James M. Snead, PE
Beavercreek, Ohio, USA
November 19, 2008
(The PDF of the entire paper is here.)
Easy energy refers to the current oil, coal, and natural gas energy sources that provide about 86% of the U.S.’s and the world’s energy. An increasing average world per capita demand for easy energy combined with a growing U.S. and world population will exhaust recoverable resources of easy energy this century, probably within the lifetime of today’s young children. Current sustainable nuclear and renewable energy sources provide only about 14% of the world’s electricity and modern fuel needs. To meet the world’s projected 3X increase in energy needs by 2100, if not decades earlier, today’s sustainable energy production must expand by a factor of over 24X. This paper’s assessment of the energy production potential of conventional nuclear, geothermal, wind, ground solar electric, and land biomass finds that these will fall significantly short of both the U.S.’s or the world’s 2100 sustainable energy needs. To fill the substantial sustainable energy shortfall that will emerge by 2100 as the era of easy energy ends, space solar power and algae biodiesel—absent the extensive use of advanced nuclear energy and/or undersea methane hydrates—will need to be substantially developed. Space solar power will be needed to supply most of the U.S.’s and the world’s dispatchable electrical power generation capacity while hydrogen produced with off-peak space solar power electricity and algae biodiesel will be needed to fill the fuels shortfall.
[Author’s update: At the time this paper was written algae biofuel appeared to be a potential terrestrial approach to producing hydrocarbon fuels to replace fossil fuels. In 2016, the potential for large-scale use of this approach has diminished as commercialization has proven to be difficult – especially open pond approaches. This means that another sustainable source of fuel will be needed. In later papers, sustainable space-based power used to produce hydrogen is the presumed approach.]
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1. By 2100, the number of people actually using electricity and modern fuels will more than double. Of the world’s current 6.6 billion people, 2.4 billion do not have access to modern fuels and 1.6 billion do not have access to electricity. As a result, a substantial percentage of the world’s population lives in a state of energy deprivation that substantially impacts health, individual economic opportunity, social and political stability, and world security. By 2100, the world’s population is projected to climb another 3.4 billion to roughly 10 billion. This means that by 2100, an additional 5-6 billion people, not using modern fuels and electricity today, must be provided with assured, affordable, and sufficient energy supplies if the world’s current energy insecurity is to be substantially eliminated.
2. By 2100, to meet reasonable energy needs, the total world’s energy production of electricity and modern fuels must increase by a factor of about 3.4X while that of the United States must increase by a factor of 1.6X. The annual per capita total energy consumption of Japan, South Korea, and Europe averages about 30 barrels of oil equivalent or BOE. Further energy conservation may reduce this to about 27 BOE per year. This value is used in this paper as a level of energy consumption needed for a modern standard of living and a stable political and economic environment outside the United States. By 2100, should the non-U.S. world population achieve this modern “middle class” standard of living, the world will require an annual energy supply of around 280 billion BOE. In 2006, the world’s electricity and modern fuels energy supply was about 81 billion BOE. Hence, by 2100, the world will need on the order of 3.4X more energy than was being produced in 2006. In the United States, a near doubling of the population by 2100, even with a 20% reduction in per capita energy use, will require a 1.6X increase in U.S. energy needs.
3. If oil, coal, and natural gas remain the predominant source of energy, both known and expected newly discovered reserves will be exhausted by 2100, if not far earlier. Of the 81 billion BOE produced each year from all energy sources, 86% or 70 billion BOE comes from non-renewable oil, coal, and natural gas. At this percentage, by 2100, the world would need about 240 billion BOE from oil, coal, and natural gas. With an annual average of about 155 billion BOE through the end of the century, the world would need about 14,100 billion BOE of oil, coal, and natural gas to reach the end of the century. Current proved recoverable reserves of oil, coal, and natural gas total only about 6,000 billion BOE. Expert estimates of additional recoverable reserves optimistically add another 6,000 billion BOE—for example, including nearly 3,000 billion BOE from all oil from oil shale—for a combined total of around 12,000 billion BOE. With increasing world energy consumption and if oil, coal, and natural gas continue to provide most of the world’s energy, known and new reserves of oil, coal, and natural gas will be exhausted by the end of the century, if not much earlier.
4. To transform the world to primarily sustainable energy by 2100 to replace oil, coal, and natural gas, current sustainable energy sources must be scaled up from today by a factor of 24. By the end of the century—perhaps decades earlier—the world will need to obtain almost all of its energy from sustainable energy sources: nuclear and renewables. Today, the equivalent of about 11 billion BOE comes from sustainable energy sources. By 2100, the world must increase the production capacity of sustainable energy sources by a factor of about 24 to provide the equivalent of 280 billion BOE. The two primary sources of sustainable energy today are nuclear and hydroelectric. Today, the world has the sustainable energy equivalent of about 350 1-GWe (gigawatt-electric) nuclear power plants and 375 2-GWe Hoover Dams. To meet the world’s 2100 need for 280 billion BOE of energy production, every four years through the end of the century, the world must add this amount of sustainable energy production in the form of nuclear, hydroelectric, geothermal, wind, solar, and biomass.
5. Terrestrial sources of sustainable dispatchable electrical power generation will fall significantly short of U.S. and world needs by 2100 and, even, current U.S. needs. Energy is supplied in two primary forms: dispatchable electrical power to meet consumer needs for electricity and modern fuels to power transportation and other systems operating off the electrical power grid. By 2100, the world will need about 18,000 GWe of dispatchable electrical power generation capacity, compared with about 4,000 GWe today, with almost all generated by sustainable sources. To assess the potential of nuclear fission and terrestrial renewables for meeting this world need, the addition of 1,400 1-GWe conventional nuclear fission reactors , the construction of the equivalent of 1,400 2-GWe Hoover Dams for added hydroelectric power generation, the addition of 1,900 GWe of geothermal electric power generation, and the expansion of wind-generated electrical power to 11 million commercial wind turbines, covering 1.74 million sq. mi., would only be able to supply about 47% of the world’s 2100 need for dispatchable electrical power generation capacity. For the United States, only about 30% of the needed 2100 dispatchable electrical power generation capacity could be provided by these sustainable sources. By 2100, the U.S. and the world would be left with a dispatchable electrical power generation shortfall of 70% and 53%, respectively, with respect to this paper’s projection of the 2100 needs. Further, for the United States, the projected 2100 sustainable generation capacity would only provide about one-half of the current installed generation capacity that relies substantially on non-renewable coal and natural gas.
6. Expanded conventional renewable sources of sustainable fuels—hydrogen, alcohol, bio-methane, and bio-solids—will not be able to meet the U.S.’s or the world’s 2100 needs for sustainable fuels. To assess the potential for conventional renewable sources of sustainable fuel for the entire world in 2100, hydrogen production from the electricity generated by nearly 600,000 sq. mi. of ground solar photovoltaic systems, hydrogen production from over 80% of the electrical power generated by 11 million wind turbines, and biofuels produced from 13,000 million tons of land biomass from the world’s croplands and accessible forestlands would only be able to supply about 37% of the world’s 2100 need for sustainable fuels. For the United States, by 2100, the situation is about the same with only about 39% of the 2100 needed fuels production capable of being provided from these conventional sustainable energy sources. As with sustainable electrical power generation, conventional sustainable U.S. fuels production at projected 2100 levels would fall well short of meeting current U.S. needs for fuel.
7. Closing the U.S.’s and the world’s significant shortfalls in dispatchable electrical power will require substantial additional generation capacity that can only be addressed through the use of space solar power. Because of the substantial shortfall in needed 2100 fuels production, producing even more sustainable fuels to burn as a replacement for oil, coal, and natural gas to generate the needed additional electrical power is not practical. As a result, additional baseload electrical power generation capacity must be developed. The remaining potential sources of dispatchable electrical power generation are advanced nuclear energy and space solar power. While advanced nuclear energy certainly holds the promise to help fill this gap, fulfilling its promise has significant challenges to first overcome. Demonstrated safety; waste disposal; nuclear proliferation; fuel availability; and, for fusion and some fission approaches, required further technology development limit the ability to project significant growth in advanced nuclear electrical power generation. Space solar power (SSP)—involving the use of extremely large space platforms (20,000 or more tons each) in geostationary orbit (GEO) to convert sunlight into electrical power and transmit this power to large ground receivers—provides the remaining large-scale baseload alternative. Relying on SSP would require 1,854 5-GWe SSP systems to eliminate the world’s shortfall in needed 2100 dispatchable electrical power generation capacity. Of these, 244 SSP systems would be used to eliminate the U.S. shortfall in needed 2100 dispatchable electrical power generation capacity. The following two charts summarize this paper’s projection of the potential contribution of SSP in meeting the U.S.’s and the world’s dispatchable electrical power generation needs in 2100.
8. In addition to eliminating the dispatchable electrical power generation shortfall, SSP could, with algae biodiesel, eliminate the sustainable fuels production shortfall. Excess SSP electrical power can be used, when demand is less than the SSP generation capacity, to electrolyze water to produce hydrogen. Closed-environment algae biodiesel production, done on the land under each SSP receiving antenna, combined with SSP hydrogen production can provide 24% and 19% of the United States’ and the world’s 2100 needed fuels production, respectively. The remaining fuels gap would be closed by warm-climate, open-pond algae biodiesel production. These two forms of sustainable fuels production—SSP hydrogen and algae biodiesel—would provide slightly more that 60% of this paper’s projection of the U.S.’s and the world’s 2100 needs for sustainable fuel production, as seen in the two charts below.
9. Recognizing that the dedicated land area required in the United States to install the needed renewable energy production systems will be substantial, SSP provides one of the highest efficiencies in terms of renewable energy production capacity per sq. mi. of all the renewable alternatives. In the United States, 375,000 sq. mi.—about 12% of the continental United States—would be directly placed into use for renewable energy generation to meet this paper’s projection of 2100 energy needs. (For comparison, the U.S. arable and permanent cropland totals 680,000 sq. mi.) This land would be 100% covered with wind farms, ground solar photovoltaic systems, SSP receiving antennas, and open-pond algae biodiesel ponds. Of these four renewable energy options, SSP is one of the most land use efficient. The 244 SSP receiving antennas would require only about 20,000 sq. mi. or about 0.6% of the continental U.S., while providing nearly 70% of the dispatchable electrical power generation capacity and about 24% of the sustainable fuels production capacity by 2100.
- Based on this assessment’s findings, a sound U.S. energy policy and implementation strategy should emphasize:
- Finding and producing more oil, coal, and natural gas to meet growing demand in order to minimize energy scarcity and price escalation during the generations-long transition to sustainable energy supplies;
- Adopting prudent energy conservation improvements to reduce the per capita energy needs of the United States, as well as the rest of the world, without involuntarily reducing the standard of living;
- Aggressively transitioning to conventional nuclear and terrestrial renewable energy sources to supplement and then replace oil, coal, and natural gas resources to avoid dramatic reductions in available per capita energy as non-renewable energy sources are exhausted this century; and,
- Aggressively developing advanced nuclear energy, space solar power energy, and open-pond/closed-environment algae biodiesel production to fill the substantial projected shortfalls in sustainable electrical power generation and fuels production that will develop even with optimistic levels of conventional nuclear and terrestrial renewable energy use.
- While it is certainly easy to be disillusioned by these findings, this need not and should not be the case, especially in the United States. The world and the United States have successfully undergone a comparable transition in energy sources when wood was no longer sufficient to meet the growing needs of a rapidly industrializing world. When the transition to coal started in earnest in the 17th century, steam power, electrical power, internal combustion, and nuclear energy where yet-to-be-invented new forms of energy conversion that now power the world. For about four centuries, technological development, economic investment, and industrial expansion— undertaken to realize the potential of “easy energy”—have been a foundation of the world’s growing standard of living and the emergence of the United States as a great power. Now, recognizing that the end of easy energy is at hand, the United States needs to aggressively move to expand existing sources of sustainable energy and develop and implement new sources to foster continued technological development, economic investment, and industrial expansion in the United States during the remainder of this century. It is critical that the United States take a leadership position in the development of space solar power as this may become the dominant electrical power generation capability for the world.