later British Airways). In the 1960s, he tried to see if it was possible to persuade
his flying colleagues that there was an environmental crisis ahead due to growing
population. Finding that it was impossible to locate even one person to acquiesce in
this proposition, he waited for more propitious times to engage in wider efforts. In
the 1990s, he became a member of the Optimum Population Trust (UK), started
by the late David Willey, and since 2002 has been editor of the biannual OPT
Journal.
Thomas Edgar Gangwer has a B.S. in Chemistry from Lebanon Valley College
and a PhD in Physical Chemistry from the University of Notre Dame. His ca-
reer spans basic research, applied research, regulatory compliance, and technol-
ogy implementation in the chemistry, engineering, licensing, and environmental
arenas. His materials processing experience includes chemical, radioactive, haz-
ardous, sanitary, and byproduct feed stocks and wastes. For both commercial and
government (NRC, DOE, DOD) clients, he has performed methodology devel-
opment, process modeling, process evaluation, and project/program management
covering diverse treatment, transport, pollution prevention, and disposal activi-
ties. In addition to client reports, he has over 40 scientific/technical literature

publications.
Mario Giampietro is an ICREA Research Professor at ICTA – Institute of Science
and Technology for the Environment - Universitat Autonoma Barcelona, SPAIN.
He has been visiting scholar at: Cornell University; Wageningen University; Eu-
ropean Commission Joint Research Center, Ispra; Wisconsin University Madison;
Penn State University, Arizona State University. His research addresses technical
issues associated with “Science for Governance” such as Multi-Scale Integrated
Analysis of Societal and Ecosystem Metabolism, Participatory Integrated Assess-
ment of Scenarios and Technological Changes. He has published more than 150
papers and chapters of books and is the author of: ”Multi-Scale Integrated Analysis
of Agro-ecosystems” 2003 (CRC press), and co-author of “The Jevons Paradox”
2008 (Earthscan).
Tiziano Gomiero holds a degree in Nature Science from Padua University and
a PhD in Environmental Science from the Universitat Autonoma de Barcelona,
Spain. His work concerns integrated analysis of farming systems (which takes
About our Authors xiii
into consideration the environmental, social and economic domains) and rural
development, including theoretical and epistemological issues, modeling, practical
applications (he worked in Italian and South-East Asia contexts). He is currently a
Professor of Ecology and Agroecology at Padua University.
Nathan John Hagens is currently at the Gund Institute of Ecological Economics
at the University of Vermont studying the impacts that a decline in liquid fuels
will have on planetary ecosystems and society. On the supply side, he is explor-
ing net-energy comparisons of the primary alternate fuel sources to oil: coal, wind,
nuclear and biomass. Prior to coming to the Gund Institute, Nate developed trading
algorithms for commodity systems and was President of Sanctuary Asset Manage-
ment, Managing Director of Pension Research Institute, and Vice President at the
investment firms Salomon Brothers and Lehman Brothers. He holds an undergrad-
uate degree from the University of Wisconsin and an MBA with honors from the
University of Chicago.

Charles A. Hall is a Systems Ecologist who received his PhD from Howard T.
Odum. Dr. Hall is the author of seven books and more than 200 scholarly articles.
He is best known for his development of the concept of EROI, or energy return
on investment, which is an examination of how organisms, including humans, in-
vest energy into obtaining additional energy to increase biotic or social fitness. He
has applied these approaches to fish migrations, carbon balance, tropical land use
change and petroleum extraction, in both natural and human-dominated ecosystems.
He is developing a new field, biophysical economics, as a supplement or alternative
to conventional neoclassical economics.
Edwin Kessler graduated from Columbia College in 1950 and received the Sc.D.
in Meteorology from MIT in 1957. From 1954-1961 he specialized in radar meteo-
rology with the Air Force Cambridge Research Laboratories in Massachusetts, and
from 1961-1964 he was Director of the Atmospheric Physics Division, Travelers
Research Center in Hartford, Connecticut. From 1964 until retirement in 1986, he
was Director of the National Oceanic and Atmospheric Administration’s National
Severe Storms Laboratory in Norman, Oklahoma. In 1989, he received the Cleve-
land Abbe award of the American Meteorological Society. He has been Chair of
Common Cause Oklahoma and is now Vice-Chair. He manages 350 acres of pas-
tures with woodlands and stream in central Oklahoma.
Doug Koplow is the founder of Earth Track in Cambridge, MA (www.earthtrack.
net), an organization focused on making the scope and cost of environmentally
harmful subsidies more visible. The author of Biofuels - At What Cost? Government
support for ethanol and biodiesel in the United States (Global Subsidies Initiative,
Geneva: 2006 and 2007), Doug has worked on natural resource subsidy issues for
nearly twenty years. He holds an MBA from the Harvard Graduate School of Busi-
ness Administration and a BA in economics from Wesleyan University.
xiv About our Authors
Claudia Ho Lem is currently a Project Manager for REAP-Canada’s International
Development and Bioenergy Programs. A rural development specialist with over
10 years of experience in environmental project management, Ms. Ho Lem holds a

B.Sc. in Environmental Science specializing in Biology and Chemistry from the
University of Calgary. She has worked on bioenergy, climate change and agro-
ecological development in China, the Philippines, Cuba, West Africa and Canada,
supporting farming communities in increasing their self-sufficiency through par-
ticipatory assessments, training and research. Her experience has given her an in-
tegrated understanding of the social, economic, biological, ecosystem and health
impacts of agricultural development.
Kozo Mayumi, a former student of Georgescu-Roegen, has been working in the
field of energy analysis, ecological economics and complex hierarchy theory. He
is a professor at the University of Tokushima and an editorial board member of
Ecological Economics, Organization and Environment, and International Journal
of Transdisciplinary Research. He is the author of The Origins of Ecological Eco-
nomics: The Bioeconomics of Georgescu-Roegen, published by Routledge in 2001,
and The Jevons Paradox and The Myth of Resource Efficiency Improvements from
Earthscan in 2008. Together with Dr. Mario Giampietro and three other researchers,
Mayumi started a biennial international workshop, (“Advances in Energy Studies,”)
in 1998.
Kenneth Mulder obtained his PhD in Ecological Economics from the Gund Institute
for Ecological Economics at the University of Vermont. His research is multidisci-
plinary, applying systems modeling and analysis to problems in ecology, economics
and agriculture. He is particularly interested in the development of meaningful
indicators for alternative energy technologies. Dr. Mulder currently manages an
integrated student farm at Green Mountain College and teaches in the Environmental
Studies Department there.
Maurizio G. Paoletti is a Professor of Ecology at Padova University, Padova, Italy.
With a background in biology and human ecology, he is an internationally recog-
nized researcher in biodiversity, agroecology, entomology and ethnobiology. He has
held visiting professorships in a number of countries (Finland, China, USA and
Australia). He has organised more than ten international conferences on agroecol-
ogy, sustainable agriculture, biodiversity, and is very active in public conferences

to inform citizens on sustainability issues. Overall, he has completed 260 scientific
papers and 18 edited books.
Tad Patzek is a professor of Geoengineering at U.C. Berkeley. Prior to joining
Berkeley in 1990, he was a scientist at Shell Development, a research company
managed for 20 years by M. King Hubbert. Patzek’s current research involves math-
ematical modeling of earth systems with emphasis on fluid flow in soils and rocks.
He also works on the thermodynamics and ecology of human survival and energy
About our Authors xv
supply for humanity. Currently, he teaches courses in hydrology, ecology and energy
supply, computer science, and mathematical modeling of earth systems. Patzek is a
coauthor of over 200 papers and reports, and is writing five books.
David Pimentel is a professor of ecology and agricultural sciences at Cornell Uni-
versity, Ithaca, NY. His PhD is from Cornell University. His research spans the
fields of energy, biotechnology, sustainable agriculture, and environmental policy.
Pimentel has published more than 600 scientific papers and 25 books. He has served
on many national and government committees including the National Academy of
Sciences; President’s Science Advisory Council; U.S Department of Agriculture and
U.S. Department of Energy; Office of Technology Assessment of the U.S. Congress;
and the U.S. State Department. In 2008 he received an Honorary Doctorate from the
University of Massachusetts for his work in recognizing and publicizing critical
trends in interactions between humans and the environment.
Robert Powers is finishing a BS in Environmental Science at the State University
of New York College of Environmental Science & Forestry under Dr. Charles Hall.
He is interested in the intersection of energy and economic issues, specifically in
modeling problems to find innovative solutions. He has also started a Masters in
System Dynamics at the University of Bergen (Norway) to further develop his mod-
eling skills.
Marco Raugei obtained a Master’s degree in Chemistry and a PhD in Chemical
Sciences at the University of Siena (Italy), with a thesis on Life Cycle Assessment.
He is currently working as a researcher and consultant in Life Cycle Assessment

and Environmental Management, with active collaborations with Ambiente Italia
Research Institute (Rome, Italy), University Parthenope (Naples, Italy), Brookhaven
National Laboratory (NY, USA), Columbia University (NY, USA), and Escola Su-
perior de Commerc¸ Internacional - Universitat Pompeu Fabra (Barcelona, Spain).
He has published over 35 peer-reviewed papers in various international journals,
books and conference proceedings.
Robert Rapier has Bachelor’s Degrees in Chemistry and Mathematics, and a Mas-
ter’s Degree in Chemical Engineering from Texas A&M University. Passionate
about energy and sustainability issues, his R-Squared Energy Blog is devoted to
debate and discussion of those topics. Robert has over 15 years of experience in the
petrochemicals industry, including experience with cellulosic ethanol, gas-to-liquids
(GTL), refining, and butanol production. He holds several U.S. and international
patents, and works for a major oil company. Robert is currently based in Scotland
where he lives with his wife and three children.
Daniela Russi earned a Master’s Degree in Environmental Economics at the
University of Siena (Italy). She did an internship at the Wuppertal Institute for
Climate, Environment and Energy, in Wuppertal (Germany). She obtained a PhD in
xvi About our Authors
Environmental Sciences at the Autonomous University of Barcelona (Spain) with a
thesis on Social Multi-Criteria Evaluation (SMCE) applied to a conflict concerning
rural electrification and large-scale biodiesel use in Italy. She has published peer-
reviewed papers in international journals, and contributed to various books and con-
ference proceedings on these topics. She is presently working for the environmental
consultancy Amphos21.
Roger Samson is the Executive Director of Resource Efficient Agricultural Pro-
duction (REAP)-Canada, a charitable organization working to develop and com-
mercialize ecological solutions to energy, fibre and food production. Mr. Samson
is a leading world expert in biomass energy development. He has authored over
60 publications on bioenergy, ecological farming, and climate change mitigation
and has been working on bioenergy projects in North America, Europe, China, the

Philippines, and West Africa since 1991. His work has pioneered ecological ap-
proaches for bioenergy production and thermodynamically efficient bioenergy con-
version systems. Mr. Samson holds a B.Sc. (Crop Science) from Guelph University
and a M.Sc. (Plant Science) from McGill University in Montreal.
William Schoenberg graduated from the State University of New York College of
Environmental Science & Forestry with a Bachelors Degree in Environmental Stud-
ies. He is very interested in energy issues, especially peak oil and its ramifications
for society. He is continuing his studies at the University of Bergen, Norway in the
System Dynamics program, where he will be able to more fully explore dynamic
modeling and its ability to help society prepare for the backside of the peak oil
curve.
Luis Henrique de B. Soares is an Agronomist who graduated from Federal Uni-
versity of Rio Grande do Sul State (UFRGS, Brazil). He received a Master’s degree
in Environmental Microbiology, and his PhD in Molecular and Cellular Biology
(Biotechnology Centre, Federal University fo Rio Grande do Sul, 2003), working
on microbial enzymes for industrial applications. Dr. Soares is currently a Research
Scientist at Embrapa Agrobiologia, Rio de Janeiro, studying principally agroenergy.
The areas of his research include biofuels production and processing, enzymology,
and energy balances for the assesmenet of agroecosystem sustainability.
Ms. Bailey Stamler is the Climate Change Project Manager with REAP-Canada.
She has been working with REAP developing business plans for international
carbon trading projects using small scale biomass energy technologies in the Philip-
pines, Nigeria and Ethiopia since 2005. Ms. Bailey Stamler is experienced in bioen-
ergy and bioheat pellet potential in Canada, focusing on the use of energy crops,
agriculture and crop milling residues for heating applications. She also has expe-
rience quantifying GHG emissions, mitigation potential and relative efficiencies of
biofuels. Ms. Bailey Stamler holds B.Sc. (Environmental Science) from Laurentian
University and an M.Sc. from McGill University (Natural Resource Sciences).
About our Authors xvii
Ronald Steenblik at the time of writing was Director of Research for the Global

Subsidies Initiative (GSI) of the International Institute for Sustainable Development
(IISD). Ronald’s career spans three decades, in industry, academia, the U.S. federal
government, and intergovernmental organizations, working on policy issues related
to natural resources, the environment, or trade. Prior to joining the IISD, he was
a senior trade policy analyst in the Trade Directorate of the Organisation for Eco-
nomic Co-operation and Development (OECD), where his analyses supported the
WTO negotiations on environmental goods and services. Ronald holds degrees from
Cornell University and the University of Pennsylvania.
David Swenson is an associate scientist in economics at Iowa State University and
a lecturer there in community and regional planning as well as in the graduate pro-
gram in urban and regional planning at The University of Iowa. His primary area
of research focuses on regional economic changes and their fiscal and demographic
implications for communities. He has completed scores of economic impact studies,
and written and presented extensively on the uses of impact models for decision
making. Of late, he has scrutinized the potential community economic outcomes
associated with biofuels development in the Midwest and the Plains.
Sergio Ulgiati received an education in Physics and Environmental Chemistry. He
is a Professor of Life Cycle Assessment and General Systems Theory at Parthenope
University in Napoli, Italy. He has expertise in Energy Analysis, LCA, Environmen-
tal Accounting and Emergy Synthesis. He has published over 200 papers in national
and international journals and books. His research in LCA covers renewable and
nonrenewable energy systems (wind, geothermal, hydro, bioenergy; solar thermal
and photovoltaic, hydrogen and fuel cells; thermal fossil-powered power plant, in-
cluding cogeneration and NGCC plants), as well as zero emission technologies and
strategies (ZETS). He is the organizer and Chair of the Biennial International Work-
shop “Advances in Energy Studies.”
Segundo Urquiaga graduated in Agronomy in 1973 from the Agrarian University
“La Molina”, Lima, Per
´
u, with BSc, and defended his PhD thesis in 1982 in the

Agricultural college “Luiz de Queiroz” of the S
˜
ao Paulo State University, Piraci-
caba, S
˜
ao Paulo. In 1984 he moved to the Brazilian Corporation for Agricultural
Research (Embrapa Agrobiologia) in Serop
´
edica, Rio de Janeiro. At present he is
studying the influence of biological nitrogen fixation (BNF) on the energy balance
of several renewable energy sources such as sugar cane, soybean and elephant grass.
Urquiaga has published over 120 papers in national and international journals, and
over 50 chapters in books and conference proceedings.
Contributors
Bruno J.R. Alves
Embrapa-Agrobiologia, BR-465, Km 07, Caixa Postal 75.505, Serop
´
edica,
23890-000, Rio de Janeiro, Brazil
Robert M. Boddey
Embrapa-Agrobiologia, BR-465, Km 07, Caixa Postal 75.505, Serop
´
edica,
23890-000, Rio de Janeiro, Brazil, e-mail:
Jeroen Dooper
Resource Efficient Agricultural Production (REAP) – Canada, Box 125 Centennial
Centre CCB13, Ste. Anne de Bellevue, Quebec, Canada H9X 3V9
Andrew R.B. Ferguson
11 Harcourt Close, Henley-on-Thames, RG9 1UZ, England,
e-mail:

Tom Gangwer
739 Battlefront Trail, Knoxville, TN 37934, USA, e-mail:
Mario Giampietro
ICREA Research Professor, Institute of Environmental Science and Technology
(ICTA), Autonomous University of Barcelona , Building Q – ETSE - (ICTA),
Campus of Bellaterra 08193 Cerdanyola del Vall
`
es (Barcelona), Spain,
e-mail:
Tiziano Gomiero
Department of Biology, Padua University, Italy, Laboratory of Agroecology and
Ethnobiology, via U. Bassi, 58/b, 35121-Padova, Italy,
e-mail:
Nathan John Hagens
Gund Institute for Ecological Economics, University of Vermont, 617 Main Street,
Burlington, VT 05405, USA, e-mail:
Charles A. S. Hall
State University of New York, College of Environmental Science and Forestry,
Syracuse, New York, NY 13210, USA, e-mail:
xix
xx Contributors
Edwin Kessler
1510 Rosemont Drive, Norman, OK 73072, e-mail:
Doug Koplow
Earth Track, Inc., 2067 Massachusetts Avenue, 4th Floor, Cambridge, MA 02140,
USA, e-mail:
Claudia Ho Lem
Resource Efficient Agricultural Production (REAP) – Canada, Box 125 Centennial
Centre CCB13, Ste. Anne de Bellevue, Quebec, Canada H9X 3V9
Kozo Mayumi

Faculty of IAS, The University of Tokushima, Minami-Josanjima 1-1, Tokushima
City 770-8502, Japan, e-mail:
Kenneth Mulder
Green Mountain College, Poultney VT, USA
Marcelo Dias De Oliveira
Avenida 10, 1260, Rio Claro - SP – Brazil, CEP 13500-450,
email: dias

Maurizio G. Paoletti
Dept. of Biology, Padua University, Italy, Lab. of Agroecology and Ethnobiology,
via U. Bassi, 58/b, 35121-Padova, Italy, e-mail:
Tad W. Patzek
Department of Civil and Environmental Engineering, University of California, 425
David Hall, MC1716, Berkeley, CA 94720, USA,
e-mail:
David Pimentel
College of Agriculture and Life Sciences, Cornell University, 5126 Comstock Hall,
Ithaca, NY 15850, USA, e-mail:
Robert Powers
State University of New York, College of Environmental Science and Forestry,
Syracuse, New York, NY 13210, USA
Robert Rapier
Accsys Technologies PLC, 5000 Quorum Drive, Suite 310, Dallas, TX 75254,
USA, e-mail:
Marco Raugei
Department of Sciences for the Environment, Parthenope University of Napoli,
Centro Direzionale – Isola C4, 80143 Napoli, Italy
Daniela Russi
Autonomous University of Barcelona, Department of Economics and Economic
History, Edifici B, Campus de la UAB, 08193 Bellaterra (Cerdanyola del V.),

Barcelona, Spain
Contributors xxi
Roger Samson
Resource Efficient Agricultural Production (REAP) – Canada, Box 125 Centennial
Centre CCB13, Ste. Anne de Bellevue, Quebec, Canada H9X 3V9,
e-mail:
William Schoenberg
State University of New York, College of Environmental Science and Forestry,
Syracuse, New York, NY 13210, USA
Luis Henrique de B. Soares
Embrapa-Agrobiologia, BR-465, Km 07, Caixa Postal 75.505, Serop
´
edica,
23890-000, Rio de Janeiro, Brazil
Stephanie Bailey Stamler
Resource Efficient Agricultural Production (REAP) – Canada, Box 125 Centennial
Centre CCB13, Ste. Anne de Bellevue, Quebec, Canada H9X 3V9
Ronald Steenblik
Global Subsidies Initiative of the International Institute for Sustainable
Development, Maison Internationalle de l’Environment 2, 9, chemin de Balexert,
1219 Ch
ˆ
atelaine Gen
`
eve, Switzerland, e-mail:
David Swenson
Department of Economics, 177 Heady Hall, Iowa State University, Ames IA 50011,
e-mail:
Sergio Ulgiati
Department of Sciences for the Environment, Parthenope University of Napoli,

Centro Direzionale – Isola C4, 80143 Napoli, Italy,
e-mail:
Segundo Urquiaga
Embrapa-Agrobiologia, BR-465, Km 07, Caixa Postal 75.505, Serop
´
edica,
23890-000, Rio de Janeiro, Brazil
Chapter 1
Renewable and Solar Energy Technologies:
Energy and Environmental Issues
David Pimentel
Abstract A critical need exists to investigate various renewable and solar energy
technologies and examine the energy and environmental issues associated with
these various technologies. The various renewable energy technologies will not
be able to replace all current 102 quads (quad = 10
15
BTU) of U.S. energy con-
sumption (USCB 2007). A gross estimate of land and water resources is needed,
as these resources will be required to implement the various renewable energy
technologies.
Keywords Biomass energy · conversion systems · ethanol · geothermal systems ·
hydroelectric power · photovoltaic systems · renewable energy ·solar · wind power
1.1 Introduction
The world, and the United States in particular, face serious energy shortages and
associated high energy prices during the coming decades. Oil, natural gas, coal,
and nuclear power provide more than 88% of world energy needs; the other 12%
is provided by various renewable energy sources (Table 1.1). Oil, natural gas, coal,
and nuclear provide more than 93% of U.S. energy needs; the other 9% consists of
various renewable and non-renewable energy sources (Table 1.1).
The U.S., with slightly more than 45% of the world’s population, accounts for

nearly 25% of the world’s energy consumption (Table 1.1). On average, each Amer-
ican uses nearly 8,000 L of oil equivalents per year for all purposes, including trans-
portation, industry, heating and cooling.
The United States now imports more than 63% of its oil at an annual cost of
approximately $200 billion (USCB 2007). Projections are that within 20 years the
U.S. will be importing more than 90% of its oil. The United States has consumed
more than 90% of its proved oil reserves (Pimentel et al. 2004a). Because the U.S.
D. Pimentel
College of Agriculture and Life Sciences, Cornell University, 5126 Comstock Hall, Ithaca,
NY 15850
e-mail:
D. Pimentel (ed.), Biofuels, Solar and Wind as Renewable Energy Systems,
C

Springer Science+Business Media B.V. 2008
1
2 D. Pimentel
Table 1.1 Fossil and solar energy use in the U.S. and world (quads = 10
15
BTU) (USCB 2007)
Fuel U.S. World
Petroleum 40.1 168
Natural Gas 23.0 103
Coal 22.3 115
Nuclear 8.228
Biomass 3.030
Hydroelectric power 3.427
Geothermal and windpower 0.40.8
Biofuels 0.50.9
Total 100.9 472.7

population is growing nearly twice as fast as that of China per capita, and is adding
3.3 million to the population each year, energy resources are becoming scarce
(PRB 2006). These shortages are now contributing to greater interest in renewable
energy resources.
Diverse renewable energy sources currently provide 6.8% of U.S. needs and
about 12% of world needs (Table 1.1). In addition to energy conservation, the devel-
opment and use of renewable energy is expected to increase as fossil fuel supplies
decline and become highly expensive. Eight different renewable technologies are
projected to provide the U.S. with most of its energy in the future: hydropower,
biomass, wind power, solar thermal, photovoltaics, passive energy systems, geother-
mal, and biogas. In this chapter, I assess the potential of these 8 renewable energy
technologies, including their environmental benefits and risks, and their energetic
and economic costs.
1.2 Hydroelectric Power
Hydropower contributes significantly to world energy, providing 6% of the supply
(Table 1.1). In the United States, hydroelectric plants produce approximately 3%
or 3.4 quads of total U.S. energy (340 billion kWh) (1 kWh = 860 kilocalories
[kcal] = 3,440 BT = 3.6 megajoules), or 11% of the nation’s electricity, each year
at a cost of $0.02 per kWh (Table 1.2; USCB 2007). Development and rehabilitation
of existing dams in the United States could produce an additional 5 quads per year
(Table 1.3).
Hydroelectric plants, however, require considerable land for their water storage
reservoirs. An average of 75,000 hectares (ha) of reservoir land area and 14 trillion
L of water are required per 1 billion kWh per year produced (Table 1.2, Gleick
and Adams 2000). Based on regional estimates of US land use and average annual
energy generation, reservoirs currently cover approximately 26 million ha of the
total 917 million ha of land area in the United States (Pimentel 2001). To develop
the remaining best candidate sites, assuming land requirements similar to those in
past developments, an additional 7 million ha of land would be required for water
storage (Table 1.3).

1 Renewable and Solar Energy Technologies 3
Table 1.2 Land resource requirements and total energy inputs for construction of renewable and
other facilities that produce 1 billion kWh/yr of electricity. Energy return on investment is listed
for each technology. (See text for explanations)
Electrical energy
Technology
Land required
(ha)
Energy
input:output
Cost per
kWh ($)
Life in
years
Hydroelectric power 75,000
a
1:24 $0.02
a
30
Biomass 200,000
b
1:7
b
0.058
c
30
Parabolic troughs 1,100
d
1:5
b

0.07−09
e
30
Solar ponds 5,200
f
1:4
b
0.15
b
30
Wind power 9,500
g
1:4
h
0.07
i
30
Photovoltaics 2,800
j
1:7
j
0.25
b
30
Biogas ——
k
1:1.7−3.3
l
0.02
l

30
Geothermal 30
b
1:48
b
0.064
b
20
Coal (non-renewable) 166
b
1:8
b
0.03
b
30
Nuclear (non-renewable) 30
b
1:5
b
0.05
b
30
a
Based on a random sample of 50 hydropower reservoirs in the United States, ranging in area from
482 ha to 763,00 ha (Pimentel, unpublished).
b
Pimentel, unpublished.
c
Production costs based on 70% capacity factor (J. Irving, Burlington Electric, Vermont, personal
communication 2001).

d
Calculated (DOE/EREN 2000).
e
(DOE/EREN 2000).
f
Based on 4,000 ha solar ponds plus an additional 1,200 ha for evaporation ponds.
g
(Andrew Ferguson, Optimum Population Trust (UK), personal communication, June 16, 2007).
h
(Tyner 2002).
i
(Peace Energy 2003).
j
Calculated from DOE 2000.
k
No data available.
l
(B. Jewell, Cornell University, Ithaca, NY, personal communication 2001).
Table 1.3 Current and projected US gross annual energy supply from various renewable energy
technologies, based on the thermal equivalent and required land area
Energy technology Current (2005) Projected (2050)
Quads Million
hectares
Quads Million
hectares
Biomass 4.5
a
75
b
5 102

b
Ethanol 0.16 4 0.25
Hydroelectric power 3.9
a
26
c
533
Geothermal energy 1.7
a
0.5 1.21
Solar thermal energy <0.06 <0.01 10 11
Photovoltaics <0.06 <0.01 11 3
Wind power 0.11
a
1.00 7 8
Biogas <0.001 <0.001 0.50.01
Passive solar power 0.3
d
061
Total 10.8 107 45.9 164
a
USCB (2004–2005).
b
This is the equivalent land area required to produce 3 metric tons per hectare.
c
Total area based on an average of 75,000 hectares per reservoir area per 1 billion kilowatt-hours
per year produced.
d
Pimentel et al. (2002).
4 D. Pimentel

Despite the benefits of hydroelectric power, the plants cause major environmen-
tal problems. The impounded water frequently covers valuable, agriculturally pro-
ductive, alluvial bottomland. Sediments build up behind the dams, reducing their
effectiveness and creating another major environmental problem. Further, dams
alter the existing plants, animals, and microbes in the ecosystem (Nilsson and
Berggren 2000). Fish species may significantly decline in river systems because
of these numerous ecological changes.
1.3 Biomass Energy
Most biomass is burned for cooking and heating, however, it can also be converted
into electricity and liquid fuel. Under sustainable forest conditions in both temperate
and tropical ecosystems, approximately 3 dry metric tons (t/ha) per year of woody
biomass can be harvested sustainably (Birdsey 1992, Repetto 1992, Trainer 1995,
Ferguson 2003). Although this amount of woody biomass has a gross energy yield of
13.5 million kcal/ha, it requires an energy expense of approximately 33 L of diesel
fuel per ha, plus the embodied energy for cutting and collecting wood for transport to
an electric power plant. Thus, the energy input per output ratio for a woody biomass
system is calculated to be 1:22.
The cost of producing 1 kWh of electricity from woody biomass is about $0.06,
which is competitive with other electricity production systems that average $0.07
in the U.S. (Table 1.2) (USCB 2007). Approximately 3 kWh of thermal energy
is expended to produce 1 kWh of electricity, an energy input/output ratio of 1:7
(Table 1.2). Per capita consumption of woody biomass for heat in the United States
amounts to 625 kilograms (kg) per year. In developing nations, use of diverse
biomass resources (wood, crop residues, and dung) average about 630 kg per capita
(Kitani 1999). Developing countries use only about 500 L of oil equivalents of fossil
energy per capita compared with nearly 8,000 L of oil equivalents of fossil energy
used per capita in the United States (Table 1.1).
Woody biomass could supply the United States with about 5 quads (1.5 ×
10
12

kWh thermal) of its total gross energy supply by the year 2050, provided there
was adequate forest land available (Table 1.3). A city of 100,000 people using the
biomass from a sustainable forest (3 t/ha per year) for electricity would require
approximately 200,000 ha of forest area, based on an average electrical demand
of slightly more than 1 billion kWh (electrical energy [e]) (860 kcal = 1 kWh)
(Table 1.2).
Environmental impacts of burning biomass are less harmful than those associated
with coal, but more harmful than those associated with natural gas (Pimentel 2001).
Biomass combustion releases more than 200 different chemical pollutants, including
14 carcinogens and 4 co-carcinogens, into the atmosphere (Burning Issues 2003).
Globally, but especially in developing nations where people cook with fuelwood
over open fires, approximately 4 billion people suffer from continuous exposure
to smoke (Kids for Change 2006). In the United States, wood smoke kills 30,000
1 Renewable and Solar Energy Technologies 5
people each year (EPA, 2002). However, the pollutants from electric plants that use
wood and other biomass can be controlled.
1.4 Wind Power
For many centuries, wind power has provided energy to pump water and to run mills
and other machines. Today, turbines with a capacity of at least 500 kW produce most
of the commercially wind-generated electricity. Operating at an ideal location, one
of these turbines running at 30% efficiency can yield an energy output of 1.3 million
kWh (e) per year (AWEA 2000a). An initial investment of approximately $500,000
for a 500 kW capacity turbine operating at 30% efficiency, will yield an input/output
ratio of 1:4 over 30 years of operation (Table 1.2). During the 30-year life of the
system, the annual operating costs amount to about $50,000. The estimated cost of
electricity generated is $0.07 per kWh (e) (Table 1.2). Some report costs ranging
from $0.03 to $0.05 per kWh (Sawin 2004). These values are probably located in
favorable wind sites.
In the United States, 2502 megawatts (MW) of installed wind generators produce
about 6.6 billion kWh of electrical energy per year (Chambers 2000). The American

Wind Energy Association (AWEA 2000b) estimates that the United States could
support a capacity of 30,000 MW by the year 2010, producing 75 billion kWh (e)
per year at a capacity of 30%, or approximately 2% of the annual US electrical
consumption. If all economically feasible land sites are developed, the full potential
of wind power is estimated to be about 675 billion kWh (e) (AWEA 2000b). Off-
shore sites could provide an additional 102 billion kWh (e) (Gaudiosi 1996), making
the total estimated potential of wind power 777 billion kWh (e), or 23% of current
electrical use.
Widespread development of wind power is limited by the availability of sites
with sufficient wind (at least 20 kilometers per hour [km/h]) and the number of
wind machines that the site can accommodate. An average area for one 50 kW tur-
bine is 1.3 ha to allow sufficient spacing to produce maximum power (Table 1.2).
Based on this figure, approximately 9,500 ha of land are needed to supply 1 billion
kWh per year (Table 1.2). Because the turbines themselves only occupy approxi-
mately 2% of the area, most of the land can be used for vegetables, nursery stock,
and cattle (Natural Resources Canada 2002). However, it may be impractical to
produce corn or other grains because of the heavy equipment used in this type of
farming.
An investigation of the environmental impacts of wind energy production reveals
a few hazards. Locating the wind turbines in or near the flyways of migrating birds
and wildlife refuges may result in birds flying into the supporting towers and rotat-
ing blades. For this reason, it is suggested that wind farms be located at least 300
meters (m) from nature reserves to reduce their risk to birds. The estimated 13,000
wind turbines installed in the United States kill an estimated 2,600 birds per year
(Sinclair 2003). Choosing a proper site and improving repellant technology with
strobe lights or paint patterns might further reduce the number of birds killed.
6 D. Pimentel
Bat fatalities are another serious concern. It is projected that by 2020 annual
bat fatalities caused by wind turbines will range from 33,000 to 62,000 individuals
annually (Kunz et al. 2007). Most bat fatalities are from species that migrate long

distances and are tree roosting. Eastern U.S wind turbines installed along forested
ridgetops have the highest rate of bat kills, ranging from 15.3 to 41.1 bats per MW
of installed capacity per year (Kunz et al. 2007). Monitoring for bat and bird fatal-
ities and research for the reduction of these should be included in all wind energy
planning.
The rotating magnets in the turbine electrical generator produce a low level
of electromagnetic interference that can affect television and radio signals within
2–3 km of large installations (Sagrillo 2006). Fortunately, with the widespread use
of cable networks or line-of-sight microwave satellite transmission, both television
and radio are unaffected by this interference.
The noise caused by rotating blades is another unavoidable side effect of wind
turbine operation. Beyond 2.1 km, however, the largest turbines are inaudible even
downwind. At a distance of 400 m, the noise level is estimated to be about 60 deci-
bel, corresponding roughly to the noise level of a home air-conditioning unit.
1.5 Solar Thermal Conversion Systems
Solar thermal energy systems collect the sun’s radiant energy and convert it into
heat. This heat can be used directly for household and industrial purposes or produce
steam to drive turbines that produce electricity. The complexity of these systems
ranges from solar ponds to electricity-generating parabolic troughs. In the following
analyses, I convert thermal energy into electricity to facilitate comparison to the
other solar energy technologies.
1.5.1 Solar Ponds
Solar ponds are used to capture radiation and store the energy at temperatures of
nearly 100 degrees Celsius (
◦
C). Constructed ponds can be made into solar ponds by
creating a layered salt concentration gradient. The layers prevent natural convection,
trapping the heat collected from solar radiation in the bottom layer of brine. The
hot brine from the bottom of the pond is piped out to use for heat, for generating
electricity, or both.

For successful operation of a solar pond, the salt concentration gradient and the
water level must be maintained. A solar pond covering 4,000 ha loses approximately
3 billion L of water per year (750,000 L/ha per year) under arid conditions (Tabor
and Doran 1990). Recently, solar ponds in Israel have been closed because of such
difficulties. To counteract the water loss and the upward diffusion of salt in the
ponds, the dilute salt water at the surface of the ponds has to be replaced with fresh
water and salt added to the lower layer (Solar Pond 2007).