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This century, the United States faces two serious and related threats. The first is the abnormally high atmospheric carbon dioxide concentration due to anthropogenic causes. The second is an inadequate domestic fossil fuel supply that will lead to shortages, and likely warfare, later this century. This book begins by defining these two threats to establish why America now needs to transition, this century, from non-sustainable fossil fuels to sustainable energy. The book continues by evaluating the domestic options for sustainable energy. Each of the three primary terrestrial options—nuclear, wind, and solar—are quantitatively assessed and found to be impractical solutions at the scale needed to replace fossil fuels. The book then examines what will be required to use geostationary Earth orbit (GEO) space solar power—astroelectricity—to replace fossil fuels and the cultural and military implications of transitioning to sustainable energy. The book concludes with a call for American engineers to advocate establishing a national astroelectricity program and explains why American engineers have a clear ethical obligation to undertake this advocacy.
James Michel Snead, PE Astroelectricity
Why American engineers should advocate
for GEO space solar power to end
Americas CO2 emissions, make America
energy secure, and prepare America for
the 22nd century
James Michael Snead
Professional Engineer
Spacefaring Institute LLC
James Michael Snead, PE
Copyright © 2019 by James Michael Snead.
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Portions of this book were previously published in the
author’s American Institute of Aeronautics and Astronautics
(AIAA) technical conference paper, “Why the AIAA Should
Advocate for GEO Space Solar Power”, copyright © 2018 by
James Michael Snead.
Book Layout ©2017
Published by the Spacefaring Institute™ LLC
Astroelectricity/James Michael Snead1st ed. ebook
ISBN 978-1-7329914-0-8
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Notes to Readers
This book reflects the opinion, estimates, and calculations of
the author. The author makes no warranty, express or
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accuracy, completeness, or usefulness of any information
contained in this book. All errors and omissions are the
responsibility of the author.
The manuscript for this book was written using Microsoft
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James Michael Snead, PE
This century, the United States faces two serious and related
threats. The first is the abnormally high atmospheric carbon
dioxide concentration due to anthropogenic causes. The
second is an inadequate domestic fossil fuel supply that will
lead to shortages, and likely warfare, later this century. This
book begins by defining these two threats to establish why
America now needs to transition, this century, from non-
sustainable fossil fuels to sustainable energy. The book
continues by evaluating the domestic options for sustainable
energy. Each of the three primary terrestrial options
nuclear, wind, and solarare quantitatively assessed and
found to be impractical solutions at the scale needed to
replace fossil fuels. The book then examines what will be
required to use geostationary Earth orbit (GEO) space solar
powerastroelectricityto replace fossil fuels and the
cultural and military implications of transitioning to
sustainable energy. The book concludes with a call for
American engineers to advocate establishing a national
astroelectricity program and explains why American
engineers have a clear ethical obligation to undertake this
This book is dedicated to these champions of GEO space solar
power whose brilliant illumination of how the world can
achieve sustainable energy security fostered my interest:
Peter Glaser, Gerald K. O’Neill, Hu Davis, and Ralph Nansen.
James Michael Snead, PE
Life is rarely a solitary journey. To my wife and life
companion, Connie, thank you for everything!
James Michael Snead, PE
Why This Book Was Written
Most American engineers have probably never heard of
geostationary Earth Orbit (GEO) space solar power. The basic
idea arose over a century ago when, at the beginning of the
20th century, a now famous Russian scientist, Konstantin
Eduardovich Tsiolkovsky, came to understand that our
civilization eventually would need to make use of
extraterrestrial resources to survive.
In 1968, the same year that the Apollo 8 mission became
the first human spaceflight beyond low Earth orbit (LEO)
reaching lunar orbit, an American engineer proposed building
large platforms in GEO to capture and convert sunlight into
electrical power and send (transmit) this power to ground
receiving stations to supply utilities with astroelectricity. The
idea took holdat least for a whilethrough detailed
scientific and engineering studies undertaken by the National
Aeronautics and Space Administration (NASA) and the
Department of Energy (DOE) in the late 1970s and 1980s.
However, while the concept was technically feasible, America
lacked the industrial base and astrologistical capabilities to
build the immense space solar power platforms in GEO.
Despite the tremendous accomplishments of the Apollo
program, the United States was not yet a true spacefaring
In 2007, 30 years later, I supported an informal study of
GEO space solar power undertaken by an organization within
the Department of Defense (DoD). Keen minds within DoD
understood the critical relationship between energy and
national security. The intent of the study was to reinvigorate
James Michael Snead, PE
the Federal Government’s interest in this concept. The
unclassified study, undertaken primarily using voluntary
contributions of non-DoD scientists and engineers, focused on
updating the earlier NASA and DOE studies. (1) My support
focused on the astrologistics infrastructure necessary to start
to undertake GEO space solar power. America’s spacefaring
industrial mastery had advanced significantly since the 1980s
to where undertaking GEO space solar power was now
At the close of the study, a small conference was held to
present the results. At the dinner, the study’s lead scientist,
Dr. John Mankins, provided an overview of the results. His
remarks caused me to focus on the broader issue of why GEO
space solar power had not become a national priority given
the benefits of achieving energy security through space-based
sustainable energy.
At the time of the earlier NASA and DOE studies, the
presumption was that space solar power would develop due
to market-driven economics. The expectation was that when
it became less expensive than conventional sources, the pull
of the marketplace would bring its adoption. Remarks by Dr.
Mankins made it clear that this would not be the case. The
intellectual leap from fossil fuels and nuclear power to space-
based power was just too great. Also, there was no pressing
commercial need. I, as have many other proponents, realized
that the marketplace would not pursue space solar power as
a purely commercial undertaking. The marketplace searches
for value, not cultural security. As long as there were
sufficient supplies of affordable fossil fuels, the
marketplaceand voterswere content.
On leaving the conference, developing a convincing
argument of “why” America needs to undertake GEO space
solar power became my priority, leaving to others the need to
resolve the remaining issues on how to technologically
undertake GEO space solar power. As an engineer, I focused
on making the “why” argument quantitatively. I presumed
that reasonable people would assess the relevant quantitative
information and follow my thinking in drawing conclusions
about what needs to be done. I was wrong, and I came to
realize that I first need to convince America’s engineers to
support GEO space solar power. Engineers would most likely
be receptive to my quantitatively-based reasoning especially
when it involves their ethical and professional obligations to
serve the public good.
By the nature of our profession, engineers are near-
sighted” in their daily professional lives. Our work’s objective
is to get a new capability operational as quickly as possible.
Outside of work to keep up-to-date on the relevant
engineering art, we engineers belong to professional
societies. Many of these professional societies also develop
new standards and practices to adopt new technologies and
Beyond this limited measure of forward leaning, few
engineers are professionally engaged in cultural
engineeringcharting our civilizations path forward. While
the daily aim is to make tomorrow better, the presumption is
that tomorrow should not be worse. Cultural disruption, and
especially not civilization’s collapse, is not thought possible
other than through nuclear warfare. Unfortunately, this
presumption is no longer valid. The world has changedand
so must engineers if our civilization is to survive the end of
affordable fossil fuels.
To avoid cultural collapse, engineers must now engage in
cultural engineeringdoing the advanced planning and
political advocacy necessary to chart a positive technological
future for our society. This book deals with one aspect of
cultural engineering: the environmental and energy security
related to America’s substantial dependence on non-
sustainable fossil fuels.
James Michael Snead, PE
The purpose of this book is to explain to America’s
engineers why they now need to become a strong public voice
advocating for GEO space solar power. If, after reading this
book, your engineering gut says that action is now needed, I
encourage you to act on your professions ethical obligation
to raise your voice in support of GEO space solar power
what I now refer to as astroelectricityand to encourage
your engineering friends and associates to do the same.
I close by forewarning engineers reading this book that
the information herein may be unsettling. You may find that
what you have been doing is no longer ethical and needs to be
changed. You may find that the challenges the engineering
profession must overcome are mind-blowing if our culture is
to avoid collapse. But, eventually, the bright future for
America that lies aheadonce an orderly transition from
fossil fuels to sustainable energy beginsis a calling that
America’s engineers cannot ignore. In past centuries,
American engineers have taken on and conquered substantial
challenges, e.g., the Erie Canal, the Transcontinental Railroad,
and the Apollo program. Certainly, big footsteps to follow
but follow we must!
James Michael (Mike) Snead, PE
Beavercreek, Ohio
Winter, 2019
BOE = Barrel of oil equivalent (1 BOE = 5.8 million Btu)
CO2 = Carbon dioxide
Endowment = An estimate of the remaining quantity of
technically recoverable domestic fossil fuels
GEO = Geostationary Earth orbit
GHz = Gigahertz
GW = Gigawatt of electrical power (1 billion watts)
GWh = Gigawatts of electrical power produced or used per
GWy = Gigawatts of electrical power produced or used per
year (365 days)
Insolation = Sunlight that reaches the Earth’s surface
kW = Kilowatt of electrical power (1000 watts)
kWh = Kilowatts of electrical power produced or used per
LEO = Low Earth orbit
MW = Megawatt (1 million watts)
per capita = The average quantity or rate of usage per person
of an identified population
PPM = A gas’s concentration in the atmosphere expressed in
parts per million by volume
psi = Pounds per square inch of pressure
sq km = Square kilometer
James Michael Snead, PE
sq m = Square meter
sq mi = Square mile
The following is an executive summary of the primary
points of discussion, findings, and conclusions of this book.
A. National Environmental and Energy Security
(See Chapters I and II)
As an industrialized nation, America’s prosperity depends
on its environmental and energy security. Both of these are
now significantly threatened.
The world’s environmental security is threatened by the
abnormally high and rising atmospheric carbon dioxide (CO2)
concentration. This concentration is now about 40 percent
greater than the natural maximum value measured over the
last 800,000 years. The CO2 concentration is believed to be
abnormally high due to, as examples, the combustion of
significant quantities of fossil fuels, land use changes due to
agriculture, and large populations of domesticated ruminant
animals. These anthropogenic causes have arisen due to the
world’s large human population and growing industrialized
culture. The environmental security threat is this: there is
no tested scientific hypothesis establishing, with
reasonable certainty, that this high and rising CO2
concentration will not bring unacceptable environmental
harm. For example, preliminary investigation finds that the
nutritional quality of many domesticated plants is declining
due to the higher CO2 concentration. Essentially, the excess
CO2 is an anthropogenic pollutant that has not been shown to
be benign. For this reason alone, an end to the use of non-
sustainable fossil fuels is inevitable.
James Michael Snead, PE
Fossil fuels provide about 80 percent of the energy
Americans consume. As the energy per capita consumed in
an industrialized culture is a primary indicator of prosperity,
America’s prosperity is substantially dependent on these non-
sustainable fossil fuels. Partially due to the rising U.S.
population, a projection of America’s fossil fuel energy needs
through 2100 indicates that America’s domestic
endowment of technically recoverable oil; natural gas;
and, possibly even, coal will be exhausted around the end
of the century. The resulting shortages of affordable energy
supplies and a return to a growing reliance on imported oil
and natural gas does not bode well for the prosperity and
security of our children and grandchildren. For this reason
alone, America’s orderly transition this century from
fossil fuels to sustainable energy is needed.
Together, the world’s environmental security and
America’s energy security logically demand that an orderly
transition from fossil fuels to sustainable energy be
B. The Avoidance of War (See Chapter III)
The need to obtain or desire to control oil resources
has been a primary cause for war since World War I. As
long as America remains substantially dependent on fossil
fuels, especially oil, this will exert substantial influence on the
allocation of federal resources to ensure America’s access to
foreign fossil fuel sources.
Insightful people understand the need to resolve the
environmental security and energy security threats by an
orderly transition to sustainable energy from non-sustainable
fossil fuels. For America, with its still significant remaining
fossil fuel endowment, it is possible for the United States to
become and remain energy independent during its transition
to 100 percent sustainable energy by 2100. Plainly speaking,
the United States has sufficient oil, natural gas, and coal
to ensure that the domestic energy needs of a growing
and prosperous American economy can be met while the
transition to sustainable energy is completed.
Undertaking this transition, as a national priority, will
segregate America’s energy security needs from its overseas
national security and foreign policy obligations and
considerations. This segregation will remove what many
now see as an inevitable trigger for future foreign
conflicts over energy in which the United States would
otherwise become involved. America’s leadership in this
peaceful transition to sustainable energy will provide a policy
and technological path for America’s friends and allies to
emulate and partner with the United States to achieve.
C. America’s Terrestrial Sustainable Energy
Options (See Chapter IV)
To replace the chemical energy liberated through the
combustion of fossil fuels, electrical energy will become the
primary energy source. By 2100, it is projected that each
American will need a continuous electrical power supply of
roughly 10 kilowattsabout the power needed to run 10
countertop microwave ovens. This electrical power supply
would satisfy all of the energy needs used for daily living and
working, as well as the energy needed to supply the goods and
services consumed.
By 2100, with its projected population increasing by about
50 percent to around 500 million, the United States would
need a continuous electrical power supply in the ballpark of
5,000 gigawatts (GW). Today, primarily generated using fossil
fuels, the United States has an equivalent continuous
electrical power supply of roughly 475 GWabout 10
percent of what will be needed by 2100.
While the United States has many terrestrial non-fossil
fuel options to generate the needed additional electricity,
most of those options have little or no significant growth
James Michael Snead, PE
potential. These include: geothermal-electricity,
hydroelectricity, tidal- and wave-electricity, and biomass.
The only three scalable terrestrial electrical power
options are nuclear fission, wind, and ground solar.
Nuclear fission
To meet the nation’s total 2100 energy needs, 5,155 1-
gigawatt nuclear fission power plants will be required.
(Each new plant is assumed to be operational 95 percent of
the time.) The United States only has sufficient natural
uranium, even when speculative resources are included, to
fuel about 100 such plants for their expected 120-year
economic lives. Using plutonium and/or U233both
suitable for making nuclear weaponsto replace natural
uranium will require that about 7,000,000 kg be bred
each year by 2100. (A nuclear weapon requires only about 7
kg of weapons-grade plutonium.) If the United States pursues
this fuel breeding solution, other nations will follow. Hence, a
limited domestic natural uranium supply, nuclear
weapon proliferation risks, safe nuclear waste disposal,
plant siting, adequate cooling water, and plant security
considerations all make a significant expansion of
nuclear fission an impractical solution to replace fossil
Wind and ground solar
Modern wind turbines now have hub heights of 110-140
meters. Such a wind turbine has the ability to provide
electrical energy to meet the total annual energy needs of
about 50 Americans in 2100. About 56 percent of the
contiguous United States could be used for commercial wind
farms. Fully populated with these newer turbines, this would
only supply about 65 percent of the total 2100 U.S. energy
need. This scale of wind power would require erecting about
6.6 million turbines on almost all flat or near-flat land
essentially, almost everywhere Americans live and work.
When using ground solar electricity in 2100, the annual
energy need of an average American could be met by about
1,650 square meters of solar farm land area in the sunny
Southwest. To meet the total annual need for 500 million
Americans in 2100 would require 825,000 square kilometers
of solar farms. In the seven southwestern states of Arizona,
California, Colorado, New Mexico, Nevada, Texas, and Utah,
only about 225,000 square kilometers are suitable for
commercial solar farms unless extensive grading of the
terrain is undertaken. If solar farms are built on all suitable
land in these seven states, these farms would provide only
about 27 percent of the total 2100 U.S. energy need.
In combination with nuclear, hydroelectricity,
geothermal-electricity, and biomass, a complete nationwide
buildout of wind farms along with building solar farms on all
suitable land in the seven southwestern states could meet the
projected total 2100 U.S. energy need. This would require
wind and ground solar farms covering almost 5 million
square kilometersabout two-thirds of the contiguous
United States. This is unlikely to be a politically-acceptable
D. GEO Space Solar Power (Astroelectricity) (See
Chapter V)
First proposed in 1968, large platforms placed in
geostationary Earth orbit (GEO) would be able to capture
sunlight, convert it into electrical power, and transmit this
power to a ground receiving stationreferred to as an
astroelectric plant. This GEO space solar power concept was
studied extensively by the National Aeronautics and Space
Administration (NASA), the Department of Energy, and U.S.
aerospace companies in the 1970s and 1980s. A baseline
design emerged that would provide 5 GW of astroelectricity
James Michael Snead, PE
per system, meeting the total energy needs of 500,000
Americans in 2100. By using sunlight in this manner,
generating the 10 kilowatts of continuous electrical power
needed per capita could be accomplished by capturing only
about 38 square meters of sunlight. This is about the floor
area of a two-car garage.
Replacing fossil fuels by 2100 will require building
about 825 of these 5-GW astroelectric systems. Within the
contiguous United States, this will require the use of about
135,000 square kilometers of land for the receiving antennas.
From a 1979 study, this would use about 17 percent of the
land then deemed suitable for such use. Overall, this would
use only about 1.8 percent of the land area in the
contiguous United States compared with nearly two-
thirds for the combined wind and ground solar solution.
GEO space solar power providing astroelectricity is the
reasonable alternative to the unwelcome transformation
of America that wind and ground solar would require.
E. America’s Coming Spacefaring Industrial
Revolution (See Chapter VI)
Undertaking GEO space solar power will require
substantial new American space power, space mining, space
manufacturing, and spacefaring logistics industries to build
and operate the needed 825 GEO space solar power systems.
(For the world, upwards of 10,000 astroelectric systems will
be required.) Using the current $5 billion cost per gigawatt for
building new nuclear fission power plants as a baseline,
building the 825 U.S. astroelectricity systems would cost in
the ballpark of $21 trillion. For the world, the cost would be,
very roughly, $250 trillion.
Undertaking GEO space solar power requires a
spacefaring industrial revolution comparable to the steam-
powered industrial revolution of the 1800s. Now
substantially barren of a human presence, outer space
will become the permanent home of tens of thousands of
Americans working and living throughout the central
solar systemin LEO and GEO, on the Moon, in lunar
orbit, at the Earth-Moon LaGrange points, and at
asteroids throughout the central solar system. Solving the
world’s environmental and energy security challenges
through an orderly transition to astroelectricity, while also
transforming America’s long-held spacefaring dream into
reality, foretells an exciting time ahead for America’s
aerospace engineers.
F. Renewing America for the 22nd Century (See
Chapter VII)
Undertaking a spacefaring industrial revolution is not the
only dramatic change America will undergo this century. With
the increasing supply of sustainable astroelectricity, America
will use this to power five transformative technologies: 3D
additive manufacturing, “lights-out” robotic factories,
intelligent recycling, construction humanoids, and intelligent
deconstruction. Together, these technologies will
substantially reduce the direct human labor in construction
and manufacturing. As a consequence, most of today’s
America will be affordably deconstructed and rebuilt
enabling us to leave our children and grandchildren a
profoundly better 22nd century Americaa renewed,
sustainable America from the ground up. Achieving this
goal will unite Americans politically while evaporating
the differences that divide us economically.
G. Why American Engineers Should Advocate for
a National Astroelectricity Program (See
Chapter VIII)
The interrelated environmental and fossil fuel energy
security threats to the United States will only be resolved
through an orderly transition to sustainable energy. To avoid
James Michael Snead, PE
civilization’s collapse later this century, American engineers
have a professional and personal moral obligation to see that
these fossil fuel energy sources are replaced in an orderly
manner to prevent energy supply disruptions. This will
require building around 5,000 GW of replacement continuous
sustainable electrical power generation capacity by 2100.
With GEO space solar power being the only practical
means of providing the bulk of this need for 5,000 GW for
new sustainable generation capacity, American
engineers should forcefully advocate for a national
astroelectricity program!
We the People of the United States, in Order to form a
more perfect Union, establish Justice, insure domestic
Tranquility, provide for the common defence, promote
the general Welfare, and secure the Blessings of Liberty
to ourselves and our Posterity, do ordain and establish
this Constitution for the United States of America.
The U.S. Constitution was adopted to create a federal
government to provide for the defense and general welfare of
Americans, then and in perpetuity. Hence, per the
Constitution, the Federal Government must act now to
secure the liberty and welfare of Americans in the
foreseeable future against acknowledged threats.
This century, Americans face two significant and related
threats due to our use of fossil fuels to substantially energize
our industrial culture. The first threat is the abnormally high
atmospheric carbon dioxide concentration. The second is
America’s substantial reliance on non-sustainable fossil fuels.
To resolve these threats, while ensuring the defense,
general welfare, and liberty of our children and
grandchildren, the Federal Government must lead
America’s orderly transition from fossil fuels to
sustainable energy this century. Of the sustainable energy
options available to the United States, only GEO space solar
power (astroelectricity) now offers the scalable potential to
replace non-sustainable fossil fuels and provide the
additional energy needed to remediate existing possible
environmental harm that our past and continued use of fossil
fuels created.
James Michael Snead, PE
Figure 1: Illustration of a future space colony. Mega
space projects such as this will be common in the later
21st century. Imagine being the chief engineer
responsible for building such a colony. (Credit: Rick
Guidice, NASA.)
Undertaking this transition to space-based sustainable
energy will require a national astronautical program of a scale
unprecedented in America’s peacetime history. By the end of
this century, Americans will be working and living in
large numbers throughout the central solar system to
provide America with the space-based sustainable
energy it will need to remain prosperous, at peace, and
free. (See Figure 1.) In the process, America will undertake
a spacefaring industrial revolution becoming a true
commercial human spacefaring nation!
Chapter I: The Anthropogenic
CO2 Environmental Threat
Over the last 800,000 years, the climate has experienced
at least eight cycles of global cooling followed by interglacial
warming. Using core drills, scientists have extracted samples
of ancient Antarctic ice formed up to 800,000 years ago. As
this ice formed, air was trapped within the ice in small
bubbles enabling the atmospheric carbon dioxide (CO2)
concentration in these ancient air samples to be measured.
The CO2 concentration is expressed as parts per million (PPM)
by volume. As shown in Figure 2, across the past 800,000
years, the pre-industrial CO2 concentration has naturally
varied from a low of about 185 PPM, during periods of
global cooling, to a high of about 300 PPM during periods
of interglacial warming.
Note: For most of the past several million years, the
Earth has been much colder with most of the northern
hemisphere largely covered with glacial ice. The
Earth’s surface temperature that is now viewed as
“normal” is actually abnormally warm. Hence, the
uncertainty surrounding the question of what
constitutes a normal global average temperature is
why this book focuses on the atmospheric CO2
concentration and not the uncertainty surrounding
“global warming”.
James Michael Snead, PE
Figure 2: Atmospheric CO2 concentration (parts per
million by volumePPM) from 800,000 years ago to
about 17,000 years ago from ice core measurements.
(Data source: World Data Center for Paleoclimatology,
Boulder, and NOAA Paleoclimatology Program,
retrieved 2016 and 2017. Credit: J. M. Snead.)
Beginning in the early 1800s in America, the emerging
industrial culture and the rapidly growing American
population began to consume energy at non-sustainable
rates. The remaining old growth forests began to be clear cut
to meet the demands for timber, sawn lumber, and wood fuel
in addition to clearing land for agriculture. Starting in the
1830s, coal began to be commercially mined to replace wood
fuel where wood fuel shortages developed. By the 1880s, coal
became the predominant energy source as the nation’s wood
fuel supply began to wane.
As a carbon-based fuel, the combustion of wood yields
CO2. All living creatures also release CO2. Once released into
the atmosphere, a CO2 molecule is believed to have a resident
time of up to a century before it is removed through plant
growth or absorbed into the oceans, eventually largely ending
up as rock. Across at least eight cycles of global cooling and
warming, for yet unexplained reasons, the maximum
natural CO2 concentration always fell within the range of
244-299 PPM. (See Figure 2.) Hence, up until the early
decades of the Industrial Age, the total release of CO2 and its
removal through natural means remained in general balance,
even as the climate naturally changed.
The growth of our human population has brought large-
scale land use changes worldwide and an increasing demand
for combustible fuels. These changes have increased the
release of CO2. Around 1900, the atmospheric CO2
concentration increased above the natural maximum of
the preceding 800,000 years. (See Figure 3.) Analysis of
changes in the isotopic proportions of the carbon in the CO2
indicates that this increase is primarily due to the combustion
of plant-based fuelswood and fossil fuels. Today, the CO2
concentration is above 400 PPM, climbing each year. This
roughly 33 percent increase above the natural maximum
has occurred because anthropogenic CO2 release has
increased the total CO2 release rate beyond what nature
is capable of removing from the atmosphere. Essentially,
this excess CO2 is an anthropogenic pollutant.
Note: While not settled science, changes in the
atmospheric CO2 proportions of C12, C13, and C14,
since the beginning of industrialization, are believed to
be evidence that the combustion of fossil fuels is the
primary source of the excess atmospheric CO2. There
may also be other significant sources due to other
anthropogenic causes such as land use changes,
agricultural plant selection, and large numbers of
domesticated ruminants.
James Michael Snead, PE
Figure 3: Industrial era atmospheric CO2
concentration, 1700-2015. (Climate data source:
World Data Center for Paleoclimatology, Boulder, and
NOAA Paleoclimatology Program, 1700-1958,
retrieved 2015 and 2016; NOAA/Mauna Loa, Hawaii,
1959-2015, retrieved 2016.) World population
estimate. (Data source: U.S. Census Bureau.) Carbon
emissions from fossil fuels. (Data source: U.S.
Department of Energy’s Carbon Dioxide Information
Analysis Center and BP’s Statistical Review of World
Energy as compiled by the Earth Policy Institute.
Credit: J. M. Snead.)
While once we ignored anthropogenic pollution, today we
seek to eliminate it. For today’s excess CO2, there is no
scientific certaintyno tested hypothesisthat the
abnormally high CO2 concentration will not harm the
environment. In fact, preliminary scientific investigations into
possible changes have found that the nutritional quality of
many of the plants on which our agriculture depends is being
reduced by the increasing CO2 concentration. (2) (3) (4)
Obviously, besides impacting our food supply, this will also
likely impact the nutritional quality of the plants on which all
living creatures depend. Hence, there is good reason for
caution and concern.
Note: Key elements, such as zinc and iron, are reduced,
as is the production of protein. Plants affected include
wheat, rice, corn, potatoes, and field peas. In wheat and
rice, protein production declined about 7 percent when
grown in CO2 concentrations twice that of pre-
industrial levels.
The lack of scientific certainty that the abnormally high
CO2 concentration is not causing harm constitutes an
environmental security threat. Essentially, the excess
anthropogenic CO2 should be recognized as a pollutant that
requires remediation because we do not have positive
knowledge that the excess concentration is environmentally
benign. The first step to address this threat is to end the use
of fossil fuels. The second step is to technologically remove
the excess CO2 from the environment to return the
atmospheric concentration to, at least, the maximum natural
safe level of 300 PPM.
To undertake the first step, the United States must
develop sufficient non-fossil fuel energy sources to
replace fossil fuels. For the second step, additional non-
fossil fuel energy sources must be built to provide the energy
necessary to capture CO2 from the atmosphere; to reform the
captured carbon into synthetic coal, oil, and methane; and, to
permanently geologically store these synthetic fossil fuels
underground in empty coal mines and oil and gas reservoirs.
Note: Given sufficient time, once fossil fuel CO2
emissions end, nature will remove the excess
James Michael Snead, PE
atmospheric CO2 with this eventually ending up as rock
or buried bogs. Of course, this may take thousands of
years. While we could simply wait for this to happen,
the better choice is to extract the excess atmospheric
CO2 and use it to create a synthetic fossil fuel reserve,
geologically stored, that would be available if needed in
the future. This could feasibly be done once our energy
supply becomes free of fossil fuels.
Chapter II: America’s Fossil
Fuel Energy Security Threat
At first glance, resolving the CO2 environmental threat
would appear to be a political choice of whether to continue
to use fossil fuels or not. It is not that simple. Because fossil
fuels are non-sustainable, the supply of affordable fossil fuels
will inevitably end. The three key national energy security
questions addressed in this and the following sections are:
1. When will these supplies become undependable?
2. What will replace oil, natural gas, and coal?
3. When should the transition to replacement energy sources
be completed to avoid serious economic disruptions and the
threat of war?
James Michael Snead, PE
Figure 4: U.S. historical total energy use, 1850-2015,
and projected energy need, 2016-2100, with breakouts
for fossil fuel (black) and non-fossil fuel energy
(green). (Historical data source: U.S. Energy
Information Administration. Credit: J. M. Snead.)
Figure 4 shows America’s fossil fuel (black) and non-fossil
fuel energy (green) historic use from 1850-2015 and the
author’s projection of America’s future energy need through
2100. The energy unit is the barrel of oil equivalent or BOE.
Note: When crude oil was still shipped in wooden
barrels in the late 1800s, a barrel containing 42 U.S.
gallons was adopted as the standard for measuring oil.
Since oil is primarily used as a fuel, a barrel of oil was
later defined in terms of the average energy available
rather than the physical volume. A barrel of oil
equivalent (BOE) is now set as equaling 5.8 million
British thermal units (Btu) of gross thermal energy. By
using energy and not volume, all methods of producing
or consuming energy can be expressed in terms of the
equivalent BOEeven electrical sources such as
nuclear power and hydroelectricity.
For the 2016-2100 projection, each year’s annual energy
need is simply the product of the population size and the per
capita energy need. To prepare this projection, the author
assumes that the U.S. population will likely grow to 500
million by 2100 and, that over this period, new technologies
will reduce the per capita energy need to 50 BOE per year in
1. In 1999, the U.S. Census Bureau projected the likely
U.S. population in 2100 at 571 million. Since then,
various projections have indicated a likely lower value.
The 500 million value used is representative of these
later projections. Most of this population increase will
be due to continued net international migration to the
United States.
2. The historic peak U.S. per capita energy use was 62.2
BOE per year in 1979, just prior to the oil supply crisis
resulting from the diplomatic consequences of the
Iranian Revolution. During the subsequent 20 years,
per capita demand declined only by 3.5 percent overall
despite strong efforts encouraging energy
conservation and improved energy efficiency. During
good economic times when energy prices are
affordable, technology improvement is the only
practical way to permanently reduce per capita energy
use. Hence, the author assumes a further decline to 50
BOE per year in 2100 due to continued improved
energy efficiency, making a total decline of about 20
percent from 1979.
In 2015, fossil fuels provided 82 percent of the total
energy Americans consumed. Holding this percentage
James Michael Snead, PE
constant, Figure 4 shows that the United States will need
1,540 billion BOE of fossil fuels through 2100 (with,
obviously, more in the 22nd century). From this projection,
the United States will require a total affordable fossil fuel
supply through 2100 that is about 50 percent greater
than the total fossil fuels Americans consumed since
1850. Is this reasonable? We can address this question by
looking at how much affordable domestic fossil fuels
remainwhat is referred to as the domestic fossil fuel
During 2014-2016, the U.S. Geological Survey released
(through the U.S. Energy Information Administration) an
estimate of the remaining U.S. endowment of technically
recoverable oil, natural gas, and coal. As seen In Table 1, the
remaining fossil fuel endowment is estimated to hold
1,592.1 billion BOE. Of this total, 17 percent is oil, 28
percent is natural gas, and 55 percent is coal.
Table 1: United States remaining technically
recoverable fossil fuel endowment.
Table 1 notes:
1. U.S. Energy Information Administration, Table 9.1,
Technically recoverable U.S. Crude oil resources as of
January 1, 2014, Chapter 9, Oil and Gas Supply Module,
Assumptions to the Annual Energy Outlook 2016, page
132, January 2017.
2. U.S. Energy Information Administration, Table 9.2,
Technically recoverable U.S. dry natural gas resources
as of January 1, 2014, Chapter 9, Oil and Gas Supply
Module, Assumptions to the Annual Energy Outlook
2016, page 133, January 2017.
3. U.S. Energy Information Administration, Table 15,
Recoverable Coal Reserves at Producing Mines,
Estimated Recoverable Reserves, and Demonstrated
Reserve Base by Mining Method, Annual Coal Report
2015, November 2016.
4. 1 cu. ft. natural gas = 1,028 Btu; 1,000,000 cu. ft. =
177.2 BOE; 1 short ton of coal = 19.988 million Btu; 1
short ton = 3.45 BOE.
It is important to understand that this endowment
estimate includes both proven reserves and unproven
resources. Only 14 percent of the oil and natural gas
endowments are “proven reserves”—meaning there is high
confidence in bringing these estimated quantities to market.
The other 86 percent is based on expert judgement that one
government report acknowledges as being “highly uncertain”.
Thus, the total endowment represents a ballpark estimate
that is mostly a guestimatean important point to keep in
James Michael Snead, PE
Figure 5: Annual energy consumption in the United
States by type, 1950-2015. (Data source: U.S. Energy
Information Administration. Credit: J. M. Snead.)
Figure 5 shows the historical consumption of energy in the
United States from 1950-2015. The numeric value of the
consumption in 2015 for each type of energy is shown in the
right column. These values are shown in billion BOE per year.
Note: Since about 1970, the United States has imported
significant quantities of oil and natural gas. Thus, the
total energy consumed exceeds what was produced
domestically. The United States has not been energy
secure since about 1970.
Using these 2015 oil, natural gas, and coal consumption
rates, a rough estimate of the remaining life of the oil, natural
gas, and coal endowments shown in Table 1 can be made. For
each fuel, the endowment size is divided by the 2015
consumption rate to yield a rough estimate of how long the
supply of that fuel would last at the 2015 rate. These
calculations are summarized in Table 2.
Table 2: Estimate of the years of life of America’s
remaining fossil fuel endowment from 2016 using
2015 consumption rates. Quantities are expressed in
billion BOE and rates are expressed in billion BOE per
year. The 2015 consumption rates come from Figure 5.
Therefore, these estimates do not include the impact of
the likely 50 percent increase in the total energy
needed annually by 2100 due to expected population
Assuming that only domestic sources are usedwith no
imports or exportsthe domestic oil and natural gas
endowments will last, respectively, about 45 years and about
90 years. Coal would last over 300 years primarily because, as
shown in Figure 5, coal consumption has declined
significantly since 2008 when fracking significantly increased
the supply of natural gas.
In 2015, the U.S. population was about 320 million. The
expected population increase to 500 million by 2100
represents a 56 percent increase in population size. With this
anticipated population growth and the associated increased
total U.S. energy needs, the fossil fuel endowment life
estimates in Table 2 will be reduced. Thus, Table 2 provides
an optimistic estimate of the remaining life of domestic fossil
From these life estimates, reasonable people understand
that a continued U.S. dependence on affordable fossil fuels
represents a clear national energy security threat to
America’s future economic prosperity and national security.
James Michael Snead, PE
At some point, the United States will need to import
substantial oil and natural gas just as it was doing from 1970-
2008 prior to the “fracking” revolution. The national security
implications of such a change are obvious, with the likelihood
of the threat of war being significant. The United States is not
alone among industrialized nations linking assured supplies
of fossil fuels to their national security. (See Figure 6.)
Figure 6: One of many artificial islands China is building
in the South China Sea to enable China to expand its
military and economic power projection abilities. Not
only does this strengthen China’s competition for
energy resources under the South China Sea, but it also
expands their airborne and seaborne military power
projection over fisheries and seaborne trade routes
carrying one-third of the world’s shipping. (Credit: U.S.
Chapter III: The Rational Path
Forward for the United States
The U.S. Constitution requires that the President and
Congress address threats to domestic tranquility, national
defense, and the general welfare of Americans. America’s
continued substantial dependence on fossil fuels has
created environmental and national security threats
warranting a federal response. The only rational path
forward is for the United States to end its use of fossil
fuels. However, doing so must not be rash, as some appear to
desire, but done in an orderly manner. The starting point is to
establish a target for when the transition from fossil fuels
must be accomplished.
The United States became a party to the international
treaty, The United Nations Framework Convention on Climate
Change (UNFC3), when it was consented to by the U.S. Senate
in 1992. This means that the treaty carries the weight of U.S.
law. One objective of this treaty is to mitigate possible
environmental harm arising from anthropogenic greenhouse
gas emissions, including CO2.
In 2015, the Paris Climate Agreementthe latest protocol
intended to implement the treatywas signed by President
Barrack Obama. While it fails to define an effective
technological means of addressing CO2, one important aspect
was to establish the year 2100 as the goal for ending fossil fuel
use. Thus, setting 2100 as the target for ending America’s use
of fossil fuels would be consistent with an apparent primary
goal of the Agreement.
James Michael Snead, PE
1. The Paris Climate Agreement was not submitted to
the U.S. Senate for advice and consent. Thus, it is not a
2. The Paris Climate Agreement is often vague. For
example, it does not mention carbon dioxide.
3. Article 4 of the Agreement alludes to the completion
of the mandated climate change mitigation efforts in
the second half of the century, interpreted here to
mean by 2100.
Figure 7: U.S. historical total energy use, 1850-2015,
and transition to 100 percent sustainable energy by
2100. (Historical data source: U.S. Energy Information
Administration. Credit: J. M. Snead.)
The impact of setting 2100 as the target for ending
America’s use of fossil fuels is shown in Figure 7. In this figure,
the U.S. consumption of fossil fuels is assumed to climb until
2035 when it peaks at about 17 billion BOE. From 2035-2100,
fossil fuel use then declines as a national program to replace
fossil fuels with sustainable energy is implemented. The
period up until 2035 would be used to define the replacement
sustainable energy strategy, obtain political consensus,
undertake needed studies and reviews, pass enabling
legislation, define needed regulation, and begin to build any
necessary sustainable energy-enabling infrastructure.
Also shown in Figure 7, with this transition approach, the
United States will need to consume in the ballpark of 867
billion BOE of fossil fuels through 2100. This is about as much
fossil fuels as the U.S. fossil fuel industry domestically
produced since 1850.
The 867 billion BOE can be divided into the amounts of oil,
natural gas, and coal needed by using the 2015 consumption
percentages for each of these fuels from Table 2. As shown in
Table 3, the United States would need roughly 386 billion BOE
of oil, 310 billion BOE of natural gas, and 171 billion BOE of
coal through 2100. These values are compared to the
estimated remaining technically recoverable endowment for
each fuel type shown in the last column.
Table 3: Estimates of how much oil, natural gas, and
coal will be needed through 2100 taking into account a
projected increase in the U.S. population to 500 million
by 2100. The 2015 consumption percentages for each
fuel type, from Table 2, are held constant. Quantities
are expressed in billion BOE; consumption rates are
expressed in billion BOE per year.
James Michael Snead, PE
As seen in Table 3, the coal needed through 2100 is
substantially less than the remaining coal endowment. Hence,
having sufficient coal is not an issue. The same is true for
natural gas, assuming no exports. However, the demand for
oil would exceed the estimated remaining oil endowment.
As oil and natural gas are increasingly interchangeable
when used as transportation fuels, their combined total of
696 billion BOE needed through 2100 is also shown in Table
3. From the last column of Table 3, the remaining estimated
oil plus natural gas endowment totals 713 billion BOE. Thus,
the need for oil and natural gas is about equal to the total
estimated to remain in the endowment. Therefore, by
modestly increasing the use of natural gas as a
transportation fuel to meet any shortfall in oil, while also
increasing the use of electric vehicles powered using
electricity generated by renewables, nuclear, natural gas,
and coal, the United States could become completely
energy independent foreverprovided it undertakes an
orderly transition to sustainable energy this century.
With this orderly transition approach from fossil fuels to
sustainable energy, four important political considerations
are evident:
1. The United States will still need a robust domestic fossil fuel
industry for most of the rest of this century to enable an
orderly transition to sustainable energy while avoiding
foreign entanglements through the need to import oil or
natural gas. (See Figure 8.) One important consequence is that
the political war of fossil fuels versus sustainable energy
vanishes, thereby removing a contentious issue from the
national political debate.
Figure 8: U.S. fighters flying over burning Kuwaiti oil
wells at the end of the Gulf War in 1991. (Credit: U.S.
Government work.)
2. With the prudent management of America’s remaining
fossil fuel endowment, the United States should be able to
rapidly achieve and maintain domestic fossil fuel energy
independence throughout this period of transition. This
would substantially change America’s national security risks
and provide significant domestic economic and foreign policy
James Michael Snead, PE
3. The United States would be faithful in responding to the
primary objective of the UNFC3 treaty, as well as the broad
goal of the Paris Agreement, to end the use of fossil fuels by
the end of the century. This would eliminate the
contentious CO2 environmental issue from both domestic
and international political discussions as well as possible
legal challenges.
4. The United States would become a world leader in the
movement to a sustainable culture by the 22nd century. This
will bring significant economic and political benefits to the
United States.
Chapter IV: America’s
Sustainable Energy Options
Recall that the annual American per capita energy need in
2100 is assumed to be 50 BOE. Further, recall that fossil fuels
account for about 82 percent of the energy now consumed in
America. As was seen in Figure 4, without any change in the
percentage of fossil fuel use, the expected 500 million
Americans in 2100 will need an annual energy supply
equivalent to 25 billion BOE20.4 billion BOE of fossil fuels
and the equivalent of 4.6 billion BOE supplied by non-fossil
fuel sources. Consequently, to complete the transition from
fossil fuels by 2100, new sustainable energy supplies
providing the equivalent of about 20 billion BOE
enough for 400 million Americanswill be needed. This
defines the magnitude of the challenges facing American
engineers: how to replace today’s relatively easy-to-
obtain fossil fuels with the equivalent of 20 billion BOE
per year of new sustainable energy supplies.
America’s terrestrial non-fossil fuel energy sources
include: nuclear fission, wind, active ground solar, passive
solar, hydroelectric, geothermal-electric, tidal- and wave-
electric, and biomass. Of these options, only the following
three have the potential to be scaled up sufficiently to
replace fossil fuels:
Nuclear power
Wind power
Ground solar power
James Michael Snead, PE
Each of these three options will be evaluated to assess the
practicality of using them to substantially replace fossil fuels.
The starting point is to establish America’s 2100 energy needs
in terms of electrical energy rather than BOE.
A. Defining America’s electrical energy
needs in 2100
With the transition from fossil fuels, electricity will
become the fundamental energy source. Based on the
above 2100 energy needs analysis, the assumed 2100 per
capita energy need will be expressed in terms of the
equivalent kilowatt-hours (kWh) of baseload electrical
energy. (See Appendix A.)
2007 baseline per capita energy consumed
The selected baseline year is 2007just prior to when per
capita energy use started to decline in 2008 at the start of the
prolonged recession. In 2007, 37.4 percent of the total energy
consumed was used to generate electricity. The remaining
62.6 percent36.2 BOEwas consumed by the end users as
fuels. In 2007, the energy used to generate electricity
produced 13,781 kWh of electrical energy per capita.
Hydrogen: the assumed 2100 sustainable fuel
In the following analysis, by 2100, hydrogen, produced by
the electrolysis of water, is assumed to be the only
combustible fuel. Hydrogen would replace oil, natural gas,
and coal for industrial processes requiring a combustible fuel
and for commercial and consumer uses such as
transportation fuel. It is assumed that hydrogen would be
distributed nationally through a hydrogen pipeline network
much as natural gas and petroleum are distributed today.
1. While technology advancements are being made to
enable the direct consumer use of hydrogen, primarily
for fueling cars, the wide scale adoption of this as a
general consumer fuel is problematic. Hydrogen is
extremely flammable, with hydrogen concentrations in
air as low as 4 percent being ignitable. Further, with the
required ignition energy being very low and a
hydrogen flame being very hard to see, accidental fires
and burns are very likely.
2. Due to such safety considerations, by 2100, the likely
general consumer fuel will be a synthetic methane
CH4with a synthetic liquid fuel used where needed,
such as for aviation. In this manner, the safety and
convenience of today’s use of fossil fuels can be
continued without producing net anthropogenic CO2
3. The starting point in the production of these
synthetic fuels will be the electrolysis of water using
sustainable electricity to produce hydrogen. Carbon
extracted from atmospheric CO2 would then be
combined with hydrogen to yield the synthetic
methane or a synthetic liquid fuel. With this approach,
the atmosphere becomes the conduit to return carbon
for reuse so that the anthropogenic rise in atmospheric
CO2, due to the combustion of carbon fuels, ends. As
mentioned previously, additional synthetic methane
and liquid fuel could be produced and injected into
geological storage in dry natural gas and oil wells to
reduce the overall atmospheric CO2 concentration and
to create an emergency energy reserve.
4. Significant research is underway to identify energy-
efficient ways to produce synthetic carbon fuels from
hydrogen and CO2. Key advancements in catalysts are
being made that could significantly reduce the
James Michael Snead, PE
additional energy required to prepare these synthetic
fuels. However, due to the uncertainty of the additional
energy that will be required, this additional energy is
not included in these calculations. Given the
uncertainty associated with other assumptions used
population size, future per capita energy use,
electrolyzer efficiency, etc.this is not believed to be a
significant shortcoming for this top-level analysisbut
a point to be aware of.
2100 per capita energy needs
The per capita energy need for 2100 is assumed to be 50
BOE86.6 percent of the 2007 rate and about 80 percent of
the historical peak rate in the 1970s. After applying this
adjustment, while maintaining the 2007 percentages of
energy used as fuels and electricity, 31.324 BOE of hydrogen
fuel and 11,932.073 kWh of dispatched electrical energy will
be needed per American in 2100. (See Appendix C.)
The author has estimated, using U.S. Energy Department
projected future electrolyzer efficiencies, that 2,358.396 kWh
of electrical energy will be required to produce one BOE of
hydrogen fuel yielding the fuel’s lower heating value. (See
Appendix B.) Thus, 73,874 kWh of electrical energy will be
required to produce and deliver 31.324 BOE of hydrogen fuel.
𝟐, 𝟑𝟓𝟖.𝟑𝟗𝟔 𝒌𝑾𝒉
×𝟑𝟏.𝟑𝟐𝟒 𝑩𝑶𝑬𝑳𝑯𝑽
=𝟕𝟑,𝟖𝟕𝟒 𝒌𝑾𝒉
In total, to provide the equivalent of 50 BOE of gross
thermal energy in 2100, 85,806 kWh of continuous (baseload)
electrical energy will be needed per capita in 2100.
+ 73,874
= 85,806
1. The useful work produced by the combustion of a
fuel depends on how efficiently the heat released by
combustion is used. For general use, such as in an
automobile, the lower heating value of the fuel is
assumed. This means that some possibly useful heat is
lost through the exhaust. In this analysis, the higher
heating value is used only for advanced technology
electricity generation where the primary waste heat is
used as a secondary heat source to generate additional
electricity. For hydrogen, the difference between these
two heating values is significant warranting
incorporation of this difference into these estimates.
For carbon fuels, the difference is less and generally
2. The 2,358 kWh estimate includes the additional
electrical energy required to compress the hydrogen
gas to 1200 pounds per square inch (psi) for injection
into a hydrogen pipeline distribution system. An
energy allowance is also included for a portion of the
hydrogen to be further compressed for use as a
transportation fuel.
Total American energy need in 2100
As discussed, the 2100 per capita need for 50 BOE per year
of fossil fuels equates to 85,806 kWh of electrical energy per
year. Using this value, the continuous electrical power need is
for 9.8 kW.
𝟖𝟓,𝟖𝟎𝟔 𝒌𝑾𝒉
𝟑𝟔𝟓 𝒅𝒂𝒚𝒔 × 𝟐𝟒 𝒉𝒐𝒖𝒓𝒔
= 𝟗. 𝟖 𝒌𝑾 (𝒄𝒐𝒏𝒕𝒊𝒏𝒖𝒐𝒖𝒔)
On a per capita basis, the needed continuous electrical
power in 2100 would be about 10 kilowatts (kW)
enough to operate 10 countertop microwave ovens. Thus, 50
James Michael Snead, PE
BOE per year is equivalent to the power used by 10
microwave ovens running continuously.
For the assumed American population of 500 million in
2100, a total of 5.996 million gigawatt-hours (GWh) of
electrical energy for direct use and 15.65 billion BOE of
hydrogen fuel will be needed.
𝟏𝟏,𝟗𝟑𝟐 𝒌𝑾𝒉
𝒚𝒆𝒂𝒓 ×𝟓𝟎𝟎 𝒎𝒊𝒍𝒍𝒊𝒐𝒏
𝟏 𝒎𝒊𝒍𝒍𝒊𝒐𝒏 𝒌𝑾
= 𝟓, 𝟗𝟔𝟔,𝟎𝟎𝟎 𝑮𝑾𝒉
× 500
= 15,650,000,000
In terms of total electrical energy, America will need to
generate 42.9 million GWh of continuous electrical
energy in 2100. For perspective, this is roughly 10X the total
electrical energy generated in America in 2007.
𝟖𝟓,𝟖𝟎𝟔 𝒌𝑾𝒉
𝒚𝒆𝒂𝒓 ×𝟓𝟎𝟎 𝒎𝒊𝒍𝒍𝒊𝒐𝒏
𝟏 𝒎𝒊𝒍𝒍𝒊𝒐𝒏 𝒌𝑾
=𝟒𝟐,𝟗𝟎𝟑,𝟎𝟎𝟎 𝑮𝑾𝒉
America will need 4,897.6 GW of continuous generating
capacity in 2100.
𝟒𝟐,𝟗𝟎𝟑,𝟎𝟎𝟎 𝑮𝑾𝒉
𝟑𝟔𝟓 𝒅𝒂𝒚𝒔
𝒚𝒆𝒂𝒓 ×𝟐𝟒 𝒉𝒐𝒖𝒓𝒔
= 𝟒, 𝟖𝟗𝟕.𝟔 𝑮𝑾
B. Nuclear power
Figure 9: Nuclear power plant being built in the 1970s.
The nuclear reactor is in the middle. The two tall
cylinders are the heat exchangers to convert the
nuclear heat, released in the reactor, into steam to
power the turbines generating electricity. The outer
concrete walls are part of the containment building.
The rectangular chamber in the upper right will be the
holding pond where old fuel assemblies are kept under
water to cool down after being removed from the
reactor. (Credit: U.S. government work.)
Number of 1-GW nuclear power plants needed
in 2100
A typical new nuclear power plant is sized to generate
about 1 billion watts or 1 gigawatt (GW) of electrical power.
James Michael Snead, PE
(See Figure 9.) In this case, the “nameplate” power rating is 1
GW. A new nuclear power plant is expected to have a 120-year
operational lifetime.
No nuclear or fossil fuel power plants operate
continuously. In this analysis, the percentage of the total time
that a new nuclear plant is operating each yearreferred to
as the plant’s capacity factor—is assumed to be 95 percent.
This means that the plant would be shut down about 3 weeks
each year for refueling and scheduled maintenance.
A 1-GW nuclear plant operating with a 95 percent capacity
factor will generate 8,322 GWh of electrical energy each year.
𝟏 𝑮𝑾 ×𝟑𝟔𝟓 𝒅𝒂𝒚𝒔
𝒚𝒆𝒂𝒓 ×𝟐𝟒 𝒉𝒐𝒖𝒓𝒔
𝒅𝒂𝒚 × 𝟎. 𝟗𝟓
= 𝟖, 𝟑𝟐𝟐 𝑮𝑾𝒉
Therefore, to meet the 2100 U.S. need for 42.9 million
GWh of sustainable electrical energy using only nuclear
power, 5,155 1-GW nuclear power plants will be needed.
𝟒𝟐,𝟗𝟎𝟎,𝟎𝟎𝟎 𝑮𝑾𝒉
𝟖, 𝟑𝟐𝟐 𝑮𝑾𝒉
𝒑𝒍𝒂𝒏𝒕 − 𝒚𝒆𝒂𝒓
= 𝟓, 𝟏𝟓𝟓
For comparison, the United States currently has only 99
operating commercial nuclear power plants with a total
nameplate power of about 100 GW. Their average capacity
factor is around 90 percent.
Nuclear fuel requirements
The primary fuel source for commercial nuclear fission
power plants is natural uranium. Natural uranium contains
the U235 isotope that can undergo fission yielding nuclear
energy. In 2016, the World Nuclear Association estimated
that a metric tonne (2,205 lb) of natural uranium will
produce, on average, 44 GWh in nuclear power plants. Thus, a
plant-year of operation yielding 8,322 GWh requires 189
metric tonnes of natural uranium.
𝟖, 𝟑𝟐𝟐 𝑮𝑾𝒉
𝟒𝟒 𝑮𝑾𝒉
=𝟏𝟖𝟗. 𝟏 𝒕𝒐𝒏𝒏𝒆𝒔
To steadily build up to the 5,155 1-GW nuclear power
plants needed by 2100, the United States will need about 36.6
million metric tonnes of natural uranium through 2100 with
more natural uranium needed after that.
The U.S. Energy Information Administration reports that
the United States has only about 2.5 million metric tonnes of
natural uranium even when speculative resources are
included. This is far short of what would be needed. In fact,
even with the speculative resources, the United States
natural uranium resources would meet the 120-year
lifetime needs of only about 110 1-GW plants. This would
enable current aging nuclear power plants to be replaced but
would be insufficient to enable any substantial expansion of
nuclear power. One solution to the shortfall of natural
uranium is to artificially breed another fissionable fuel. There
are two possible artificial fuels: plutonium and the U233
Fuel breeding and proliferation
Natural uranium contains only 0.72 percent of U235. Thus,
the 189 metric tonnes of natural uranium needed per plant-
year contains only 1.36 metric tonnes of U235. Replacing this
U235 with plutonium and/or U233 created using nuclear fuel
breeding is an option. To meet the needs of 5,155 nuclear
power plants in 2100, this would require breeding around
7,000 metric tonnes per year.
𝟏. 𝟑𝟔 𝒕𝒐𝒏𝒏𝒆𝒔
𝒚𝒓 × 𝟓, 𝟏𝟓𝟓 𝒑𝒍𝒂𝒏𝒕𝒔 = 𝟕,𝟎𝟏𝟏 𝒕𝒐𝒏𝒏𝒆𝒔
James Michael Snead, PE
Like U235, plutonium and U233 can be used to build nuclear
weapons. The United States used plutonium for one of its first
two weapons. The United States has also bred U233 and
demonstrated the ability to use this for a nuclear weapon.
(See Figure 10.) Thus, should the United States pursue nuclear
fuel breeding, many other nations would likely follow. The
option of breeding fuel to expand the use of nuclear power
likely increases the threat of nuclear weapons proliferation by
rogue nations.
Figure 10: United States nuclear weapon test using a
U233/plutonium core, April 15, 1955. (Credit: National
Nuclear Security Administration, Nevada Site Office,
Wikimedia Commons, public domain.)
Note: Advocates for U233 breeding from thorium argue
that proliferation-resistant reactors can be designed
and that bred U233 is not practical to use in a nuclear
weapon. On April 15, 1955, the United States exploded
a nuclear weapon using a U233/plutonium core
demonstrating that such assurances may be
inadequate for preventing a rogue nation from
obtaining nuclear weapons by secretively obtaining
Other considerations
In addition to the supply of fuel, long-term hazardous
waste disposal, plant security, cooling water availability, and
plant siting for thousands of nuclear fission power plants are
additional considerations impacting the practicality of the
large-scale use of terrestrial nuclear fission. When combined
with the limited supply of natural uranium and the
proliferation risk inherent with fuel breeding, a large-
scale expansion of fission nuclear power is not a
desirable solution to provide sustainable energy to
replace fossil fuels.
The key takeaway point from this assessment of nuclear
power is that, by 2100, the United States will require on the
order of 5,000 GW of continuous electrical power generation
capacity to meet its sustainable energy needs.
Fusion nuclear power
While nuclear fission involves a fissionable isotope, such
as U235, breaking apart and releasing energy in the process,
nuclear fusion involves forcing the nuclei of two or more
suitable isotopes sufficiently close together so that they will
fuse into a different element. As this happens, some of the
original mass becomes excess and spontaneously converts
into energy. This process happens naturally within a star
where the star’s intense gravity and internal pressure and
temperature force the nuclei together. Thus, sunlight is
energy released through natural solar fusion.
Other than within a star, achieving nuclear fusion requires
substantial input energy to force the target nuclei together
James Michael Snead, PE
sufficiently to fuse. In the early years of the nuclear age,
nuclear physicists determined how to use a nuclear fission
warhead’s explosion, such as seen in Figure 10, to trigger a
fusion explosion. Since that time, nuclear physicists and
engineers have been working to invent a nuclear fusion
reactor that, like its nuclear fission sister, would continuously
generate electrical power. While achieving nuclear fusion in a
laboratory has turned out to not be difficulthigh school
students often build small desktop fusion devices for science
showsproducing useful net electrical power has not been
Multiple approaches are being pursued for commercial
nuclear fusion. Like a fission reactor, all would likely be
thermal power plants where, unfortunately, as much as 70
percent of the fusion energy would become unavoidable
waste heat released at the power plant. Such fusion plants
would need, like fission power plants, sufficient cooling
water, locations not subject to earthquakes or floods, and
locations where significant waste heat could be safely
discharged into the local environment. Further, the likely
near-term fusion solutions would produce substantial
neutron radiation within the reactor meaning that dangerous
nuclear waste would still be produced and the potential for
breeding weapons-grade fission isotopes would exist. Thus,
while nuclear fusion may not have the limitations on fuel that
exist for U235-fueled fission plants, many of the other
drawbacks would remain. This will likely prevent GW-scale
fusion power plants from replacing fossil fuels for the United
States or most of the rest of the world for many of the same
reasons that scaling up nuclear fission is not feasible.
Eventually, a practical fusion power plant will likely be
small, producing hundreds of kilowatts or a few megawatts of
power and be air cooled. It would be used to produce
distributed electrical power for homes and businesses and
power electrical vehicles. A well-known science fiction movie
depicted such a fusion power plant in a car converted into a
time machine. Until such a fusion breakthrough is achieved,
engineers aiming to replace fossil fuels must focus on what
can be done with the science in hand.
James Michael Snead, PE
C. Wind power
Figure 11: School bus next to a wind turbine with a 79-
m hub height. Most wind turbines would have hub
heights of 110-140 m with 100+ m diameter rotors.
(Credit: J. M. Snead.)
Contiguous United States wind power potential
Wind power is generally the favored form of renewable
energy. (See Figure 11.) Wind power has been thoroughly
researched by the National Renewable Energy Laboratory
(NREL) to assess the commercial potential across the
contiguous United States. The NREL has estimated how many
GWh of variable wind-generated electricity commercial wind
farms could produce in the United States.
Figure 12: Map of possible commercial wind farm
locations. The commercial wind farm potential is based
on a hub height of 140 m (459 ft) where the gross
capacity factor is estimated to be 35 percent or
greaterthe minimum value with commercial
potential. A blue color indicates some viable
commercial wind farm locations may exist within each
20-km by 20-km square. The darker blue shades
indicate a higher percentage of the land in each square
has commercial potential. (Map source: National
Renewable Energy Laboratory for the U.S. Department
of Energy, no known restrictions on publication.)
James Michael Snead, PE
Across the contiguous United States, each 20 kilometer
(km) by 20 km area had the wind power potential assessed
for commercial wind farms using wind turbines with hub
heights of 80, 110, and 140 meters (m). The map in Figure 12
shows the possible commercial wind farm locations when
using turbines with a 140-m (459 ft) hub height. The results
of the assessment are summarized in Table 4.
Table 4: Results of the National Renewable Energy
Laboratory’s analysis of the contiguous United States
wind power potential with a gross capacity factor of 35
percent or greater for available land after exclusions.
Table 4 notes:
* Nameplate power is the maximum electrical power
output of the turbine’s generator.
Due to the wake turbulence created by the spinning
rotor’s blades, the turbines are assumed to be evenly
spaced a set distance apart, based on the diameter of
the rotors, when assessing the annual wind-electricity
potential of large wind farms. Testing has shown that a
spacing of 8 rotor diameters is about optimum. Thus,
the wind power potential shown in the above table
reflects this spacing.
As shown in Table 4, three turbine sizes were evaluated.
These turbines are assumed to be located in a square grid. The
amount of annual wind power available, per turbine,
generally increases as the turbine height and the rotor
diameter increase. However, with the increasing rotor
diameter, the spacing between the turbines also increases,
meaning that fewer turbines are installed per square
kilometer. For this reason, the total installed nameplate
power per square kilometer is different for each size turbine.
When using only a single size turbine, the maximum total
nameplate power would be installed by using 1.6 megawatt
(MW) turbines with 110-m hub heights and 100-m rotor
diameters. These wind farms would cover 3.4 million square
kilometers of the contiguous United States. The total installed
nameplate power would be 8,654 GW (highlighted in yellow
in Table 4).
From Table 4, the taller 140-m turbines could be installed
on a larger total area of 4.6 million square kilometers. This is
1.2 million square kilometers more than using only the 110-
m turbines. However, despite the larger area, the total
installed nameplate power would be less, due to the increased
turbine spacing.
To maximize the wind power potential for the entire
contiguous United States, 140-m turbines could be placed on
this additional 1.2 million square kilometers. This addition
would increase the total area of wind farms to 4.6 million
square kilometers with an installed nameplate power of
about 10,865 GW. The darker blue areas in the Figure 12 map
illustrate roughly how much of the contiguous United States
would be used to build 4.6 million square kilometers (1.8
million square miles) of wind farms.
James Michael Snead, PE
Using the Table 4 data, the total number of turbines
needed can be estimated. A combined total of about 6.6
million 110-m and 140-m turbines would be installed.
Covering 56 percent of the contiguous United States, virtually
all of the land on which people live would be used for wind
farms. To help visualize what much of the United States would
look like, four of the 110-m turbines would be installed per
square mile meaning that many Americans would live within
a half-mile of a large wind turbine.
Wind-power generation estimate
Today, most of the electricity generated comes from
generators driven by thermal energy produced by nuclear
energy, coal, or natural gas. These generators are turned on
(dispatched) when the utility requires additional electricity to
supply its customers. When turned on, these generators
produce their nameplate power. If a generator operates
continuously for the entire year, the capacity factor would be
100 percent. As mentioned earlier, a new 1-GW nuclear
power plant is assumed to have a 95 percent capacity factor.
It would be shut down for about three weeks a year for
refueling and maintenance. At all other times, it would be
generating its nameplate powerusually around 1 GW.
Wind turbines do not operate in this manner because the
wind speed varies continuously. Even when the turbine is
capable of generating power, it may be stopped because the
wind speed is too low or too high. The rest of the time, even
though the rotor is spinning, the actual power generated
varies depending on the wind’s speed.
For wind turbines, the capacity factor indicates the
percentage of the ideal total annual electrical energy actually
generated, on average, taking this variability into account. For
example, wind turbines located at the best land locations have
a gross capacity factor of about 50 percent. This means that
they will generate, on average, about 50 percent of the
electrical energy that would be produced if the turbines
generated their nameplate power continuously.
For commercial wind farms using the 110- and 140-m
turbines, an average gross capacity factor of 40 percent is
assumed for this analysis. NREL assumes a 15 percent
reduction for operational losses, yielding a net capacity factor
of 40 × 0.85 = 34 percent. (This compares to the recent actual
overall U.S. wind farm capacity factor of 32 percent.)
Returning to the estimate using 6.6 million wind turbines,
with an installed nameplate generation capacity of 10,865
GW, a 34 percent net capacity factor yields an annual average
electrical energy production of 32.4 million GWh. (Of course,
this will vary from year-to-year.)
𝟏𝟎,𝟖𝟔𝟓 𝑮𝑾 ×𝟑𝟔𝟓 𝒅𝒂𝒚𝒔
𝒚𝒆𝒂𝒓 ×𝟐𝟒 𝒉𝒐𝒖𝒓𝒔
𝒅𝒂𝒚 × 𝟎. 𝟑𝟒
=𝟑𝟐,𝟑𝟔𝟎,𝟑𝟏𝟔 𝑮𝑾𝒉
When using only dispatchable electrical power
generation, such as nuclear power, the total 2100 U.S.
electrical energy need would be met by generating 42.9
million GWh. When using only variable wind-generated
electrical energy instead, the variability increases the needed
total value by about 13 percent to 49.5 million GWh. (See
Appendix C.) For 6.6 million turbines covering 56 percent
of the contiguous United States, wind power could supply,
on average, only 65 percent of the total energy needed in
Note: The reliable functioning of America’s power grid
requires dispatchable electricity. A dispatchable power
source is one that the utility can turn on when needed.
The variability of wind-generated electricity generally
prevents wind farms from serving as a dispatchable
power source. Thus, for this analysis, all wind-
electricity is assumed to be used to produce hydrogen.
James Michael Snead, PE
This hydrogen will then be distributed through a
national pipeline network just as natural gas is today.
Local utilities will use this hydrogen to power gas
turbine generators to dispatch electricity to their
customers as needed. Local utilities would also
distribute the hydrogen to customers using it as a fuel.
This approach for addressing the variability of wind-
generated electricity increases the total wind-
electricity needed from 42.9 to 49.5 million GWh to
meet the U.S. total 2100 energy need. The wind’s
variability requires a 15.4 percent increase.
Recall that, in 2100, the per capita need for electrical
energy is 85,806 kWh of continuous electrical energy. If this
is provided exclusively by wind-electricity, the total needed
increases to 99,020 kWh. Noting that 1 MW = 1000 kW, a 1.6-
MW wind turbine has a nameplate generation capacity of
1,600 kW. With a 34 percent capacity factor, such a turbine
would annually produce, on average, 4,765,440 kWh. On
average, each wind turbine would supply the annual total
energy needs of only about 50 Americans in 2100.
𝟒, 𝟕𝟔𝟓,𝟒𝟒𝟎 𝒌𝑾𝒉
𝒑𝒆𝒓 𝒕𝒖𝒓𝒃𝒊𝒏𝒆
𝟗𝟗,𝟎𝟐𝟎 𝒌𝑾𝒉
𝒑𝒆𝒓 𝒄𝒂𝒑𝒊𝒕𝒂
=𝟒𝟖. 𝟏
Wind power impracticality
While individual wind turbines appear majestic, building
a national wind turbine forest of nearly seven million wind
turbines raises practicality issues such as the following:
1. The turbine blade tips will reach over 200 m high (663 ft).
As the rotors are turning much of the time, this will
significantly impact aviation, particularly general aviation.
Figure 13: Tornado damaged wind turbine. (Credit:
National Weather Service Wichita, National Oceanic
and Atmospheric Administration, used with
2. The 6.6 million turbines will have nearly 20 million of the
50-m long blades. Based on a reported blade failure rate of
0.54 percent per year, perhaps on the order of 100,000 blade
failures per year may be expected. (6) Blade failures can
include broken pieces being thrown from the rotor. (See
Figure 13.) In addition to blade failures, turbines also suffer
from fires, lightning strikes, being blown over during extreme
weather conditions, and throwing accumulated ice from the
blades during cold weather conditions. Such considerations
require a safe setback of the turbines from the public. Much of
America could become hazardous due to the extensive land
area required for wind farms.
James Michael Snead, PE
Figure 14: Construction of the base of a smaller wind
turbine. Taller and larger turbines would require
larger bases. Roughly 6.6 million bases would need to
be built and periodically replaced. (Credit: Tjadgen
Farms, National Renewable Energy Laboratory for the
U.S. Department of Energy, used as permitted.)
3. Each wind turbine requires installing a large concrete and
steel structure underground to provide a foundation for the
tower. (See Figure 14.) Modest size turbines require bases
using 24 tons of steel and several hundred cubic yards of
concrete. The larger turbines used in this estimate will
require correspondingly larger bases.
4. Operating wind turbines have distinct moving shadows
called flickerand sound signatures that are often disruptive
to humans and animals, especially in rural areas. Operating
turbines will also impact insects and birds, especially raptors.
5. The installation and maintenance of the wind turbines
impacts agricultural land fertility due to excavation, soil
compaction, and evaporation.
6. Wind turbines may impact the operation of radars used for
air traffic control and national security.
7. Offshore wind farms could impact shipping and, if visible
from the shore, disrupt the visual harmony of the seashore
that Americans value.
For reasons such as these, the mass deployment of wind
power to replace fossil fuels for the United States will likely
be politically unacceptable in nearly all inhabited parts of the
D. Ground solar power
The contiguous United States has substantial gross ground
solar power potential. Unfortunately, the day-night solar
cycle, weather-related insolation variability, existing land use
especially for agriculture, and terrain are significant factors
limiting the exploitation of this potential. Taking these
considerations into account, the commercial solar-electricity
potential of the United States can be estimated.
James Michael Snead, PE
Ground solar farm land area required
Figure 15: Solar farm using 1-axis tilting photovoltaic
panels. This farm is located at the Denver International
Airport. Note that the ground is cleared and leveled and
that the arrays do not completely cover the ground.
(Credit: National Renewable Energy Laboratory for the
U.S. Department of Energy, used as permitted.)
Like wind farms, ground solar farms are a popular form of
renewable energy production. Commercial solar farms have
been built across the country, especially in the western states.
(See Figure 15.)
Table 5: Summary of total land-use requirements for
photovoltaic and concentrating solar farms. (Source:
NREL/TP-6A20-56290, Table 9.) (7)
The solar power potential of the contiguous United States
has been extensively evaluated by the NREL. Table 5 is taken
from an NREL report summarizing data collected for existing
solar farms. The total installed nameplate power generation
capacity in the United States, at the time of the report, was
about 12 GW. The average capacity factor for these solar
farms was 20.77 percent. For the farms using fixed
photovoltaic arrays, highlighted in Table 5, the average
installed nameplate power was 33 MW (AC) per square
kilometer or 85.5 MW (AC) per square mile of the land area
within the farm’s perimeter fence.
Note: Unlike wind turbines which generate alternating
current (AC) electrical power, photovoltaic solar
panels produce direct current (DC) electricity. To
transmit this electricity from the farm, it must first be
converted into AC power. During this conversion, a
portion of the total DC power produced is lost as waste
heat. Thus, the proper output value to discuss for
photovoltaic solar is the final AC value.
James Michael Snead, PE
As with wind power, the variability of ground solar power
increases the required electrical energy to meet the total U.S.
2100 need from 42.9 to 49.5 million GWh. With a 100 percent
capacity factor, this would require 5,651 GW of nameplate
power generation capacity. With only a 20.77 percent
capacity factor, the required installed nameplate power is
about 27,208 GW.
𝟒𝟗. 𝟓 𝒎𝒊𝒍𝒍𝒊𝒐𝒏 𝑮𝑾𝒉
𝟑𝟔𝟓 𝒅𝒂𝒚𝒔
𝒚𝒆𝒂𝒓 ×𝟐𝟒 𝒉𝒐𝒖𝒓𝒔
= 𝟓, 𝟔𝟓𝟏 𝑮𝑾
𝟓, 𝟔𝟓𝟏 𝑮𝑾
𝟎. 𝟐𝟎𝟕𝟕 =𝟐𝟕,𝟐𝟎𝟖 𝑮𝑾
The corresponding required solar farm land area to meet
100 percent of the 2100 energy need would be 824,470
square kilometers (318,330 square miles).
𝟐𝟕,𝟐𝟎𝟖 𝑮𝑾 ×𝟏𝟎𝟎𝟎 𝑴𝑾
𝟑𝟑 𝑴𝑾
𝒔𝒒 𝒌𝒎
=𝟖𝟐𝟒,𝟒𝟕𝟎 𝒔𝒒 𝒌𝒎
On average, each American in 2100 would need 1,649
square meters (0.4 acre) of solar farm to supply their total
annual energy need.
𝟖𝟐𝟒,𝟒𝟕𝟎 𝒔𝒒 𝒌𝒎 × 𝟏, 𝟎𝟎𝟎,𝟎𝟎𝟎 𝒔𝒒 𝒎
𝒔𝒒 𝒌𝒎
𝟓𝟎𝟎 𝒎𝒊𝒍𝒍𝒊𝒐𝒏 = 𝟏, 𝟔𝟒𝟗 𝒔𝒒 𝒎
Solar farm placement
Figure 16: The top map shows the solar photovoltaic
energy potentialannual average watts per square
meter per dayfor a flat solar array oriented south,
tilted to the location’s latitude from the vertical. The
bottom map is the top image overlaid on a relief map of
the terrain. (Solar map created by the National
Renewable Energy Laboratory for the U.S. Department
James Michael Snead, PE
of Energy, used as permitted. Relief map credit: U.S.
Geological Survey, no known restrictions. Bottom
composite map credit: J. M. Snead.)
As shown in the upper map in Figure 16, the American
Southwest has the highest total ground solar insolation and is
the best location in the contiguous United States for
commercial solar farms. However, when this map is overlaid
on a terrain map, as shown in the bottom map in Figure 16,
terrain significantly limits the land area suitable for
commercial ground solar farms. The reason for this is that,
generally, for commercial solar farms only flat land at least a
square kilometer in size with an overall grade of 1 percent or
less is suitable.
Ground solar power estimate
The seven southwestern states of Arizona, California,
Colorado, Nevada, New Mexico, Texas, and Utah have the
greatest ground solar potential. The total area of these states
is about 2.5 million square kilometers (about 968,000 square
miles). The NREL assessed the land suitable and available for
locating commercial solar photovoltaic farms in these states.
The results are shown in Table 6.
The total suitable land in these seven states is about
225,929 square kilometers (87,231 square miles)only
about 9 percent of the total land area. The total possible
installed nameplate power would be 7,548 GW while the total
possible available solar-electricity generated annually would
be, on average, 13,589,529 GWhabout 27 percent of the U.S.
2100 total energy need.
Table 6: Results of an NREL study of the solar
photovoltaic potential in the southwestern United
States where the land slope is less than 1 percent.
(Land area data source: National Renewable Energy
Laboratory.) (8)
To increase the supply of solar-electricity, additional land
could be graded flat in the Southwest and solar farms could
be built on agricultural and graded undeveloped land in the
Southern states. Both options are unlikely to be generally
accepted by the public.
James Michael Snead, PE
E. Combined terrestrial solution using
primarily wind and ground solar
Figure 17: Wind farm in Washington. These wind
turbines are closely spaced in rows to handle
prevailing winds primarily from one direction. These
turbines have a hub height of only about 60 m
compared to turbines with hub heights up to 140 m
used in this analysis. (Credit: Mike McPheeters,
National Renewable Energy Laboratory for the U.S.
Department of Energy, used as permitted.)
Combining wind and ground solar power could enable the
United States to meet the projected 2100 energy needs using
only terrestrial sustainable energy. The maximum buildout of
wind power would provide 32.3 million GWh. (See Figure 17.)
Solar farms in the seven southwestern states would provide
an additional 13.6 million GWh. Together, wind and ground
solar power would provide 45.6 million GWh or 93 percent of
the needed total. Additional solar farms along with nuclear,
geothermal-electricity, hydroelectricity, and biomass could
make up the shortfall. This solution would, however, entail
building 4.6 million square kilometers of wind farms and
about 225,000 square kilometers of solar farms covering
nearly 60 percent of the contiguous United States. (See
Figure 18.)
Figure 18: A combined wind and ground solar solution
would require building about 4.6 million square
kilometers of wind farms on all of the darker blue areas
shown on the map along with about 225,000 square
kilometers of ground solar farms in the Southwest.
(Map source: National Renewable Energy Laboratory
for the U.S. Department of Energy, no known
restrictions. Credit: J. M. Snead.)
While the United States could adopt a wind and ground
solar power solution for transitioning from fossil fuels, the
extent of the needed wind and ground solar farms has not
been explained to the public. To pursue this solution, it is
likely that the appearance of the Southwestconsidered by
many to be a national treasurewould be markedly altered
with all suitable flat land needing to be cleared and leveled.
The central United States, between the Rocky Mountains and
the Alleghany Mountains, would be used to build horizon-to-
James Michael Snead, PE
horizon wind farms. About every one-half mile, a large 110-
140 m hub height turbine would be installed, each requiring
a substantial buried concrete base. Extensive additional
overhead electrical power transmission systems would need
to be built to collect and distribute the solar- and wind-
generated electricity.
It is unlikely that blanketing the contiguous United States
with nearly 5 million square kilometers (nearly 2 million
square miles) of wind and solar farms will be politically
acceptable as this may require the government’s extensive
use of eminent domain to obtain needed land, the imposition
of mandatory restrictions on private land use, forced rural
home relocation for safe separation, restrictions on general
aviation, etc. A different, less intrusive solution is needed.
Hence, with terrestrial renewable energy and nuclear
solutions not providing a practical means to replace fossil
fuels, we need to turn to space-based sustainable energy.
Chapter V: GEO Space Solar
Figure 19: The right side of the split image is the
famous Apollo 8 photograph of the Earth as seen from
lunar orbit taken on December 24, 1968. The left side
of the image is reversed in color to highlight that the
space surrounding the Earth is filled with sunlight
renewable powerthat is invisible to the human eye.
(Original photograph credit: William Anders, NASA.
Credit: J. M. Snead.)
With no practical terrestrial sustainable-energy solutions
to replace fossil fuels, the United States must turn to the only
remaining source of sufficient renewable energysunlight in
outer space. As illustrated in Figure 19, while space appears
to be empty, the space surrounding the Earth is actually filled
with intense sunlightspace solar power freely available to
be used.
James Michael Snead, PE
Utilizing space solar power will be a macro-
engineering project of immense scale. A century ago,
American engineers faced and overcame comparable
challenges with building large hydroelectric dams, such as the
Hoover Dam, on a scale that had never been attempted.
A. Building the Hoover Dam
The United States is blessed with many large rivers that
have been tamed to control flooding, generate electricity, and
enhance the economic prosperity of America. As settlement
expanded in the western states in the late 1800s, building
dams to control flooding and provide irrigation water in the
arid parts of these states became a matter of national interest.
The Colorado River was first used to supply irrigation water
in the 1890s. In 1902, the growing city of Los Angeles
investigated building a small 12-m hydroelectric dam. Finally,
in 1922, the federal Bureau of Reclamation recommended
building a dam in Black Canyon, several miles downriver of
the original location of interest in Boulder Canyon. Congress
finally approved a bill authorizing the Federal Government to
undertake the construction of Boulder Damlater renamed
Hoover Damin 1928. The Bureau of Reclamation designed
the dam, adding electricity generation only near the end of the
design process. (See Figure 20.) Construction of the diversion
tunnels began in 1931 with Lake Mead beginning to fill on
February 1, 1935. Electricity was first generated in March
Figure 20: Engineering description of the Hoover Dam
(top). Black Canyon before construction (lower left).
Hoover Dam (lower right). (Drawing credits: U.S.
Government, Wikimedia Commons, public domain.
Black Canyon photograph credit: W. T. Lee, USGS,
Wikimedia Commons, public domain. Hoover Dam
photograph: Ansel Adams, National Archives,
unrestricted use.)
Black Canyon was a remote and extremely hostile location
in the early 1900s. Summer temperatures in 1931 rose to 120
°F. Temperatures in the diversion tunnels hit 140 °F. There
was no air conditioning. To house the engineering and
construction workers, a model city was built near the
James Michael Snead, PE
construction site—today’s Boulder City. Nearby Las Vegas
had only 5,000 residents when the project began. Building the
Hoover Dam was a major American engineering
accomplishment of the 20th century. Today, Hoover Dam can
generate slightly more than 2 GW.
B. United States’ 2100 space solar power
As noted in the discussion of nuclear power, by 2100, the
United States will need around 5,155 GW of electrical
generation capacity (assuming a 95 percent capacity factor).
While it is reasonable to assume that terrestrial sustainable
energy sourcesnuclear, wind, ground solar, etc.will
continue to provide about 20 percent of this need, GEO space
solar power will need to provide the balance of about 4,124
GW. To put this starkly into perspective, the United States
will need to construct a total generating capacity
equivalent to about 2,000 Hoover Dams in geostationary
Earth orbit by 2100. To undertake this, America must
pursue a spacefaring industrial revolution that will enable
this vital, war-avoiding project to succeed.
C. GEO space solar power
Figure 21: 1970s NASA baseline 5-GW GEO space solar
power concept. (Reference: NASA Technical
Memorandum 58232, Satellite Power System Concept
Development and Evaluation Program, Volume I,
Technical Assessment Summary Report, Fig. VII-4,
November 1980.)
While the idea of tapping space-based sustainable energy
first arose from Konstantin Eduardovich Tsiolkovsky in 1926,
the technical approach to accomplish this was first defined by
Peter Glaser in 1968, followed by his patent in 1973. Glaser
proposed building large platforms in GEO that would convert
sunlight into electrical power. This power would then be
transmitted to the ground where it would be converted into
AC electrical power, providing utilities with a nearly
continuous supply of electricity. (See Figure 21.)
James Michael Snead, PE
Beginning in the late 1970s, the National Aeronautics and
Space Administration (NASA), the U.S. Department of Energy,
and industry began a lengthy series of studies of GEO space
solar power. A baseline design emerged that would deliver 5
GWequal to 2.5 Hoover Damsof nearly continuous
electrical power from the ground receiving antenna array,
referred to here as an astroelectric plant.
Note: At local midnight near the spring and fall
equinoxes, a GEO space solar power platform will enter
the Earth’s shadow and temporarily stop collecting
sunlight. This lasts for about one hour. Backup gas-
turbine generators at the utilities will provide
electricity during this period. The total period of outage
will be about 5 percent of the year, yielding a capacity
factor of about 95 percent compared to 21 percent for
ground solar farms.
Figure 22, using a later NASA GEO space solar power
design, illustrates how such a platform would work. Sunlight
is “captured” by mirrors that reflect the sunlight onto
photovoltaic solar arrays. Converted into electrical power, the
solar-electricity is then transmitted to the ground receiver.
Roughly 26 GW of raw sunlight yields 6.5 GW of baseload
electrical power transmitted to the ground astroelectric
plant. Each astroelectric plant then outputs 5 GW of electrical
power to supply local utilities and produce hydrogen. For
these calculations, the end-to-end efficiency is estimated to be
slightly under 20 percent.
Figure 22: With an input of 25.9 GW of sunlight, the
GEO space solar power system will provide 5 GW of net
baseload electrical power from the astroelectric plant
to local consumers. (Original GEO space solar power
illustration source: NASA. Modified image credit: J. M.
Recall that, by 2100, the per capita need for baseload
electrical power is about 10 kW. Thus, each 5-GW
astroelectric plant would meet the needs of 500,000
Americans in 2100. As shown in Figure 22, about 38 square
meters of sunlight is all that would need to be captured to
provide 10 kW per person. This is only about the floor
area of a two-car garage!
𝟏𝟗. 𝟐 𝒔𝒒 𝒌𝒎 × 𝟏,𝟎𝟎𝟎,𝟎𝟎𝟎 𝒔𝒒 𝒎
𝒔𝒒 𝒌𝒎
𝟓𝟎𝟎,𝟎𝟎𝟎 𝑨𝒎𝒆𝒓𝒊𝒄𝒂𝒏𝒔 =𝟑𝟖. 𝟒 𝒔𝒒 𝒎
D. Astroelectric plant land requirements
The transmitted power is received at a special ground
receiving array referred to as an astroelectric plant. The
baseline astroelectric plant size is shown in Figure 23.
James Michael Snead, PE
Figure 23: GEO space solar power ground receiving
stationastroelectric plantconfigured for a location
at 35° latitude when using the 2.45 GHz transmission
frequency and a 1-km transmitter diameter. (Credit: J.
M. Snead.)
The receiving array is similar to a solar array except that
the array panels contain small dipole antennas rather than
photovoltaic cells. Each receiving array covers 104 square
kilometers of land (40 square miles). With the outer safety
zone, each astroelectric plant will require about 164 square
kilometers (63 square miles).
To provide the energy required to replace fossil fuels in
2100, about 825 astroelectric plants will be required,
covering about 135,000 square kilometers (52,000 square
miles)less than 2 percent of the contiguous United States.
This compares very favorably with the nearly 5 million square
kilometers (2 million square miles) required for the
combined wind and ground solar solution.
Also shown in Figure 23 is the power intensity of the
transmission beam expressed in watts per square meter. By
design, the peak power at the center of the beam is limited to
about one-quarter of the noon insolation at the equator
about 230 watts per square meter. (Noon insolation at the
equator is about 1000 watts per square meter.) For
comparison, the power level in a countertop microwave oven
is about 9000 watts per square meter. Therefore, the peak
power level in the transmission is less than 3 percent of the
power level in a kitchen microwave oven.
The power level in the beam falls off towards the edge of
the receiving array. At the edge of the receiving array, the
power is only 1 percent of the noon insolation. At the edge of
the safety zonethe closest public access pointit is two
orders of magnitude less. This is also two orders of magnitude
less than the permitted exposure level per federal guidelines.
The large size of the receiving antenna is used to keep the
power levels low.
E. Astroelectric plant locations
To complete the transition from fossil fuels, 825
astroelectric plants must be built within the contiguous
United States. As part of earlier studies, possible locations
within the contiguous United States were examined. The
contiguous United States has a land area of 7,663,942 square
kilometers. This was divided into square cells measuring 26
km on a side, yielding 11,337 cells. (See Figure 24.)
James Michael Snead, PE
Figure 24: Summary Map 8 showing excluded cells
(dark) and non-excluded cells (white). Excluded cells
include: national recreation areas, population areas,
unacceptable topography, navigable waterways,
marshlands, wetlands, national forests, Indian
reservations, endangered species habitats, interstate
highways, and land in cultivation. (Reference: U.S.
Department of Energy, Report: HCP/R-4024-10,
Satellite Power System (SPS) Mapping of Exclusion
Areas for Rectenna Sites, October 1978, Fig. 33.)
Each cell has sufficient area for 1.5 astroelectric plants.
Thus, about 550 cells would be needed. During the 1978
evaluation, cells were excluded due to unacceptable
topography, navigable waterways, national recreation areas,
population areas, marshlands, wetlands, national forests,
Indian reservations, endangered species habitats, interstate
highways, and land in cultivation. Of the total, 3,203 cells
remained which should meet the needs of the 550 cells
required to build 825 astroelectric plants.
With sufficient land being available, at 825 locations
across the country, the equivalent of 2.5 Hoover Dams
providing space-based sustainable electrical power would be
built enabling the United States to be energy secure with
sustainable energy. Each of these astroelectric plants
would meet the annual energy needs of 500,000
F. Comparison of GEO space solar power
with wind and ground solar
Figure 25: Comparison of the land area needed to
replace fossil fuels with wind and ground solar power
and the land area required for astroelectric plants. The
two circles represent the total land area required for
ground solar farms (left) and astroelectric plants
(right). Each circle’s size is scaled to the map of the
United States. (Map source: National Renewable
James Michael Snead, PE
Energy Laboratory for the U.S. Department of Energy,
no known restrictions. Credit: J. M. Snead.)
Figure 25 compares the land area required for wind and
ground solar power with the land area required for the
astroelectric plants needed to receive power from the 825
GEO space solar power platforms. In this figure, the two
circles represent the total land area required for ground solar
farms and astroelectric plants. Each circle’s size is scaled to
the map of the United States.
G. The world’s 2100 sustainable energy
The world must also transition from fossil fuels in an
orderly manner. Historically, per capita energy use in the
United States has been about twice that of Europe and Japan.
At this lower European/Japanese per capita energy
consumption rate, each 5-GW astroelectric plant would
meet the energy needs of about 1 million people. Using
this as a planning benchmark, 10,000 5-GW astroelectric
plants will be needed by 2100 to end energy
impoverishment and enable sustainable development for
the world’s projected 10 billion people. This is the scale of
the sustainable energy engineering challenge that must be
conquered if warfare is to be avoided and fossil fuel CO2
emissions ended.
Chapter VI: America’s Coming
Spacefaring Industrial
Figure 26: United States spaceship departing LEO
space dock. (Concept credit: J. M. Snead. Image credit:
U.S. Government, public domain.)
“To boldly go” has been an unofficial American
spacefaring motto since the 1960s, so far realized only in
science fiction. Now, America’s pursuit of vital GEO space
solar power will take Americans boldly throughout the
central solar system. While space explorers will lead the way,
a spacefaring industrial revolution will quickly follow,
establishing a permanent American presence. American
James Michael Snead, PE
aerospace professionals, this century, will turn America’s
long-held spacefaring dream into reality. (See Figure 26.)
A. The impending scale of necessary
human spacefaring operations
From what today is almost a standing start, America’s
human spacefaring operations will undergo a significant
expansion to undertake the unavoidable transition to space-
based sustainable energy. America will need to build as
many as 825 5-GW GEO space solar power platforms by
2100. Each of these platforms will mass on the order of
10,000-30,000 metric tonnes and will cover an area about the
size of Manhattan Island. Obviously, the existing approach
of assembling a satellite on the Earth and launching it into
GEO will not work. To make this happen, outer space will
need to be industrialized by Americans living and
working in space.
Low Earth orbit (LEO) will become the starting point for
building the enabling spacefaring logistics (astrologistics)
infrastructure. Space bases, habitats, and space docks, as
shown in Figure 27, will need to be built in LEO to provide a
destination for Earth-to-orbit transports, logistics services
such as housing and fueling, and a point of departure for
transportation beyond LEO. With strong federal leadership,
the first generation of these LEO astrologistics capabilities
can be operational within 10-15 years.
Figure 27: Space Launch System delivering a large
airlock to a LEO space base’s space dock. (Credit: U.S.
Government, public domain.)
As these permanent LEO facilities become operational,
they will be used to expand the permanent astrologistics
infrastructure outward to GEO, providing transport to and
from GEO and housing and work facilities in GEO. As the GEO
capabilities become operational, the construction and
evaluation of prototype GEO space solar power platforms will
be undertaken. This will be followed by the initial low-rate
construction of operational GEO space solar power platforms
along with their astroelectric plants within the United States.
Perhaps within two decades from todayaround 2040
the first astroelectricity will be beamed to the Earth and
fed into the U.S. electrical power grid. This will be a
milestone comparable to the first generation of
hydroelectricity by the Hoover Dam and the first generation
of nuclear-electricity.
James Michael Snead, PE
Figure 28: NASA visualization of the Space Launch
System launching an Orion spacecraft. (Credit: NASA.)
As Gerard K. O’Neill identified in the 1970s, it is not
feasible to build a large number of GEO space solar power
platforms using just terrestrial resources absent a dramatic
breakthrough in space propulsion. Lunar and asteroidal
resources will be needed. These resources must be located
and the means to extract, refine, and produce the components
needed to build the GEO space solar power platforms put in
place. Undertaken in parallel with the initial astrologistics
infrastructure construction, this will start with the extensive
robotic and human exploration of the Moon and the asteroids
using the human exploration systems now completing
development. (See Figure 28.)
To continue this exploration routinely and safely will
require expanding the astrologistics infrastructure beyond
GEO to lunar orbit, the lunar surface, and out into the asteroid
belt. Orbiting space bases, surface bases on the Moon, lunar
landers, space ferries, and spaceships capable of deep space
operations will be needed. Eventually, large-scale industrial
facilities will need to be builtprobably at the L4/L5 Earth-
Moon LaGrange pointsto process these mined
extraterrestrial resources into the products needed to build
most of the GEO platforms. (See Figure 29.)
Figure 29: Notional space colony at an Earth-Moon
LaGrange point used to build GEO space solar power
systems. (Credit: NASA.)
Obviously, to build perhaps as many as 10,000 platforms
by 2100, the scale of these spacefaring industrial operations
will rival large terrestrial industrial operations. Toward the
end of the century, one or two new GEO platforms and
their astroelectric plants will need to be brought online
daily. This means that hundreds of platforms will be under
construction at any time in the final decades of this century.
This could easily involve 100,000 people or more living
and working throughout the central solar system. With
many of these future American spacers being today’s children,
we can only imagine their exciting future. The doldrums of the
last few decades of America’s human space program will fade
quickly as America turns its attention to becoming a true
human spacefaring nation.
James Michael Snead, PE
Note: In 2017, the world produced 80 million
passenger cars. Daily, on average, over 300,000 metric
tonnes of automotive technology components were
produced. Two GEO space solar power systems
completing production daily would require, perhaps,
20,000-60,000 metric tonnes of comparable
technology components being produced dailymost
supplied using space mining, refining, and
B. The scale of space solar power
economic operations
A new 1-GW nuclear power plant now has a direct cost of
about $5 billion. At this cost per GW, the United States may be
expected to spend in the ballpark of, at least, $21 trillion to
convert to GEO space solar power. In making use of this new
sustainable energy, the world will spend many times this
amount, in the ballpark of $250 trillion.
Today, hydroelectricity has a cost of generation of about
$0.01 per kWh or $10,000 per GWh. (For comparison, the cost
of coal-generated electricity is about $0.04 per kWh.) Using
this hydroelectric cost as a benchmark, in a year’s time, a 5-
GW GEO space solar power system, with a 95 percent capacity
factor, would generate $416 million worth of electricity at
$0.01 per kWh. The 825 U.S. GEO space solar power systems
would produce about $343 billion worth of electricity
annually. Worldwide, the 10,000 systems would provide $4
trillion worth of electricity annually. Total annual commercial
revenues would, of course, be some multiple of this amount.
C. America’s spacefaring transformation
Undertaking GEO space solar power will require an
American aerospace enterprise involving government-only,
joint government-private, and purely private operations
similar to what happened with the opening of the jet age
beginning in the late 1940s. By mid-century, immense new
space power, space mining, space manufacturing, and
astrologistics industries will be created. In short, America will
be undertaking a spacefaring industrial revolution that will
transform America into a true commercial human spacefaring
This spacefaring industrial revolution will dwarf the
Apollo program. Generations of Americans will be involved in
GEO space solar power. Explorers will return to the Moon and
venture to the asteroids to explore for critically-needed
resources. Scientists will develop the methods needed to
process these resources into needed products. Engineers and
construction workers will design and build spacefaring
facilities and habitats in LEO, GEO, the LaGrange Points, and
on the Moon, and will design and build spaceships capable of
routinely traveling throughout the central solar system.
Today’s space capabilities will, in just a matter of years, be
considered antiquated!
James Michael Snead, PE
D. Is this spacefaring future realistic?
Figure 30: Wright Brother’s airplane at liftoff on the
first of four flights of their heavier-than-air aircraft,
December 17, 1903. Orville Wright is the pilot. Wilbur
Wright is at the wingtip. The final and longest flight
traveled 852 feet and lasted 59 seconds. A gust of wind
then caught the airplane, damaging it beyond repair. It
is displayed today in the National Air and Space
Museum, Washington, DC. (Credit: John T. Daniels,
Library of Congress, Wright Brothers collection, LC-
DIG-ppprs-00626, no known restriction on
Imagine time traveling back to the wind-swept sand dunes
on the Outer Banks of North Carolina on a cold December 17,
1903. The barren visage reminds you of photographs of the
Moon. In the distance, a few people are moving a fragile-
looking biplane into position. The brisk 27 mph wind makes
this difficult. You hear the engine start, see the propellers spin
up to speed, watch as the aircraft is pushed forward by its
propellers into the stiff wind. One man runs alongside,
holding the wingtip to keep the aircraft balanced on the sled
riding a wooden track until suddenly the aircraft lifts off,
flying alone. You are seeing history being made and a world
being changed as the dream of human flight is achieved. (See
Figure 30.)
Excited, you start to run down the hill, sliding in the sand
trying to keep your balance. As you run you think of what you
will say until, suddenly, you stumble to a stop, still a good
distance away. What, you realize, could you say about the
future of aviation that they would believe. The world of
commercial aviation that we take for granted would sound
fantastic to the world’s then foremost aeronautical engineers.
The flight you “witnessed” lasted only seconds and barely
traveled over a hundred feet. They had labored years to get to
this point. You intended to tell them of flying miles high in the
sky, eating lunch, and watching movies in an aircraft longer
than the distance they had just flown. Who, in 1903, would
believe such a fantastic tale? Yet, it is the truth!
James Michael Snead, PE
Figure 31: Composite radar image of the commercial
airliners flying above the contiguous United States on a
typical morning or afternoon. (Credit: Federal Aviation
Administration Air Traffic Control, no known
restriction on publication.)
As you read this, several thousand commercial airliners,
carrying perhaps a quarter million people, are flying above
the contiguous United States. (See Figure 31.) This has been
common since the 1960s—so common and safe that we don’t
give it a second thought.
Can the United States, this century, undertake a
transformation into a true commercial human spacefaring
nation to build the space-based sustainable energy systems it
will need to remain free and energy secure? Without a doubt!
And what an exciting future this will be for a nation that has
dreamed of becoming spacefaring since the 1950s.
America is finally ready to boldly go spaceward!
James Michael Snead, PE
Chapter VII: Renewing America
for the 22nd Century
Everything is theoretically impossible, until it is done.
Robert A. Heinlein
Undertaking GEO space solar power will enable America’s
engineers to eliminate America’s contribution to the CO2
environmental threat and ensure America’s sustainable
energy security. It may be expected that this 21st century
national spacefaring enterprise will expand to include
America’s friends, allies, and non-belligerent trading
partners. A century ago, building one Hoover Dam was an
engineering marvel. This century, American engineering will
lead the world in building the equivalent of 25,000 Hoover
Dams to enable sustainable development worldwide. As
amazing as this sounds, it will be just the beginning of a
century of engineering marvels.
While America undertakes a spacefaring engineering and
industrial revolution to develop extraterrestrial resources for
space-based sustainable energy and space settlement,
America will be undergoing a comparable revolution from a
non-sustainable to a sustainable culture. This will entail far
more than simply swapping out coal power plants for
astroelectric plants. The switch to space-based sustainable
power will trigger a sustainable engineering and industrial
revolution that will permeate virtually all of America. In the
process, most of today’s America will be deconstructed and
rebuilt enabling us to leave our children and
grandchildren a profoundly better 22nd century America
an America literally renewed from the ground up!
A. Modern America’s 19th and 20th century
Figure 32: Mulberry St., New York City, 1900. (Credit:
Detroit Publishing Co., Library of Congress, LC-USZC4-
1584, no known restrictions on publication.)
The 19th century’s steam-powered industrial revolution
created urban America as a place for millions of Americans to
escape the farm to live and work. (See Figure 32.) By the end
of that century, most of these urban areas were crowded and
unpleasant places to live, especially to raise a family. Urban
America became a place to escape from, especially as
industrialization enabled more convenient forms of travel.
James Michael Snead, PE
Figure 33: Children playing in Greendale, WI, 1939.
Greendale was one of three model towns built by the
Federal Government during the Dust Bowl years of the
Great Depression. (Credit: John Vachon, Library of
Congress, LC-USF33-T01-001431-M1, no known
After World War II, as the post-war baby boom took hold
and an improved standard of living enabled home and car
purchases, America modernized by building immense
suburbs following model communities built during the Great
Depression. (See Figure 33.) Crowded urban centers, with
tightly-packed blocks of stores and homes, were no place to
raise children. America moved out, building single-family
homes in quiet neighborhoods.
Figure 34: Abandoned home in Chicago, IL, 1974.
(Credit: Danny Lyon, National Archives, unrestricted
Nearly a century later, much of urban and suburban
America needs to be rebuilt. (See Figure 34.) From a form, fit,
and function perspective, most of America is outdated and
needs to be replaced. We certainly cannot leave this blighted
America to our children and grandchildren!
James Michael Snead, PE
B. Potable water’s metaphor for what is to
Figure 35: Potable water flowing from a faucet. (Credit:
U.S. Government work.)
Potable water is essential for life and cleanliness. (See
Figure 35.) Today, about 90 percent of Americans get their
life-critical potable water through public and private water
Without a second thought, we turn on a faucet and water
flows. Fortunately, only very rarely does it not.
Figure 36: Roman public toilet. (Credit: Wikimedia
Commons, public domain.)
Roman civilization was built on assured supplies of
potable water meeting the drinking, food preparation,
bathing, and sanitary needs of Romans. Multiple aqueducts
provided sufficient water supplies per capitacomparable to
that in modern citiesenabling Rome to grow to be the
world's first metropolis with over a million inhabitants able
to provide many trappings of modernity (e.g., public baths,
running water to many buildings, underground sewers,
theaters, stadiums, and permanently-constructed buildings of
stone, brick, and concrete.) (See Figure 36.)
James Michael Snead, PE
Figure 37: Roman aqueduct in Segovia, Spain. (Credit:
Library of Congress, LC-DIG-ppmsca-52830, no known
restrictions on publication.)
Rome is seen by many as the start of western civilization.
Roman colonies built aqueducts to supply the potable water
necessary for Roman culture to be transplanted to the
frontier. (See Figure 37.) Rome's aqueducts made potable
water a fixture of modern civilization. Today, the cost is so low
that, in America, having potable water is taken for granted.
America’s orderly transition to GEO space solar power will
remove today's fossil fuel insecurity just as Rome's first
aqueducts removed the insecurity of being dependent on
unhealthy waters from the Tiber River or nearby wells. Once
Rome was water secure, the means for its future substantial
growth was enabled. With this in mind, American engineers
should ponder the impact on America when sustainable
power becomes like potable watera reliable, low-cost
convenience to be broadly used.
C. From hydroelectricity to
Figure 38: Grand Coulee Dam, producing 6.8 GW, on the
Columbia River. (Credit: U.S. Government work.)
With the invention of electrical generation in the late
1800s, besides supplying potable and irrigation water, major
rivers were seen as a renewable energy source to power the
generators. The first hydroelectric plants were built in the
United States in the 1880s. These were quickly followed by
interest in exploiting the potential of the major western rivers
such as the Colorado and Columbia.
The Columbia River watershed covers most of the states
of Oregon and Washington. Sixty dams have been built in this
watershed, providing a nameplate generation capacity of 36
James Michael Snead, PE
GW. The Grand Coulee Dam is the largest with a nameplate
capacity of 6.8 GW. (See Figure 38.)
Low-cost, highly-reliable, sustainable astroelectricity will
transform the entire United States just as hydroelectricity did
for many of the western and southern states in the 1930s and
1940s. Sitting in GEO, the space solar power platforms will
collect sunlight and transmit this power to the astroelectric
plants. From there, the sustainable power will flow into
America’s power and fuels infrastructure, providing low-cost,
reliable power to rebuild America.
D. Transformative technologies
Five emerging technologies, when combined with space-
based sustainable power, will enable America’s renewal this
century. These are:
3D additive manufacturing
Robotic “lights-out” factories
Intelligent recycling
Construction humanoids
Intelligent deconstruction
3D additive manufacturing
Figure 39: 3D additive manufacturing. (Credit: U.S.
Government work.)
In the 1980s, printing technology significantly advanced
with the development of dot matrix printing. This technology
enabled the entire document/image preparation and printing
process to be performed digitally. While the first dot matrix
printers still relied upon the mechanical transfer of ink from
a ribbon to the paper, the technology quickly advanced to
incorporate small inkjets that would squirt a microscopic
blob of ink onto the paper. Mechanical printing soon became
obsolete. The addition of color further advanced the
technology to enable photographic images to be faithfully
James Michael Snead, PE
This inkjet technology has taken the next step, moving
from 2D to 3D with the ability to print a variety of materials,
layer upon layer, to create complex 3D shapes. Parts are
designed using computer-aided design software and printed
using 3D printers. (See Figure 39.)
Figure 40: Small building and vehicle mostly fabricated
using 3D additive manufacturing. (Credit: Oak Ridge
National Laboratory, U.S. government work.)
Figure 40 illustrates the range of objects that can, at least
in part, be fabricated using 3D additive manufacturing. The
film thrust bearing, shown in Figure 41, illustrates what the
combination of 3D additive manufacturing and ingenious
engineering can produce.
Figure 41: Complex thrust bearing fabricated using 3D
additive manufacturing. (Credit: Bugra Ertas, U.S.
Department of Energy, U.S. Government work.)
Software engineers use libraries of standard subroutines
to enable new smartphone applications to be developed
James Michael Snead, PE
quickly. 3D additive manufacturing will provide hardware
engineers with the physical equivalent of the software
development environment. Digital libraries of products will
be developed that hardware engineers will use to produce
parts for new products without having to order parts from
catalogs. Eventually, innovative engineering will enable most
commercial products to be produced locally using 3D additive
“Lights-out” robotic factories
Figure 42: Testbed used to develop highly-dexterous
robotic arms. (Credit: Falco, National Institute of
Standards and Technology, U.S. Government work.)
Factories in which robots alone perform the
manufacturing process, with only minimal human
involvement, are referred to as “lights-out” factories. (See
Figure 42.) These are not new. A Japanese company has been
building robots in this manner since the early 1990s. The
adoption of increasing levels of manufacturing automation to
reduce human labor has its roots during Roman times.
Figure 43: Electric sports car built mostly from parts,
including the body, fabricated using 3D additive
manufacturing. Note the surface finish on the car’s
body. (Credit: Charles Watkins, Oak Ridge National
Laboratory, U.S. Government work.)
With 3D additive manufacturing, a new repertoire of
manufacturing capabilities will be available to be exploited in
lights-out factories. The combination of subtractive (e.g.,
drilling a hole) and additive manufacturing will enable most
consumer products to be produced on demand using digital
product databases. (See Figure 43.) These factories will also,
of course, produce new and better versions of themselves,
enabling entire manufacturing centers to be built once a
“seed” factory is shipped in and assembled.
The only inputs will be materials and energy. With the use
of recycled materials and space-based sustainable power, the
economic cost of product manufacturing, in terms of the
James Michael Snead, PE
required human involvement, will shrink. This means that the
replacement of outdated or out-of-fashion consumer
productsincluding homes and buildingswill not be
primarily an economic decision, but a personal choice done
without any moral conflict.
Intelligent recycling
Figure 44: Stack of crushed cars awaiting recycling.
(Credit: IFCAR, Wikimedia Commons, public domain.)
Since the 1970s, recycling has been a progressive
engineering solution to waste management. For example,
almost all old cars are now recycled into new consumer
products. (See Figure 44.) Some automobile factories boast of
not sending any waste to landfills. This will become
increasingly common.
Figure 45: Illustration of the steps in sorting domestic
waste for recycling. (Credit: Original image concept by
Robin Kerrod. Illustration by KVDP with permission
granted by Robin Kerrod, Wikimedia Commons, public
The process flow of separating general domestic waste for
recovery is shown in Figure 45. Today, much of the trash is
converted into bit-sized pieces for sorting, often unavoidably
generating waste that must be sent to a landfill. To overcome
this limitation, companies are now adding robotics, sensors,
and artificial intelligence (AI) to the process flow to reduce
the human involvement while increasing the quality of the
separated waste. For example, AI enables sorting based upon
the physical shape as well as the labels. AI-driven robotics will
enable trash to be recycled more effectively and efficiently,
reducing the amount of trash sent to landfills.
James Michael Snead, PE
Some companies are experimenting with robotic systems
that know how a device was built and, therefore, can
disassemble the device, part-by-part, enabling the separated
materials to be recycled into new products. Lights out
factories would be able to both produce and disassemble a
given product into its parts, perhaps enabling on-site direct
recycling back into new products.
With space-based sustainable energy, robotic factories
producing the recycling plants, AI-driven robotics doing the
recovery, and new community infrastructure designed to
robotically handle both the delivery and return of products
and waste, the entire productionusereturn flow can be
closed, enabling an important step towards a 22nd century
sustainable culture with minimal landfill waste (and no net
CO2 emissions!). It can also be anticipated that existing
landfills will be excavated and processed once waste recovery
becomes substantially automated. With space-based
sustainable energy, the cost of this would be almost zero.
Construction humanoids
Figure 46: The “Turk”, a chess-playing robot from the
late 1700s. (Credit: Karl Gottlieb von Windisch,
Wikimedia Commons, public domain.)
Humanoids capable of performing human actions have
been imagined since, at least, the late 1700s. The “Turk” was
a famous chess-playing robot that amused and entertained
people across Europe and the United States in the late 1700s
and early 1800s. (See Figure 46.) Benjamin Franklin played a
game with the Turk while he was America’s ambassador to
France. Of course, the Turk was an illusionbut one that
went undiscovered for decades. A chess master hid within the
cabinet, manipulating the chess pieces through ingenious
mechanisms. Yet, the Turk foreshadowed what is now
becoming reality.
James Michael Snead, PE
Figure 47: Humanoid constructed using 3D additive
manufacturing. (Credit: Oak Ridge National
Laboratory, U.S. Government work.)
3D additive manufacturing methods are being used to
develop humanoids capable of human-like movements. (See
Figure 47.) While this technology is still primitive, future
evolutions will enable construction humanoids to be built that
will be used in lights-out factories and at construction sites to
replace and augment human workers. Humanoids will further
decrease the human touch labor involved in producing new
products resulting in the economic cost of these products
falling even more. Humanoids will also, obviously, be used in
recycling, further automating this process.
Intelligent deconstruction
Figure 48: House demolition. (Credit: Nyttend,
Wikimedia Commons, public domain.)
Today, we use large machines to demolish buildings and
infrastructure, creating large piles of mixed rubble. (See
Figure 48.) Previously, the rubble was hauled to waste sites
and buried. Today, most construction ruble is now recycled in
some manner. The next advancement will be to use AI and
construction humanoids to deconstruct the building rather
than simply tearing it down.
Laser scanning now provides the ability to capture, three-
dimensionally, existing structures at a high-level of detail.
(See Figure 49.) With improved sensors, including
penetrating sensors, literally every nail and bolt used to build
the structure will be identified and precisely located. At the
same time, all of the materials will be identified. The materials
that can be recycled will be catalogued for recovery.
James Michael Snead, PE
Figure 49: Picture of a laser-scanned house. (Credit:
Historic American Building Record, National Park
Service, public domain.)
With this information, construction humanoids will be
directed to deconstruct existing buildings and infrastructure,
placing the selected materials directly into the recycling
stream separated by material. Built themselves with recycled
materials at lights-out plants and powered primarily by
space-based sustainable energy, a large construction
humanoid workforce will be able to deconstruct and rebuild
outdated buildings and infrastructure. Humans will provide
planning and supervision with, occasionally, direct
involvement using virtual reality to “step into” a construction
humanoid to tackle a “new” deconstruction step.
E. Closing thoughts
Figure 50: Community barn raising circa 1900. (Credit:
J. E. Curtis, Wikimedia Commons, public domain.)
An old American tradition was the community house- or
barn-raising. (See Figure 50.) To help a new family or farmer
get off to a good start, the community would come together to
build the basic house or barn. The materialsprimarily
timber, wood, and stonewould come from the farm. The
new homeowner or farmer would provide the hardware and
paint. The community would provide the labor. A feast would
customarily be held when the basic construction was
completedusually in only a couple of days.
This American tradition generally vanished around the
beginning of the 20th century as construction companies and
bank financing enabled homes and barns to be commercially
built. With house/barn-raising, donated (free) labor
combined with the (free) resources nature provided on the
homestead enabled homes and barns to be constructed with
essentially no residual financial burden. With bank financing,
the cost of the human labor to provide the materials and
construct buildings ends up as a residual financial burdena
James Michael Snead, PE
Figure 51: Illustration of how a home could be 3D
printed using concrete. (Credit: Contour Crafting
Corporation, used with permission.)
A version of 3D additive manufacturing is effectively
reviving the tradition of house/barn-raising by robotically
building with concrete. (See Figure 51.) Experimentation with
using this method to build multi-story buildings is underway.
Economically, the large 3D printer replaces a significant
portion of the human labor now required to build homes. This
is just the start of a trend to return to a way of building that
has no, or a low, residual financial burden.
At one time potable water was difficult and costly to
obtain in terms of the required human labor. Ancient Roman
engineers changed this paradigm by building aqueducts to
provide ample potable water. This progressive engineering
feat enabled, for its time, a futuristic city to be built.
Today, America is beginning a similar fundamental
paradigm shift. With 3D building construction, materials
largely provided by intelligent recycling and renewable
natural materials, components built in lights-out factories,
and construction humanoids clearing existing structures and
assisting in the new constructionall increasingly powered
by sustainable energya technological pathway to affordably
deconstructing old America and building anew for the 22nd
century is coming into being. Literally from the ground up,
American engineers will renew America for the 22nd century
at the same time other American engineers are transforming
America into a true human spacefaring nation.
Consider this: For a typical 2,450 square foot (228 square
meter) American home, with an attached garage and
unfinished basement, the embedded energy required to
provide the building materials and construct the home has
been estimated to be about 251,000 kWh or about 102 kWh
per square foot.
The cost of generating hydroelectricity is about $0.01 per
kWh. With the addition of the cost of transmission and
generation, the total delivered cost rises to about $0.05 per
kWh. This equates to an energy cost, using sustainable
hydroelectricity, of about $5 per square foot. The total energy
cost of building the home is about $12,000about 5 percent
of today’s cost using traditional methods. Also, due to the
substantially reduced energy consumption of a modern
energy-conserving home, the entire energy cost of its
construction would be recouped in less than a decade.
With the advanced deconstruction, recycling, and
construction technologies discussed and the increasing use of
sustainable electrical power to replace fossil fuels, why
wouldn’t all outdated homes, buildings, and
infrastructure in America be replaced as America
prepares for the 22nd century as a truly sustainable
society? By 2100, an almost entirely new, elegant America
could come into being while providing several generations of
science, exploration, technology, engineering, manufacturing,
construction, deconstruction, and energy-production jobs for
Americans both here and throughout the central solar system.
James Michael Snead, PE
When this renewal of America is combined with the war-
avoiding potential of GEO space solar power, the elimination
of anthropogenic CO2, the energy security provided by ending
the use on non-sustainable fossil fuels, and the realization of
America’s spacefaring dream, this is an inspiring vision of
what America’s engineers can achieve this century!
Chapter VIII: Why American
Engineers Should Advocate for
a National Astroelectricity
“One man’s “magic” is another man’s engineering.”
Robert A. Heinlein
Figure 52: The contiguous United States at night.
(Credit: NASA.)
James Michael Snead, PE
Figure 52 is a composite image of the United States at
night. The extent of our American civilization is readily visible
by the light produced.
As discussed earlier, roughly 80 percent of the American
culture that these lights represent is powered by non-
sustainable fossil fuels. Also, as discussed earlier, the vital
remaining technically recoverable domestic oil and natural
gas resources powering about two-thirds of this culture will
be exhausted this century.
To avoid cultural collapse later this century, American
engineers have a professional obligation to see that these
fossil fuel energy sources are replaced in an orderly manner
to prevent energy supply disruptions. This will require
building in the ballpark of 5000 GW of replacement
continuous sustainable electrical power generation capacity.
As the previous analyses indicated, while some of this will be
provided by terrestrial wind and ground solar, the majority of
the replacement sustainable electrical power supply can only
practically come from astroelectricity. In the process of
making this unavoidable conversion, engineers will also
enable America to end its production of anthropogenic CO2
emissions from fossil fuels.
There is no political or legal remedy for solving the twin
environmental and energy security threats posed by
America’s use of fossil fuels that will preserve America’s
freedom and economic prosperity. These threats can only be
resolved by a well-executed progressive national engineering
effort to replace fossil fuels with new sustainable electrical
power sources.
American engineers must step up to the plate and take on
the challenges of preparing America for the 22nd century as an
ethical, sustainable nation-enabling prosperity for all. For
starters, American engineers should forcefully advocate for
GEO space solar power! (See Figure 53.)
Note: Just to be very clear, this use of “progressive” to
describe engineering works that advance America’s
security and prosperity is not related to the current
political use of the term “progressive” to describe
“solutions” aimed at achieving ideological objectives.
James Michael Snead, PE
Figure 53: Composite image of a 1976 NASA illustration of a
GEO space solar power platform being built and the image of
the Earth taken on the Apollo 8 mission in 1968. America now
has the engineering and industrial ability and clear need to
undertake GEO space solar power. (Composite image credit: J.
M. Snead.)
James Michael Snead, PE
Engineers lust for challenges that make each day’s efforts
rewarding, if not exhilarating. During the 1800s, American
engineers were bold in what they thought could be
accomplished and were not timid in conveying these thoughts
to the public. They promised and built canals, steamship lines,
railroads, water and sewer systems, and immense bridges.
Last century, even as they created our airlines, interstate
highway system, landed Americans on the Moon, and started
the Internet revolution, they became politically timid.
Now, threatening circumstances demand a public voice
from America’s engineers. For America to have a safe and
prosperous future requires substantial progressive
engineering solutionsmany described in this book. To turn
these into reality, requires that engineers have the
political guts to speak up and say “we can solve these
problems”. Continued timidity will bring failure to all.
Appendix A: Understanding
Energy and Power
As late as the 1830s, when America’s population was still
fairly small and wood fuel provided the nation’s energy,
America’s remaining forests met the annual fuel needs in a
sustainable manner. This means that annual new forest
growth equaled or exceeded the amount of wood fuel
consumed. America’s rapidly increasing population and the
start of the steam-powered industrial revolution soon shifted
the United States into a net deficit of technologically-available
sustainable energy. The United States has been running a net
sustainable energy deficit ever since the mid-1800s with
fossil fuels making up the deficit.
At that time, the unit of energy consumption was a cord of
wood fuela neat stack of dry wood measuring four feet wide
by four feet tall by eight feet long. As the United States
transitioned to fossil fuels, the standard unit of energy
consumption shifted to a short ton of coal and a barrel of oil.
These led to the barrel of oil equivalent (BOE) unit being
commonly used to measure energy production and
consumptionnot just fossil fuels, but all energy sources.
In 2015, the United States consumed a total of 16.7 billion
BOE of gross thermal energy (GTE) from all energy sources.
By 2100, this will likely grow to 25 billion BOE per year to
meet the needs of the expected 500 million Americans.
The only available sustainable energy sources which are
thermal fuels come from plants. These can only provide a
small percentage of America’s total energy needs. All of the
other possible sustainable energy replacements for fossil
James Michael Snead, PE
fuels produce electricityfor example, nuclear power,
hydroelectricity, and wind and ground solar power. To
quantitatively discuss America’s transition this century to
sustainable energy, America’s need for 25 billion BOE per
year of energy must now be restated in terms of electrical
power and electrical energy. In this appendix, the difference
between electrical power and energy is discussed.
1. Electrical power
Modern sources of sustainable energy are expressed in
terms of the electrical power and electrical energy they
produce. While electrical power and electrical energy are
often used interchangeably in common conversation, the
difference is important to understand.
When an electrical appliance is turned on, such as a
common microwave oven, an electrically conductive circuit is
completed (closed) connecting the appliance to the generator
producing the electricity. This circuit enables electrical power
to flow from the generator through miles of distribution and
transmission wires to supply power to the appliance. To turn
the appliance off, the circuit is said to be opened. Each of us
closes and opens these circuits many times a dayevery time
we turn something on or off. This is a convenience of modern
life that we all take for granted.
When the appliance is operating, the magnitude of the
power being used is expressed in terms of the unit “watt”. For
example, a typical small microwave oven will consume 1000
watts (W) of electrical power when operating.
Scientists and engineers utilize prefixes to abbreviate
large numbers. The prefix for 1000 is kilo, which comes from
the Greek expression for 1000, such as in “kilometer” for a
length of 1000 meters. The microwave oven would be
described as using 1 kilowatt of power.
= 1000
If folks in 1000 homes all turned their 1-kilowatt ovens on
at the same time, the total additional power being used would
be 1000 kilowatts or 1,000,000 (million) watts. The prefix for
1,000,000 is mega, which comes from the Greek expression
for great. Thus, 1 megawatt of power is being used by the
1000 microwave ovens in this example.
= 1,000,000
If folks in 1000 towns, each with 1000 homes having a 1-
kilowatt oven, all turned on their ovens at the same time, the
total additional power being used would be 1,000,000
kilowatts or 1,000,000,000 (billion) watts. The prefix for
1,000,000,000 is giga, which comes from the Greek
expression for giant. Thus, 1 gigawatt of power is being used
in this example.
= 1,000,000,000
Scientists and engineers use abbreviations for each of
these three terms.
k = kilo
M = mega
G = giga
kW = kilowatt
MW = megawatt
GW = gigawatt
The Hoover Dam can generate about 2 billion watts of
electrical power when operating at full power.
= 2,000,000
James Michael Snead, PE
= 2,000
= 2
From the example, the 2-GW Hoover Dam could power 2
million 1-kW microwave ovens. This example provides a
handy mental image of what the term GW meansthe
electrical power used by 1 million microwave ovens.
2. Electrical energy
Figure 54: Hoover Dam powerhouse. (Credit: Bureau of
Reclamation, Wikimedia Commons, public domain.)
One of the Hoover Dam’s two powerhouses, containing the
turbine generators, is shown in the 1940 photograph above.
(See Figure 54.) Hydroelectricity is a renewable energy
Lake Mead is the reservoir formed upriver of the dam to
supply water to the turbine generators. While Hoover Dam
can produce up to 2 GW of electrical power, it can’t do this
indefinitelyonly as long as there is sufficient water in Lake
Mead. Therefore, the amount of water in Lake Mead defines
how long the turbines can run and, thus, how much energy
Hoover Dam can produce.
Energy is the product of the power generated (or
consumed) multiplied by the length of time the power is
generated (or consumed).
If a 1-kW microwave oven is turned on for one hour, it will
consume 1 kilowatt-hour (kWh) of electrical energy.
× 1
= 1
kilowatt-hour (kWh)
The Hoover Dam, operating at full capacity for one hour,
would generate two gigawatt-hours of electrical energy or 2
GWh. Thus, while power is expressed using only the unit
watt, energy also has a time component. The time
component could be second, minute, hour, day, month, or
year. When discussing national energy needs, the GWh and
the GW-year units are often used. For home electrical energy
use, the kWh is used. A typical home uses about 1000 kWh per
month; more if air conditioning or electrical heating is used.
James Michael Snead, PE
Appendix B: Energy Required
to Produce Hydrogen
Most energy now used in the United States is produced by
the combustion of fossil fuels. Combustion liberates the fuel’s
thermal energy. This thermal energy is used to generate
electrical power, produce mechanical power, and produce
heat. For fossil fuels, the barrel of oil equivalent (BOE) unit is
used to establish how much thermal energy is being
produced, consumed, or remains in the endowment.
Sustainable energy systems usually produce electrical
energy directly. Thus, the appropriate energy unit for
discussing sustainable energy is the watt-time. As mentioned
in Appendix A, the common units used are the kWh, the GWh,
and the GW-year.
Replacing fossil fuels with new sustainable energy sources
will require that both electrical energy and fuel be provided.
In most cases, the electrical energy produced by a continuous
or baseload sustainable energy system, e.g., the Hoover Dam,
will be sent directly to the end users. To replace a fossil fuel,
for example, gasoline, hydrogen fuel is assumed to be
produced, using sustainable electrical energy and electrolysis,
to meet the end user’s need for a combustible fuel.
1. Hydrogen
Hydrogen is the most plentiful element in the universe. It
has the simplest atomic structure with one proton forming
the atom’s nucleus. It is also the lightest element. It does not
turn into a liquid until cooled to -423 °F (-253 °C). As a liquid,
it has a very low density of 4.42 pounds per cubic footonly
about seven percent of the density of water.
Figure 55: An electric current passing through water
separates the water molecule into oxygen and
hydrogen. This is how electrolysis works. (Credit:
Warren Gretz, National Renewable Energy Laboratory
for the U.S. Department of Energy, used as permitted.)
Hydrogen gas combusts with free oxygen to form water
(H2O) while releasing thermal energy. This is called an
exothermic reaction. This particular chemical reaction is
reversible. By applying electrical power or heat, the water’s
molecular bonds can be broken, liberating free hydrogen and
free oxygen as gases. When electrical power is used to break
the bonds, this is called electrolysis something most of us
have done in a high school chemistry lab. (See Figure 55.)
When the electrical energy comes from sustainable sources,
such as the Hoover Dam, the supply of hydrogen fuel also
becomes sustainable.
James Michael Snead, PE
Hydrogen as a fuel
To determine America’s sustainable energy need in 2100,
sustainable hydrogen will be assumed to be used to replace
fossil fuels used directly to produce heat. The starting point
for this analysis is to determine how much electrical energy
will be needed to produce one BOE of hydrogen fuel.
Each type of fuel has two sets of thermal heating values
referred to as the lower heating value (LHV) and the higher
heating value (HHV). The LHV is the amount of useful heat
liberated in simple applications such as automobile engines.
If the temperature of the engine’s exhaust is measured, the
exhaust temperature would be quite high. This high
temperature represents thermal energy that is being wasted.
In some special uses, such as gas turbines used to generate
electricity, most of the LHV waste heat is used to produce
additional electricity. In this case, the fuel’s higher heating
value is effectively used. For most carbon fuels, the numeric
difference between the two values is small and ignored. For
hydrogen, the difference is significantabout 18 percent.
Note: Calculations of key values used in these
discussions are included for those interested in these
details. Equations on the left define values or
relationships. In these equations, the notation “:=” is
used by the math program to define a value or
relationship. Equations on the right provide the
calculated values or units conversion. A “=” is used to
show that the result is a calculated value. The
engineering notation of 103 means 10 × 10 × 10 or
1000, 106 = 1 million, 109 = 1 billion, 1012 = 1 trillion,
The U.S. Department of Energy’s Hydrogen Analysis
Resources Center provides the LHV and HHV for hydrogen.
The values on the left express the LHV and HHV in terms of
Btu per pound of hydrogen. The values are those for Btu per
Recall that the barrel of oil equivalent (BOE) is defined in
terms of thermal energy content. A Btu is the amount of
thermal energy required to increase the temperature of 1
pound (2 cups) of water by 1 °F.
= 5,800,000
Using the BOE unit, the weight, expressed as pound-mass
(lbm), or metric mass (kg) of hydrogenwhether gas or
liquidthat yields one BOE of thermal energy are calculated
for both the LHV and the HHV cases.
The difference between the LHV and HHV cases for
hydrogen shows up in the weight or mass of the hydrogen
required to equal one BOE. When some of the available
thermal energy is lost in the exhaust, as with the LHV case, it
takes more hydrogen to yield 1 BOE of thermal energy. For
this reason, 18 percent more sustainable electrical energy is
required to produce 1 BOE of hydrogen if combusted under
James Michael Snead, PE
LHV conditions compared to producing hydrogen for use
under the more efficient HHV conditions.
For most hydrogen fuel uses, 50.9 kg (112.2 lb) of
hydrogen would be needed to provide 1 BOE of thermal
energy. For combustion under HHV conditions, such as co-
generation systems, only 43 kg (94.9 lb) would be needed.
This difference is taken into account when estimating the
total sustainable energy needs of the United States in 2100.
Electrolyzer efficiency
For everything that uses energy, some input energy
unavoidably becomes waste heat because chemical or
mechanical processes are not 100 percent efficient. The same
is true for electrolyzers that convert water into free hydrogen
and oxygen. Some of the input electrical energy is lost as
waste heat warming the water.
The U.S. Department of Energy has established a goal to
develop industrial-scale electrolyzers that are 75 percent
efficient. (9) (10) This means that only 25 percent of the input
electrical energy is lost as waste heat. Achieving this goal
would yield an input energy rate of 44.7 kWh per kg (20.276
kWh per pound) of hydrogen gas produced. For comparison,
current experimental electrolyzers are operating in the range
of 54-65 kWh per kg meaning that current electrolyzers
require up to 45 percent more input energy. For this analysis,
America’s 2100 energy needs are calculated using the
optimistic goal of 44.7 kWh per kg (20.276 kWh per pound).
Keep this in mind when total U.S. sustainable energy needs in
2100 are being determined.
Recall that the microwave oven consumed 1 kW of
electrical power per hour. In 20 hours and 17 minutes of
continuous operation, it would use 20.276 kWh of electrical
energy. This is the same amount of electrical energy needed
to produce just one pound of hydrogen gas at the goal
electrolyzer efficiency. If the oven operated continuously for
95 days, it would use the amount of electrical energy needed
to produce <