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Energy in transition
Applied Energy 23 (1986) 171-187
Energy in Transition*
Laurence O. Williamst Martin Marietta Orlando Aerospace, Box 5837, Orlando, Florida, 32855 (USA)
S UMMA R Y A plentijul, benign energy supply is essentialjor a high standard of living. In the near future the current temporary oil surplus will be exhausted and we will experience energy shortages and increasing prices. The surplus is not the result of the discovery of significant new oil. Its cause is a ponderous supply system feeding oil to a world economy with reduced demand resulting from successful conservation and recession. The surplus has depressed research and development, reducing our ability to respond to future shortages and rising prices. Decreasing or eliminating the combustion of Jossil fuel materials as energy sources will be very beneficial for the long-term fossil fuel materials are very valuable as chemicalsJ~,edstocks. Combustion offossil ,fuels is the source of most air pollution and acid rain. Carbon dioxide placed irreversibly in the atmosphere may cause dramatic shifts in climate and higher sea levels. New ideasfor energy sources and systems are needed. Expanded use of coal and shale oil will increase environmental damage. Fission nuclear energy has promise but has difficulties that nearly paralyze the industry. Fusion languishes from lack of research funds. Renewable energy systems have not shown much promise for large-scale use. New energy systems will require years to develop and implement. The cost will be high anda great deal of energy will be required. The technical community should exert leadership to implement this work now, while low cost energy remains available and the economy is relatively strong. * The opinions expressed in this article are those of the author and do not represent the official position of Martin Marietta Orlando Aerospace. t Present address: 4915 Caspian Court, Orlando, Florida 32819, USA. 171
Applied Energy 0306-2619/86/$03-50 ~' Elsevier Applied Science Publishers Ltd, England, 1986, Printed in Great Britain
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Laurence O. Williams A system with fusion as the prime energy source, and hydrogen as the storage and distribution medium, is suggested as a potential candidate system to supply benign plentiful energy for the future.
THE P R O B L E M S A high standard of living requires a clean, healthy environment and largescale per capita use of energy and raw materials. The need for a clean, healthy environment is self evident. The need for energy and raw materials is demonstrated both by the logic that energy and raw materials amplify an individual's ability to accomplish tasks with increased productivity and by the examination of the relationship between per capita energy use and per capita gross national product of the nations, as shown in Fig. 1. This Figure indicates that nations using the most energy tend to have the highest standard of living. A group of economists has performed analyses that indicate, essentially, that all improvements in productivity and living standards are a direct function of the amount of energy used. In their analyses the term Energy Return On Investment (EROI) is used to describe the economic impact of a particular energy form on productivity and living standards. Energy sources with a high EROI increase productivity and living standards more than sources with a low EROI. Of the c o m m o n fuels, natural gas has the highest EROI, petroleum is a close second and coal has the lowest. Derived energy forms, such as electricity, have higher EROI's than the source fuels. As a result, it is economically advantageous to use many energy units of a low EROI fuel, such as coal, to make a smaller number of energy units of a high EROI energy form, such as electricity. Not all economists agree that this approach is valid, but the strength of the correlations obtained indicates that energy has a profound impact on the economy. They also show that much current economic analysis does not give proper attention to the effects of energy supplies and cost on the growth of the world economy. 1'2 To improve, or even maintain, world-wide living standards, strong efforts must be made to implement an energy strategy that will ensure high EROI, environmentally benign, bountiful energy sources for the future. In this paper a synoptic analysis of our near term energy situation will be presented: this analysis indicates that there will be severe problems involving supplies and environmental degradation after 1995. A potential energy system solution for these problems is outlined.
Energy in transition
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Fig. I. Energy use as it relates to gross national product. The regression line is for 108 nations using data from 1980 Information Please Almanac (New York, Simon and Schuster) p. 134. The nations plotted have G N P per capita greater than $1000. I 2 3 4 5 6 7 8 9 10 11
Argentina Australia Austria Belgium Brazil Bulgaria Canada Chile China Costa Rica Czechoslovakia
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In 1977 three energy sources provided the bulk of the energy used in the United States: 3 fossil fuels, 91.5 per cent; nuclear energy, 4.5 per cent and hydro-electricity, 3.9 per cent. A roughly similar breakdown of sources is true for all industrialized nations, with fossil fuel combustion supplying over 90 per cent of the energy. The most desirable fossil-fuel sources will be exhausted within the lifetimes of more than half the people living today. Once the fossil-fuel reserves are consumed it will take millions of years for the natural formation processes to replace them. Their depletion will not only cause energy shortage problems, but the chemicals found in fossil fuels have a broad spectrum of alternate higher value uses and are nearly irreplaceable in these applications. In addition, their extraction and combustion are harmful to the environment. Thus far it has been difficult, or impossible, to attach appropriate monetary values for the environmental harm to the costs of the fuels. As a result, the current price of fuel paid by users is significantly less than the actual cost to world society. Irrespective of our. current dependency, the future higher value uses, and the present and future environmental damage caused by fossil fuel, it will be necessary to find replacement energy sources in the near future. Proven world oil reserves are estimated to be 640 billion barrels 4 and current world consumption is about 22 billion barrels per year. 5 Thus, at present rates, proven world reserves will be exhausted in about 30 years. If consumption increases at 2 per cent per year, the time to exhaustion will be 20 years. If the developing nations achieve their goals for improvements in living standards, their expanded use of oil will cause fuel consumption t o increase at rates higher than 2 per cent and exhaustion will occur even sooner. More oil may be found, but the evidence indicates that greater effort will be required to find each new smaller oil field, and the EROI of these fields will continue to decrease. The oil found will extend the time to exhaustion by no more than a few years. 7 The chemicals present in the fossil fuels are of extreme value in the production of a long list of materials useful or necessary for modern civilization. This list includes plastics, rubber, synthetic textiles, paint, drugs, lubricants and agricultural chemicals. Each May the American Chemical Society publishes a list of the 50 chemicals produced in the largest quantities in the United States. For 1984 the total production of organic chemicals, made largely from fossil-fuel chemicals, was 168.99 billion pounds weight. The largest production of a fossil-fuel chemical was recorded for ethylene (fifth overall) at 31.18 billion pounds. Ammonia, ammonium nitrate, a m m o n i u m sulfate and urea are produced
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from hydrogen derived from fossil fuels. Their production level of 64.85 billion pounds can be added to the fossil-fuel derived chemical products. Twenty-eight of the top fifty are chemicals from fossil fuels: four are made from hydrogen derived from fossil fuels. 6 While it is possible theoretically to make these chemicals from other sources of carbon, i.e. shale oil, wood, straw, or other plant-derived feedstocks or even the carbon dioxide from the air, the cost would be very high. Our combustion of the planet's easily recovered hydrocarbon resources for fuel will condemn future generations to obtain petroleumbased chemicals from other sources at much higher costs, or to do without. 7,8 A large portion of environmental pollution is the result of extraction and use of fossil fuels. The sequence of environmental damage begins with the recovery of the fuels from their natural deposits. 9 The soil in the vicinity of coal mines or oil wells becomes contaminated with fuel residues and the minerals associated with the fuels. All fossil fuels contain sulfur, and low levels of many other toxic elements such as selenium, arsenic and beryllium. Oxidation of the sulfur leads to acid mine drainage. Selenium, beryllium and similar toxic elements are leached into the acidic waters. In the vicinity of the deposits, this pollution is often so extreme that no use of the land is possible for many years after the fuel recovery is completed. Away from the source, the acid mine drainage can poison streams, rivers and lakes as the toxic contaminants are carried to the sea. Subsidence of the ground, as a result of fossil fuel recovery, is a worldwide problem. In Texas and California the pumping of oil has caused the ground to subside, changing the course of rivers and allowing the sea shore to move inland. 1o Oil pumping has also allowed the intrusion of salt water into previously fresh water wells, so preventing their use for drinking water or irrigation. In the eastern states such as Pennsylvania the cavities left by coal mines are collapsing (and occasionally burning), so destroying farm land and towns. Ordinary air pollution (smog) is largely the immediate result of the combustion of fossil fuels for energy. Smog is caused by complex chemical interactions of partly-burned fossil-fuel chemicals reacting with one another, and the oxygen and ozone in the air. These reactions are enhanced by the ultraviolet radiation from the sun. Smog causes health problems, damage to plants and structural damage to buildings. The costs of smog damage are difficult to ascertain because they are diffuse and difficult to separate from other forms of ageing and weathering. Even when some definition is possible, it is difficult to assess costs because they
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cannot be traced to any single source. Total smog damage costs are estimated to be quite high but they are borne by the public at large with little clear knowledge of their magnitude, a Acid rain is caused by sulfur dioxide produced by the oxidation of sulfur in the fossil fuels and the nitrogen oxides that are a product of all high-temperature combustion processes that use air. The sulfur dioxide and nitrogen oxides react with the water and oxygen in the air to produce sulfuric and nitric acids, respectively. The effects of acid rain are even less understood than the effects of smog. It has been implicated in the death of trees and the sterilization of lakes in both the United States and Europe. The acid rain directly damages foliage, it leaches nutrients from the soil and it mobilizes minerals such as aluminum in a water-soluble form. Once in solution, the mobilized minerals can be taken up by plants with adverse effects. They can drain into lakes and rivers where they have toxic effects on the aquatic life. The severity of acid rain effects appears to be regional. In parts of the country where the soil has high acid buffer capacity, the effects are limited to direct damage to foliage. Where soil has little buffer capacity, such as in the north-eastern United States, eastern Canada, central Europe and the Scandinavian countries, the acid rain effects may be acute today. 1~ Smog and acid rain products have a relatively short lifetime in the atmosphere.a a The chemicals responsible for the pollution are relatively soluble in water and rainfall removes them rapidly from the air. The reason that they have become a problem is that we continue to produce them at a very high rate. If the burning of fossil fuels is stopped, these pollutants would be cleared from the atmosphere in a time as short as a few months. The type of fossil-fuel air pollution least understood, but possibly the most damaging in the long run, is the essential irreversible addition of carbon dioxide to the atmosphere.12 About half of the fossil carbon dioxide produced is absorbed in the surface layers of the ocean; the rest remains in the atmosphere. It is known with good accuracy that the atmospheric concentration has increased from 295 parts per million prior to 1900 to a value of 340 parts per million today, a 15 per cent increase. 12,13 The portion that is absorbed in the ocean causes a change in acidity and in the ratio of carbonate to bicarbonate ions. This change will interfere with the ability of animals to deposit carbonate shells, with the potential of causing mass extinction.14 Carbon dioxide, which is not absorbed by the oceans, changes
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atmospheric thermal properties in a way that results in trapping more heat on the surface of the earth. How strongly increased carbon dioxide will influence the earth's heat balance is not well understood, but it is estimated that if energy generation continues to rely heavily on the combustion of fossil fuels, first using up the oil then shifting to coal, the carbon dioxide level will double by AD 2040. This doubling will increase the average global temperature by 3 to 5°C with the largest increase occurring at the poles where the increase may be as much as 20 °C. Initially, the temperature increase may only cause instability and shifts in the weather patterns, but eventually it will result in the warming of the earth's surface and the melting of polar ice.13 When this occurs, some time in the future, the sea level will rise, inundating coastal areas. If the long-term heating of the earth continues to the point at which all the ice melts, the sea level will rise hundreds of feet, thereby inundating much of the land currently occupied by mankind. 13 Coal is suggested as a substitute energy source, when petroleum depletion becomes critical. Unfortunately, coal has the lowest EROI of the fossil fuels. 1 Coal mining is very dangerous to the miners, its extraction is probably the most damaging to the land, its use introduces the largest quantity of sulfur and other toxic elements into the environment and, of all the fossil fuels, it produces the most carbon dioxide per unit energy developed. From the standpoint of the long-term health of the world, an argument that we should have avoided the use of fossil fuels for energy generation seems easy to justify, given their higher value use and the environmental damage that they cause. Our great dependence on them came about because of the ease of obtaining them, the relative simplicity of the technology required for their use and our lack of regard for their future higher value uses and knowledge of the long-term environmental effects. Because we lack the ability to properly determine future value and the knowledge to evaluate the cost of future environmental damage the near term EROI is high and their use has increased our contemporary standard of living. 1,2 Over the next 25 years, to replace petroleum fuel by synthetics, whether derived from shale, coal, nuclear or renewable sources, will require an enormous capital investment, in the range of $10 trillion in present dollars. This equates to $400 billion per year in new plant investment if started now. If we wait l 5 years, the bill will more than double and severe disruptions in the world economy will be inevitable. The lead time
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necessary to design, build, test and place new energy system facilities in operation is sufficiently long that facilities needed 10 years from now should be initiated within the next few years. Compared with fossil fuels, nuclear energy sources present a similar supply picture, but a rather different set of pollution problems. The amount of energy available by the use of once-through nuclear cycles, as is current practice, is in the same general range as that available from the remaining oil. 3 The nuclear industry has a far better safety record for protecting its own personnel and the public than does the fossil-fuel industry, 9 but the reaction by-products, while currently controlled, are accumulating and must be dealt with soon in an entirely safe manner or they will make a pollution problem of the same magnitude as that from fossil fuels.15 Two disposal methods are available, internment in stable geological formations and space disposal,16 but there is little agreement as to which is best or how we should go about implementing either. Because of the short lifetime and waste-product problems with the oncethrough nuclear fission energy cycle, it is, at best, an interim solution to the long range need for a benign energy source. Development and large-scale use of the breeder reactor cycles, uranium 238/plutonium 239; or thorium 232/uranium 233, would greatly increase the total amount of energy available from the use of fission nuclear reactors, but at the cost of much larger quantities of radioactive waste. The breeder cycles would allow the use of fission nuclear energy for hundreds of years without depletion of necessary resources.3 For this to be a viable solution, a totally safe system of waste disposal must be developed and agreed to by all concerned. A second, non-technical, problem arises from the use of the fission reactor systems. Both burner and breeder systems produce used fuel elements that contain fissionable isotopes of plutonium mixed with elements from which it can be chemically separated--a far easier process than the separation of isotopes required to obtain fissionable materials from natural uranium. In the planned course of events, this material would be reprocessed to provide for refuelling current or new reactors, but, unfortunately, it can be used to make nuclear weapons. This route to weapons-grade fissionable material is technically simple and low cost, when compared with the process required when starting with natural uranium. 17 This problem exists with either once-through systems or with breeder reactors, but, because the breeder cycle depends on this material
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for refuelling, there is much more of it in the inventory and a greater opportunity for undesirable diversion for weapons use. Hydropower and geothermal energy sources appear similar when examined as potential long-term energy sources for the future. Both have the potential to supply energy for a very long time and are relatively benign to the environment. Unfortunately, for either to be of value, it requires an unusual juxtaposition of natural geological conditions. In the United States most of the good sites for harvesting these forms of energy have already been exploited. ~ At present, these sources supply less than 4 per cent of the nation's energy and the outlook for future meaningful growth appears bleak. As the result of research in the late 1970s, production of energy from renewable resources such as sunlight and wind is beginning. Solar energy is in use for the supplemental heating of buildings and has been used in demonstration projects for the thermal and photo-voltaic generation of electricity. Wind is producing modest amounts of electric power. A small pilot plant has demonstrated that energy can be extracted from ocean thermal gradients. These renewable sources will, in the future, make some contribution to the total energy supplies of the world. The energy concentrations of solar, wind and ocean thermal gradient sources are low and harvesting them may require huge structures using large amounts of raw materials. Recent studies indicate that, on detailed environmental analyses of the large material requirements, certain renewable energy sources may cause as much environmental harm as current energy systems. The large amounts of raw materials that must be processed take large amounts of energy. For many renewable systems, the time required to obtain a net gain in energy is very long. 9 The renewable energy sources are often available only at inconvenient places and may produce energy only intermittently. They may provide a valuable supplement to energy supplies, but it will be necessary to have a large capacity reliable source to supply the bulk of the required energy. All these factors indicate that we have a serious energy problem, yet during the last few years the funding for energy research and development has been decreasing. This trend is very dangerous, but understandable if the energy situation is examined with only a very short-term view, e.g. five years into the future. From 1979 to the present the short-term energy situation of the oil importing nations has improved. Three factors have contributed to this
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improvement; they are:
1. Conservation The oil-importing nations mounted strong conservation efforts in the wake of the oil embargo in 1974. These efforts have succeeded well beyond expectations and the use of oil has been reduced substantially. 2. Deregulation In the United States, deregulation of oil prices and partial deregulation of natural-gas prices resulted in an increase in exploration for gas and oil and greater recovery from existing fields. 3. New Oil Fields The discovery of significant new oil fields by Canada and Mexico has greatly increased their exportation of oil to the United States. This made it possible for the United States to reduce its competition with Europe and Japan for Middle East oil. These factors have reduced the probability of severe shortages in the short term. The Strategic Oil Reserves instigated by the Department of Energy in the United States, and similar activities by other oil-importing countries, will aid in weathering any short-term shortages. Nevertheless, in the longer term, 5 to 15 years in the future, the availability of sufficient energy to sustain our present standard of living is doubtful, a'v'ls The current combination of stable or decreasing oil prices and high interest rates is eroding our resolve and ability to take the steps that would avert dire future consequences. This combination of factors is very dangerous for the long-run health of free nations. As time passes, and we adjust to energy shortages and higher prices, our ability to respond to the threat gets weaker and weaker because it will take energy and capital to provide a solution to the problem.~9 Inappropriate action by environmental groups has exacerbated the problem. Their focused attack on nuclear energy 9 in particular, and upon technology in general, simply ignores the fact that there is no way that the world could support a 21st century population with 19th and 20th century technology. Our continued well being, including food and secure shelter, depends upon energy availability, s There are serious environmental problems with all of our current energy sources, but, for the most part, environmentalists' actions have discouraged nuclear research so that today's reactors are based on older technology. These actions by anti-technology environmentalists may have seriously impaired the
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employment of nuclear-energy resources that may, in fact, be intrinsically less of an environmental threat than the continued combustion of oil and coal. The reduction in the growth of nuclear energy has resulted in serious efforts to increase the use of coal, the most polluting of all fuels. It seems likely that an increased use of nuclear energy will be necessary during the future transition from dependence on fossil fuels. The factors that have resulted in the current easing of the energy problem are insidious. Our situation can be likened to a person with a serious life-threatening disease, whose symptoms have been alleviated by pain-killing drugs. The euphoria of the drugs makes it difficult to concentrate on the need for a cure. Time is running out for the industrialized world. If we plan properly we can minimize the need for drastic solutions to alleviate the problem. Without firm plans our reactions will be dictated by the exigencies of the time, and the ultimate outcome will be uncertain.19 The problems of energy supplies and environmental protection are in no way hopeless if action is started soon enough. An energy development scenario that can lead to a system with potential for abundant environmentally-benign energy for centuries will be described to illustrate the type of future energy planning that will be necessary for the solution of the problem.
A F U T U R E ENERGY-SUPPLY SYSTEM In the near future, up until 10 years from now, we need to greatly increase our exploitation of the once-through nuclear cycle and all possible renewable sources. It may be desirable to require the exploitation of the gas-cooled reactors to help alleviate some of the fears concerning a disastrous reactor accident, z° Increased renewable and nuclear energy use will help prevent growth in the use of the most polluting fuel, coal, and ease the pressure on petroleum resources used for chemical production. Growth in nuclear energy will require agreement on methods of disposal of nuclear waste. Unaerground disposal has the advantage that the materials are available if future use is found for them. 15 The difficulty with underground storage lies in the need to monitor the waste for a very long time, a time longer than recorded history, or to come up with a method of storage that ensures that there is no possible way that the waste can leak into the environment for this same long period of time. No
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method of accomplishing either of these goals has been suggested that satisfies all critics. Space disposal has the distinct advantage that the waste can be placed in an orbit where there is no chance of contact with the earth for millions of years. 16 Space disposal has some appealing characteristics, but little study has been performed. It is not clear how it would be done or if it is practical. Whichever waste disposal method is selected we need to get the necessary implementation underway soon. In conjunction with increased emphasis on renewable energy resources and fission nuclear-energy, effort should be made to implement the use of hydrogen as the general purpose energy carrier. The outputs from renewable and nuclear-energy sources do not match well in space or time with the needs of the users. This leads to the requirement for an energy storage medium that can be easily implemented. Nuclear and renewable sources are both non-portable, leading to the requirement for a portable energy-storage medium to serve the vital transportation sector of the economy. Hydrogen can be used as the medium for coupling the sources to the users. In this application, hydrogen serves the same r61e as electricity. Its advantages over electricity are: it can be easily stored near the production or user site to provide load matching and reliability, it can be used directly as a transportation fuel and it can be piped continental distances with low losses in pipelines that are out of sight under the ground. There are a number of potential fuels that can be made by the application of energy to their synthesis. Examples are: (1) synthetic petroleum, methane and alcohols manufactured by reacting coal with hydrogen produced from water, (2) ammonia manufactured by reacting nitrogen from the air with hydrogen from water, and hydrogen manufactured from water. An essential step in all these processes is the production of hydrogen from water. Because all require the manufacture of hydrogen, and hydrogen has a far lower environmental impact than any of the other possible synthetic fuels, the use of hydrogen directly is very practical. The use of hydrogen to produce synthetic gasoline from coal would only provide a new way to add carbon dioxide to the atmosphere. Over the last 15 years, research has indicated that there are no technological barriers to the use of hydrogen as a general-purpose fuel. Most fuel-using devices and processes can be converted to hydrogen and the environmental damage caused by its use appears to be orders of magnitude less than that produced by other fuels. 21 Along with the effort to implement hydrogen fuel use, it will be
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necessary to push the development of fusion energy production for the ultimate replacement of the fission nuclear cycle. By this approach, we can avoid the use of the breeder fission cycles, with their greater production of radioactive waste, and avoid the need to greatly increase coal burning. The planning intent will be that the large number of fission reactors needed in the near term will be the last generation of the devices. In the longer term, energy will be provided by fusion reactors and carried by hydrogen. Fusion nuclear energy offers the potential for an energy source that could meet the requirements of the future .22 The raw materials used in the production of fusion power, deuterium, lithium and boron, are available in quantities large enough that the depletion is not possible for hundreds of thousands of years. 23 The fusion reaction will produce approximately one-thousandth the waste produced by the once-through nuclear-fission power cycle and only one-millionth of that produced by a breeder reactor energy system. A fusion reactor will be struggling at all times just to keep operating. There is no combination of failures or sabotage that would cause a blow-up type of accident. The modest quantities of long half-life waste produced (activated reactor structures) can be disposed of by the methods used with the interim fission reactors. These considerations indicate that the fusion reactor will be able to provide a safe, long life base load energy system. There are no products present in the fusion reactor that can be diverted for the production of primary weapons. The lithium and tritium used within the reactor are the ingredients used in thermo-nuclear weapons. But to make a working bomb, a uranium or plutonium trigger bomb is required. It would be feasible to use the neutrons produced by the deuterium-tritium fusion cycle for breeding plutonium from uranium. This use of a fusion reactor for the production of weapons-grade plutonium is theoretically possible but it would be very complex and would not appear to offer an easier path to weapons than is currently available. Current experiments and theory indicate that, as the size of a fusion reactor is increased, it becomes more feasible and efficient. As a result, the first fusion reactors will be large facilities both in physical size and in energy production. 24 This is often seen as a barrier to near-term implementation of fusion technology. When coupled with a hydrogen energy distribution system, the large size is no problem and, in fact, may be an advantage.
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The large fusion reactors can be located near, or floating on, the sea so that cold deep sea water can be used for cooling. The heat exchange system will be controlled in such a manner that the output cooling water will be rejected at the local surface temperature of the ocean. This will prevent ocean thermal pollution. In some locations, it may be advantageous to use a significant portion of the waste heat to desalinate sea water to add to potable water supplies. Some of the electrical power will be used in the vicinity of the reactor, but a large part of it will be used to electrolyze water for the production of hydrogen and by-product oxygen. Hydrogen will be used as the energy storage medium to match the unvarying output from the reactor to the variable demand, to serve as the storage and transmission medium and as the transportation fuel. The ease of transmitting a gaseous fuel, hydrogen, across continental distances will allow the construction of very large facilities and reap the maximum economies of scale. Many of the existing natural gas pipelines can be used, with relatively minor modifications, to carry the hydrogen. The by-product oxygen can be used in all current applications, but there will be far more available than is required. When polluted water is treated with pure oxygen the rate of purification is greatly enhanced. Some of the excess oxygen can be used for oxygen enhanced waste water treatment and to improve the quality of rivers and lakes. Any excess not used for specific industrial or environmental purposes can be vented to the air without any harm to the environment. The energy from the reactor is stored in the hydrogen produced by the splitting of water. When, at a later time, the hydrogen is burned the energy is recovered. The amount of hydrogen and oxygen produced by the reactor is exactly balanced by the hydrogen and oxygen used when the hydrogen is burned to recover the energy. As a result of this exact match there is no net addition of matter (such as carbon dioxide) to the environment by this energy system. The basic scientific knowledge is available for the production of fusion energy 22-24 and the adoption of hydrogen as the storable energy carrier. 21 Implementation of such a system would put an end to energy shortages and would stop the pollution that results from the use of energy. There is, however, a large amount of applied engineering research that must be performed and a number of barriers to overcome, before this system can provide energy routinely. The most difficult problem to overcome in the application of this or any solution to the energy dilemma is the enormous capital investment in the
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current fossil-energy systems. The replacement of these systems with new systems that the world can live with, for a long period, will require an equally enormous investment. This is, in fact, the most difficult problem we face, but we know that the current systems must be replaced eventually and the longer we wait, the higher the cost and the more difficult the solution will be to implement. Our procrastination will simply make the change even more difficult, when it is forced upon us by shortages of fuel and increased environmental degradation.19 This or any other solution will be met with all the c o m m o n challenges posed in an effort to resist change. These challenges will take the form of questions and statements such as: 'How extreme is the carbon dioxide problem?', 'Carbon dioxide will not effect us for a number of years', ~Fusion may not be feasible', 'Hydrogen is dangerous', and 'The current systems can be cleaned up'. These questions avoid the central issue that action is needed n o w . If, for example, we spend the next 10 to 15 years studying the carbon dioxide problem and find that we should have stopped adding it to the atmosphere today, we may be content with the scientific validity of the answer, but find that it is too late to save us from severe thermal pollution of the planet. Today, the feasibility of the fusion hydrogen energy system is similar to the feasibility of travel to the moon in 1960. In 1960 no one could provide the blue-prints for a moon rocket, but the essential principles were clear. With the proper attention to detail and a lot of hard work an 'Apollo' was built and it carried men to the moon. The essential principles of a fusion reactor and hydrogen utilization are clear. With the same approach the system can be built and it will provide energy. As it is enlarged, it will work better and cost less. By the time we are using the fusion hydrogen system for a tenth of our energy supply, the technology will be well in hand and we will be on the way to ending many forms of pollution and preserving the fossil fuel chemicals remaining for higher value use. There is no guarantee as to the cost of the energy but, when weighed against rising EROI of tbssil fuels and the enormous, but difficult-to-quantify cost of planetary pollution, the cost will be acceptable. If we spend the next 10 years quibbling over the details of a plan and performing expensive studies, we will waste both time and money to achieve a detailed description of the problem, but be no closer to a solution. This energy system, using whatever renewable energy can be harvested and with base load nuclear fusion reactors, will have a very long life. It will be able to supply the very large needs of the planetary population with
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minimal environmental damage. 25 It will be very high technology and the development will be a massive undertaking. The management, and research and development techniques, developed for programs such as 'Apollo' would seem to be the best method available for the implementation of this plan. It is the near-term responsibility of the technical c o m m u n i t y to provide the leadership to select a course of action that has a high probability of success and push hard for its implementation. Each day that passes without action makes the ultimate solution to the problem more difficult and costly. If we and our children are to survive in a clean, prosperous world, we must get started on our new energy system immediately.
REFERENCES 1. R. Costanza, Embodied energy and economic valuation, Science, 210 (December, 1980), p. 1219. 2. C. J. Cutler, R. Costanza, C. A. Hall and R. Kaufmann, Science, 225 (31 August, 1984), p. 890. 3. Energy in transition 1985-2010, Final Report of the Committee on Nuclear and Alternative Energy Systems--National Research Council, Washington DC, 1979. 4. S. Schurr, Energy and America's Future, Resources for the Future, Johns Hopkins Press, 1979. 5. Statistical Abstracts of the US 1984, Table 1525, US Department of Commerce. 6. C&EN's Top 50, Chemical and Engineering News (May 7, 1984), p. 7. 7. A. R. Flower, World oil production, Scientific American., 238(3) (March, 1978), p. 42. 8. W. Sassin, Energy, Sc&ntific American, 243(3) (September, 1980), p. 118. 9. H. Inhaber, Energy risk assessment, Gordon & Breach Science Publications, 1 Park Avenue, New York, NY, 1982. 10. S. S. Marsden, Jr., S. N. Davis, Geological subsidence, Scientific American, 216(6) (June, 1967), p. 93. 11. G. E. Likens, R. R. Wright, J. N. Galloway and T. J. Butler, Acid rain, Scientific American, 241(4) (October, 1979), p. 43. 12. R. Revelle, Carbon dioxide and world climate, Scientific American, 247(2) (August, 1982), p. 35. 13. G. J. MacDonald, (Ed), The long-term impacts of increasing atmospheric carbon dioxide let,els, Ballenger Publishing Company, Cambridge, Massachusetts, 1982. 14. A. W. Fairhall, Nature, 245 (September 7, 1973), p. 20. 15. B. L. Cohen, The disposal of radioactive wastes from fission reactors, Scientific American, 236(6) (June, 1977), p. 21.
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l 6. S. G. Rosen, Nuclear waste disposal in space. In: Macro engineering: The rich potential (R. Salkeld, F. P. Davidson and C. L. Meador, (Eds)), The American Institute of Aeronautics and Astronautics, 1981, p. 131-56. 17. D. J. Rose and R. K. Lister, Nuclear power, nuclear weapons and international stability, Scientific American, 238(4) (April, 1978), p. 45. 18. W. H. Menard, Toward a rational strategy for oil exploration, Scientific American, 244(1) (January, 1981), p. 55. 19. J. O'M. Bockris, Economics, living standards and energy policy, International Journal of Hydrogen Energy, 9(4) (1984), p. 263-7. 20. H. M. Agnew, Gas-cooled nuclear power reactors, Scientific American, 244(6) (June, 1981), p. 55. 21. L. O. Williams, Hydrogen Power, Pergamon Press Inc., 1980. 22. R. W. Conn, The engineering of magnetic fusion reactors, Scientific American, 249(4)(October, 1983), p. 60. 23. J. P. Holdren, Fusion energy in context: its fitness for the long term, Science, 200 (April 14, 1978), p. 168. 24. R. F. Post, Nuclear fusion by magnetic confinement, Astronautics and Aeronautics, 11(8) (August, 1973), p. 50. 25. D. P. Gregory, The hydrogen economy, Scientific American, 228(1) (January, 1973), p. 13.
Energy in Transition*
Laurence O. Williamst Martin Marietta Orlando Aerospace, Box 5837, Orlando, Florida, 32855 (USA)
S UMMA R Y A plentijul, benign energy supply is essentialjor a high standard of living. In the near future the current temporary oil surplus will be exhausted and we will experience energy shortages and increasing prices. The surplus is not the result of the discovery of significant new oil. Its cause is a ponderous supply system feeding oil to a world economy with reduced demand resulting from successful conservation and recession. The surplus has depressed research and development, reducing our ability to respond to future shortages and rising prices. Decreasing or eliminating the combustion of Jossil fuel materials as energy sources will be very beneficial for the long-term fossil fuel materials are very valuable as chemicalsJ~,edstocks. Combustion offossil ,fuels is the source of most air pollution and acid rain. Carbon dioxide placed irreversibly in the atmosphere may cause dramatic shifts in climate and higher sea levels. New ideasfor energy sources and systems are needed. Expanded use of coal and shale oil will increase environmental damage. Fission nuclear energy has promise but has difficulties that nearly paralyze the industry. Fusion languishes from lack of research funds. Renewable energy systems have not shown much promise for large-scale use. New energy systems will require years to develop and implement. The cost will be high anda great deal of energy will be required. The technical community should exert leadership to implement this work now, while low cost energy remains available and the economy is relatively strong. * The opinions expressed in this article are those of the author and do not represent the official position of Martin Marietta Orlando Aerospace. t Present address: 4915 Caspian Court, Orlando, Florida 32819, USA. 171
Applied Energy 0306-2619/86/$03-50 ~' Elsevier Applied Science Publishers Ltd, England, 1986, Printed in Great Britain
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Laurence O. Williams A system with fusion as the prime energy source, and hydrogen as the storage and distribution medium, is suggested as a potential candidate system to supply benign plentiful energy for the future.
THE P R O B L E M S A high standard of living requires a clean, healthy environment and largescale per capita use of energy and raw materials. The need for a clean, healthy environment is self evident. The need for energy and raw materials is demonstrated both by the logic that energy and raw materials amplify an individual's ability to accomplish tasks with increased productivity and by the examination of the relationship between per capita energy use and per capita gross national product of the nations, as shown in Fig. 1. This Figure indicates that nations using the most energy tend to have the highest standard of living. A group of economists has performed analyses that indicate, essentially, that all improvements in productivity and living standards are a direct function of the amount of energy used. In their analyses the term Energy Return On Investment (EROI) is used to describe the economic impact of a particular energy form on productivity and living standards. Energy sources with a high EROI increase productivity and living standards more than sources with a low EROI. Of the c o m m o n fuels, natural gas has the highest EROI, petroleum is a close second and coal has the lowest. Derived energy forms, such as electricity, have higher EROI's than the source fuels. As a result, it is economically advantageous to use many energy units of a low EROI fuel, such as coal, to make a smaller number of energy units of a high EROI energy form, such as electricity. Not all economists agree that this approach is valid, but the strength of the correlations obtained indicates that energy has a profound impact on the economy. They also show that much current economic analysis does not give proper attention to the effects of energy supplies and cost on the growth of the world economy. 1'2 To improve, or even maintain, world-wide living standards, strong efforts must be made to implement an energy strategy that will ensure high EROI, environmentally benign, bountiful energy sources for the future. In this paper a synoptic analysis of our near term energy situation will be presented: this analysis indicates that there will be severe problems involving supplies and environmental degradation after 1995. A potential energy system solution for these problems is outlined.
Energy in transition
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In 1977 three energy sources provided the bulk of the energy used in the United States: 3 fossil fuels, 91.5 per cent; nuclear energy, 4.5 per cent and hydro-electricity, 3.9 per cent. A roughly similar breakdown of sources is true for all industrialized nations, with fossil fuel combustion supplying over 90 per cent of the energy. The most desirable fossil-fuel sources will be exhausted within the lifetimes of more than half the people living today. Once the fossil-fuel reserves are consumed it will take millions of years for the natural formation processes to replace them. Their depletion will not only cause energy shortage problems, but the chemicals found in fossil fuels have a broad spectrum of alternate higher value uses and are nearly irreplaceable in these applications. In addition, their extraction and combustion are harmful to the environment. Thus far it has been difficult, or impossible, to attach appropriate monetary values for the environmental harm to the costs of the fuels. As a result, the current price of fuel paid by users is significantly less than the actual cost to world society. Irrespective of our. current dependency, the future higher value uses, and the present and future environmental damage caused by fossil fuel, it will be necessary to find replacement energy sources in the near future. Proven world oil reserves are estimated to be 640 billion barrels 4 and current world consumption is about 22 billion barrels per year. 5 Thus, at present rates, proven world reserves will be exhausted in about 30 years. If consumption increases at 2 per cent per year, the time to exhaustion will be 20 years. If the developing nations achieve their goals for improvements in living standards, their expanded use of oil will cause fuel consumption t o increase at rates higher than 2 per cent and exhaustion will occur even sooner. More oil may be found, but the evidence indicates that greater effort will be required to find each new smaller oil field, and the EROI of these fields will continue to decrease. The oil found will extend the time to exhaustion by no more than a few years. 7 The chemicals present in the fossil fuels are of extreme value in the production of a long list of materials useful or necessary for modern civilization. This list includes plastics, rubber, synthetic textiles, paint, drugs, lubricants and agricultural chemicals. Each May the American Chemical Society publishes a list of the 50 chemicals produced in the largest quantities in the United States. For 1984 the total production of organic chemicals, made largely from fossil-fuel chemicals, was 168.99 billion pounds weight. The largest production of a fossil-fuel chemical was recorded for ethylene (fifth overall) at 31.18 billion pounds. Ammonia, ammonium nitrate, a m m o n i u m sulfate and urea are produced
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from hydrogen derived from fossil fuels. Their production level of 64.85 billion pounds can be added to the fossil-fuel derived chemical products. Twenty-eight of the top fifty are chemicals from fossil fuels: four are made from hydrogen derived from fossil fuels. 6 While it is possible theoretically to make these chemicals from other sources of carbon, i.e. shale oil, wood, straw, or other plant-derived feedstocks or even the carbon dioxide from the air, the cost would be very high. Our combustion of the planet's easily recovered hydrocarbon resources for fuel will condemn future generations to obtain petroleumbased chemicals from other sources at much higher costs, or to do without. 7,8 A large portion of environmental pollution is the result of extraction and use of fossil fuels. The sequence of environmental damage begins with the recovery of the fuels from their natural deposits. 9 The soil in the vicinity of coal mines or oil wells becomes contaminated with fuel residues and the minerals associated with the fuels. All fossil fuels contain sulfur, and low levels of many other toxic elements such as selenium, arsenic and beryllium. Oxidation of the sulfur leads to acid mine drainage. Selenium, beryllium and similar toxic elements are leached into the acidic waters. In the vicinity of the deposits, this pollution is often so extreme that no use of the land is possible for many years after the fuel recovery is completed. Away from the source, the acid mine drainage can poison streams, rivers and lakes as the toxic contaminants are carried to the sea. Subsidence of the ground, as a result of fossil fuel recovery, is a worldwide problem. In Texas and California the pumping of oil has caused the ground to subside, changing the course of rivers and allowing the sea shore to move inland. 1o Oil pumping has also allowed the intrusion of salt water into previously fresh water wells, so preventing their use for drinking water or irrigation. In the eastern states such as Pennsylvania the cavities left by coal mines are collapsing (and occasionally burning), so destroying farm land and towns. Ordinary air pollution (smog) is largely the immediate result of the combustion of fossil fuels for energy. Smog is caused by complex chemical interactions of partly-burned fossil-fuel chemicals reacting with one another, and the oxygen and ozone in the air. These reactions are enhanced by the ultraviolet radiation from the sun. Smog causes health problems, damage to plants and structural damage to buildings. The costs of smog damage are difficult to ascertain because they are diffuse and difficult to separate from other forms of ageing and weathering. Even when some definition is possible, it is difficult to assess costs because they
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cannot be traced to any single source. Total smog damage costs are estimated to be quite high but they are borne by the public at large with little clear knowledge of their magnitude, a Acid rain is caused by sulfur dioxide produced by the oxidation of sulfur in the fossil fuels and the nitrogen oxides that are a product of all high-temperature combustion processes that use air. The sulfur dioxide and nitrogen oxides react with the water and oxygen in the air to produce sulfuric and nitric acids, respectively. The effects of acid rain are even less understood than the effects of smog. It has been implicated in the death of trees and the sterilization of lakes in both the United States and Europe. The acid rain directly damages foliage, it leaches nutrients from the soil and it mobilizes minerals such as aluminum in a water-soluble form. Once in solution, the mobilized minerals can be taken up by plants with adverse effects. They can drain into lakes and rivers where they have toxic effects on the aquatic life. The severity of acid rain effects appears to be regional. In parts of the country where the soil has high acid buffer capacity, the effects are limited to direct damage to foliage. Where soil has little buffer capacity, such as in the north-eastern United States, eastern Canada, central Europe and the Scandinavian countries, the acid rain effects may be acute today. 1~ Smog and acid rain products have a relatively short lifetime in the atmosphere.a a The chemicals responsible for the pollution are relatively soluble in water and rainfall removes them rapidly from the air. The reason that they have become a problem is that we continue to produce them at a very high rate. If the burning of fossil fuels is stopped, these pollutants would be cleared from the atmosphere in a time as short as a few months. The type of fossil-fuel air pollution least understood, but possibly the most damaging in the long run, is the essential irreversible addition of carbon dioxide to the atmosphere.12 About half of the fossil carbon dioxide produced is absorbed in the surface layers of the ocean; the rest remains in the atmosphere. It is known with good accuracy that the atmospheric concentration has increased from 295 parts per million prior to 1900 to a value of 340 parts per million today, a 15 per cent increase. 12,13 The portion that is absorbed in the ocean causes a change in acidity and in the ratio of carbonate to bicarbonate ions. This change will interfere with the ability of animals to deposit carbonate shells, with the potential of causing mass extinction.14 Carbon dioxide, which is not absorbed by the oceans, changes
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atmospheric thermal properties in a way that results in trapping more heat on the surface of the earth. How strongly increased carbon dioxide will influence the earth's heat balance is not well understood, but it is estimated that if energy generation continues to rely heavily on the combustion of fossil fuels, first using up the oil then shifting to coal, the carbon dioxide level will double by AD 2040. This doubling will increase the average global temperature by 3 to 5°C with the largest increase occurring at the poles where the increase may be as much as 20 °C. Initially, the temperature increase may only cause instability and shifts in the weather patterns, but eventually it will result in the warming of the earth's surface and the melting of polar ice.13 When this occurs, some time in the future, the sea level will rise, inundating coastal areas. If the long-term heating of the earth continues to the point at which all the ice melts, the sea level will rise hundreds of feet, thereby inundating much of the land currently occupied by mankind. 13 Coal is suggested as a substitute energy source, when petroleum depletion becomes critical. Unfortunately, coal has the lowest EROI of the fossil fuels. 1 Coal mining is very dangerous to the miners, its extraction is probably the most damaging to the land, its use introduces the largest quantity of sulfur and other toxic elements into the environment and, of all the fossil fuels, it produces the most carbon dioxide per unit energy developed. From the standpoint of the long-term health of the world, an argument that we should have avoided the use of fossil fuels for energy generation seems easy to justify, given their higher value use and the environmental damage that they cause. Our great dependence on them came about because of the ease of obtaining them, the relative simplicity of the technology required for their use and our lack of regard for their future higher value uses and knowledge of the long-term environmental effects. Because we lack the ability to properly determine future value and the knowledge to evaluate the cost of future environmental damage the near term EROI is high and their use has increased our contemporary standard of living. 1,2 Over the next 25 years, to replace petroleum fuel by synthetics, whether derived from shale, coal, nuclear or renewable sources, will require an enormous capital investment, in the range of $10 trillion in present dollars. This equates to $400 billion per year in new plant investment if started now. If we wait l 5 years, the bill will more than double and severe disruptions in the world economy will be inevitable. The lead time
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necessary to design, build, test and place new energy system facilities in operation is sufficiently long that facilities needed 10 years from now should be initiated within the next few years. Compared with fossil fuels, nuclear energy sources present a similar supply picture, but a rather different set of pollution problems. The amount of energy available by the use of once-through nuclear cycles, as is current practice, is in the same general range as that available from the remaining oil. 3 The nuclear industry has a far better safety record for protecting its own personnel and the public than does the fossil-fuel industry, 9 but the reaction by-products, while currently controlled, are accumulating and must be dealt with soon in an entirely safe manner or they will make a pollution problem of the same magnitude as that from fossil fuels.15 Two disposal methods are available, internment in stable geological formations and space disposal,16 but there is little agreement as to which is best or how we should go about implementing either. Because of the short lifetime and waste-product problems with the oncethrough nuclear fission energy cycle, it is, at best, an interim solution to the long range need for a benign energy source. Development and large-scale use of the breeder reactor cycles, uranium 238/plutonium 239; or thorium 232/uranium 233, would greatly increase the total amount of energy available from the use of fission nuclear reactors, but at the cost of much larger quantities of radioactive waste. The breeder cycles would allow the use of fission nuclear energy for hundreds of years without depletion of necessary resources.3 For this to be a viable solution, a totally safe system of waste disposal must be developed and agreed to by all concerned. A second, non-technical, problem arises from the use of the fission reactor systems. Both burner and breeder systems produce used fuel elements that contain fissionable isotopes of plutonium mixed with elements from which it can be chemically separated--a far easier process than the separation of isotopes required to obtain fissionable materials from natural uranium. In the planned course of events, this material would be reprocessed to provide for refuelling current or new reactors, but, unfortunately, it can be used to make nuclear weapons. This route to weapons-grade fissionable material is technically simple and low cost, when compared with the process required when starting with natural uranium. 17 This problem exists with either once-through systems or with breeder reactors, but, because the breeder cycle depends on this material
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for refuelling, there is much more of it in the inventory and a greater opportunity for undesirable diversion for weapons use. Hydropower and geothermal energy sources appear similar when examined as potential long-term energy sources for the future. Both have the potential to supply energy for a very long time and are relatively benign to the environment. Unfortunately, for either to be of value, it requires an unusual juxtaposition of natural geological conditions. In the United States most of the good sites for harvesting these forms of energy have already been exploited. ~ At present, these sources supply less than 4 per cent of the nation's energy and the outlook for future meaningful growth appears bleak. As the result of research in the late 1970s, production of energy from renewable resources such as sunlight and wind is beginning. Solar energy is in use for the supplemental heating of buildings and has been used in demonstration projects for the thermal and photo-voltaic generation of electricity. Wind is producing modest amounts of electric power. A small pilot plant has demonstrated that energy can be extracted from ocean thermal gradients. These renewable sources will, in the future, make some contribution to the total energy supplies of the world. The energy concentrations of solar, wind and ocean thermal gradient sources are low and harvesting them may require huge structures using large amounts of raw materials. Recent studies indicate that, on detailed environmental analyses of the large material requirements, certain renewable energy sources may cause as much environmental harm as current energy systems. The large amounts of raw materials that must be processed take large amounts of energy. For many renewable systems, the time required to obtain a net gain in energy is very long. 9 The renewable energy sources are often available only at inconvenient places and may produce energy only intermittently. They may provide a valuable supplement to energy supplies, but it will be necessary to have a large capacity reliable source to supply the bulk of the required energy. All these factors indicate that we have a serious energy problem, yet during the last few years the funding for energy research and development has been decreasing. This trend is very dangerous, but understandable if the energy situation is examined with only a very short-term view, e.g. five years into the future. From 1979 to the present the short-term energy situation of the oil importing nations has improved. Three factors have contributed to this
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improvement; they are:
1. Conservation The oil-importing nations mounted strong conservation efforts in the wake of the oil embargo in 1974. These efforts have succeeded well beyond expectations and the use of oil has been reduced substantially. 2. Deregulation In the United States, deregulation of oil prices and partial deregulation of natural-gas prices resulted in an increase in exploration for gas and oil and greater recovery from existing fields. 3. New Oil Fields The discovery of significant new oil fields by Canada and Mexico has greatly increased their exportation of oil to the United States. This made it possible for the United States to reduce its competition with Europe and Japan for Middle East oil. These factors have reduced the probability of severe shortages in the short term. The Strategic Oil Reserves instigated by the Department of Energy in the United States, and similar activities by other oil-importing countries, will aid in weathering any short-term shortages. Nevertheless, in the longer term, 5 to 15 years in the future, the availability of sufficient energy to sustain our present standard of living is doubtful, a'v'ls The current combination of stable or decreasing oil prices and high interest rates is eroding our resolve and ability to take the steps that would avert dire future consequences. This combination of factors is very dangerous for the long-run health of free nations. As time passes, and we adjust to energy shortages and higher prices, our ability to respond to the threat gets weaker and weaker because it will take energy and capital to provide a solution to the problem.~9 Inappropriate action by environmental groups has exacerbated the problem. Their focused attack on nuclear energy 9 in particular, and upon technology in general, simply ignores the fact that there is no way that the world could support a 21st century population with 19th and 20th century technology. Our continued well being, including food and secure shelter, depends upon energy availability, s There are serious environmental problems with all of our current energy sources, but, for the most part, environmentalists' actions have discouraged nuclear research so that today's reactors are based on older technology. These actions by anti-technology environmentalists may have seriously impaired the
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employment of nuclear-energy resources that may, in fact, be intrinsically less of an environmental threat than the continued combustion of oil and coal. The reduction in the growth of nuclear energy has resulted in serious efforts to increase the use of coal, the most polluting of all fuels. It seems likely that an increased use of nuclear energy will be necessary during the future transition from dependence on fossil fuels. The factors that have resulted in the current easing of the energy problem are insidious. Our situation can be likened to a person with a serious life-threatening disease, whose symptoms have been alleviated by pain-killing drugs. The euphoria of the drugs makes it difficult to concentrate on the need for a cure. Time is running out for the industrialized world. If we plan properly we can minimize the need for drastic solutions to alleviate the problem. Without firm plans our reactions will be dictated by the exigencies of the time, and the ultimate outcome will be uncertain.19 The problems of energy supplies and environmental protection are in no way hopeless if action is started soon enough. An energy development scenario that can lead to a system with potential for abundant environmentally-benign energy for centuries will be described to illustrate the type of future energy planning that will be necessary for the solution of the problem.
A F U T U R E ENERGY-SUPPLY SYSTEM In the near future, up until 10 years from now, we need to greatly increase our exploitation of the once-through nuclear cycle and all possible renewable sources. It may be desirable to require the exploitation of the gas-cooled reactors to help alleviate some of the fears concerning a disastrous reactor accident, z° Increased renewable and nuclear energy use will help prevent growth in the use of the most polluting fuel, coal, and ease the pressure on petroleum resources used for chemical production. Growth in nuclear energy will require agreement on methods of disposal of nuclear waste. Unaerground disposal has the advantage that the materials are available if future use is found for them. 15 The difficulty with underground storage lies in the need to monitor the waste for a very long time, a time longer than recorded history, or to come up with a method of storage that ensures that there is no possible way that the waste can leak into the environment for this same long period of time. No
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method of accomplishing either of these goals has been suggested that satisfies all critics. Space disposal has the distinct advantage that the waste can be placed in an orbit where there is no chance of contact with the earth for millions of years. 16 Space disposal has some appealing characteristics, but little study has been performed. It is not clear how it would be done or if it is practical. Whichever waste disposal method is selected we need to get the necessary implementation underway soon. In conjunction with increased emphasis on renewable energy resources and fission nuclear-energy, effort should be made to implement the use of hydrogen as the general purpose energy carrier. The outputs from renewable and nuclear-energy sources do not match well in space or time with the needs of the users. This leads to the requirement for an energy storage medium that can be easily implemented. Nuclear and renewable sources are both non-portable, leading to the requirement for a portable energy-storage medium to serve the vital transportation sector of the economy. Hydrogen can be used as the medium for coupling the sources to the users. In this application, hydrogen serves the same r61e as electricity. Its advantages over electricity are: it can be easily stored near the production or user site to provide load matching and reliability, it can be used directly as a transportation fuel and it can be piped continental distances with low losses in pipelines that are out of sight under the ground. There are a number of potential fuels that can be made by the application of energy to their synthesis. Examples are: (1) synthetic petroleum, methane and alcohols manufactured by reacting coal with hydrogen produced from water, (2) ammonia manufactured by reacting nitrogen from the air with hydrogen from water, and hydrogen manufactured from water. An essential step in all these processes is the production of hydrogen from water. Because all require the manufacture of hydrogen, and hydrogen has a far lower environmental impact than any of the other possible synthetic fuels, the use of hydrogen directly is very practical. The use of hydrogen to produce synthetic gasoline from coal would only provide a new way to add carbon dioxide to the atmosphere. Over the last 15 years, research has indicated that there are no technological barriers to the use of hydrogen as a general-purpose fuel. Most fuel-using devices and processes can be converted to hydrogen and the environmental damage caused by its use appears to be orders of magnitude less than that produced by other fuels. 21 Along with the effort to implement hydrogen fuel use, it will be
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necessary to push the development of fusion energy production for the ultimate replacement of the fission nuclear cycle. By this approach, we can avoid the use of the breeder fission cycles, with their greater production of radioactive waste, and avoid the need to greatly increase coal burning. The planning intent will be that the large number of fission reactors needed in the near term will be the last generation of the devices. In the longer term, energy will be provided by fusion reactors and carried by hydrogen. Fusion nuclear energy offers the potential for an energy source that could meet the requirements of the future .22 The raw materials used in the production of fusion power, deuterium, lithium and boron, are available in quantities large enough that the depletion is not possible for hundreds of thousands of years. 23 The fusion reaction will produce approximately one-thousandth the waste produced by the once-through nuclear-fission power cycle and only one-millionth of that produced by a breeder reactor energy system. A fusion reactor will be struggling at all times just to keep operating. There is no combination of failures or sabotage that would cause a blow-up type of accident. The modest quantities of long half-life waste produced (activated reactor structures) can be disposed of by the methods used with the interim fission reactors. These considerations indicate that the fusion reactor will be able to provide a safe, long life base load energy system. There are no products present in the fusion reactor that can be diverted for the production of primary weapons. The lithium and tritium used within the reactor are the ingredients used in thermo-nuclear weapons. But to make a working bomb, a uranium or plutonium trigger bomb is required. It would be feasible to use the neutrons produced by the deuterium-tritium fusion cycle for breeding plutonium from uranium. This use of a fusion reactor for the production of weapons-grade plutonium is theoretically possible but it would be very complex and would not appear to offer an easier path to weapons than is currently available. Current experiments and theory indicate that, as the size of a fusion reactor is increased, it becomes more feasible and efficient. As a result, the first fusion reactors will be large facilities both in physical size and in energy production. 24 This is often seen as a barrier to near-term implementation of fusion technology. When coupled with a hydrogen energy distribution system, the large size is no problem and, in fact, may be an advantage.
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The large fusion reactors can be located near, or floating on, the sea so that cold deep sea water can be used for cooling. The heat exchange system will be controlled in such a manner that the output cooling water will be rejected at the local surface temperature of the ocean. This will prevent ocean thermal pollution. In some locations, it may be advantageous to use a significant portion of the waste heat to desalinate sea water to add to potable water supplies. Some of the electrical power will be used in the vicinity of the reactor, but a large part of it will be used to electrolyze water for the production of hydrogen and by-product oxygen. Hydrogen will be used as the energy storage medium to match the unvarying output from the reactor to the variable demand, to serve as the storage and transmission medium and as the transportation fuel. The ease of transmitting a gaseous fuel, hydrogen, across continental distances will allow the construction of very large facilities and reap the maximum economies of scale. Many of the existing natural gas pipelines can be used, with relatively minor modifications, to carry the hydrogen. The by-product oxygen can be used in all current applications, but there will be far more available than is required. When polluted water is treated with pure oxygen the rate of purification is greatly enhanced. Some of the excess oxygen can be used for oxygen enhanced waste water treatment and to improve the quality of rivers and lakes. Any excess not used for specific industrial or environmental purposes can be vented to the air without any harm to the environment. The energy from the reactor is stored in the hydrogen produced by the splitting of water. When, at a later time, the hydrogen is burned the energy is recovered. The amount of hydrogen and oxygen produced by the reactor is exactly balanced by the hydrogen and oxygen used when the hydrogen is burned to recover the energy. As a result of this exact match there is no net addition of matter (such as carbon dioxide) to the environment by this energy system. The basic scientific knowledge is available for the production of fusion energy 22-24 and the adoption of hydrogen as the storable energy carrier. 21 Implementation of such a system would put an end to energy shortages and would stop the pollution that results from the use of energy. There is, however, a large amount of applied engineering research that must be performed and a number of barriers to overcome, before this system can provide energy routinely. The most difficult problem to overcome in the application of this or any solution to the energy dilemma is the enormous capital investment in the
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current fossil-energy systems. The replacement of these systems with new systems that the world can live with, for a long period, will require an equally enormous investment. This is, in fact, the most difficult problem we face, but we know that the current systems must be replaced eventually and the longer we wait, the higher the cost and the more difficult the solution will be to implement. Our procrastination will simply make the change even more difficult, when it is forced upon us by shortages of fuel and increased environmental degradation.19 This or any other solution will be met with all the c o m m o n challenges posed in an effort to resist change. These challenges will take the form of questions and statements such as: 'How extreme is the carbon dioxide problem?', 'Carbon dioxide will not effect us for a number of years', ~Fusion may not be feasible', 'Hydrogen is dangerous', and 'The current systems can be cleaned up'. These questions avoid the central issue that action is needed n o w . If, for example, we spend the next 10 to 15 years studying the carbon dioxide problem and find that we should have stopped adding it to the atmosphere today, we may be content with the scientific validity of the answer, but find that it is too late to save us from severe thermal pollution of the planet. Today, the feasibility of the fusion hydrogen energy system is similar to the feasibility of travel to the moon in 1960. In 1960 no one could provide the blue-prints for a moon rocket, but the essential principles were clear. With the proper attention to detail and a lot of hard work an 'Apollo' was built and it carried men to the moon. The essential principles of a fusion reactor and hydrogen utilization are clear. With the same approach the system can be built and it will provide energy. As it is enlarged, it will work better and cost less. By the time we are using the fusion hydrogen system for a tenth of our energy supply, the technology will be well in hand and we will be on the way to ending many forms of pollution and preserving the fossil fuel chemicals remaining for higher value use. There is no guarantee as to the cost of the energy but, when weighed against rising EROI of tbssil fuels and the enormous, but difficult-to-quantify cost of planetary pollution, the cost will be acceptable. If we spend the next 10 years quibbling over the details of a plan and performing expensive studies, we will waste both time and money to achieve a detailed description of the problem, but be no closer to a solution. This energy system, using whatever renewable energy can be harvested and with base load nuclear fusion reactors, will have a very long life. It will be able to supply the very large needs of the planetary population with
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minimal environmental damage. 25 It will be very high technology and the development will be a massive undertaking. The management, and research and development techniques, developed for programs such as 'Apollo' would seem to be the best method available for the implementation of this plan. It is the near-term responsibility of the technical c o m m u n i t y to provide the leadership to select a course of action that has a high probability of success and push hard for its implementation. Each day that passes without action makes the ultimate solution to the problem more difficult and costly. If we and our children are to survive in a clean, prosperous world, we must get started on our new energy system immediately.
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l 6. S. G. Rosen, Nuclear waste disposal in space. In: Macro engineering: The rich potential (R. Salkeld, F. P. Davidson and C. L. Meador, (Eds)), The American Institute of Aeronautics and Astronautics, 1981, p. 131-56. 17. D. J. Rose and R. K. Lister, Nuclear power, nuclear weapons and international stability, Scientific American, 238(4) (April, 1978), p. 45. 18. W. H. Menard, Toward a rational strategy for oil exploration, Scientific American, 244(1) (January, 1981), p. 55. 19. J. O'M. Bockris, Economics, living standards and energy policy, International Journal of Hydrogen Energy, 9(4) (1984), p. 263-7. 20. H. M. Agnew, Gas-cooled nuclear power reactors, Scientific American, 244(6) (June, 1981), p. 55. 21. L. O. Williams, Hydrogen Power, Pergamon Press Inc., 1980. 22. R. W. Conn, The engineering of magnetic fusion reactors, Scientific American, 249(4)(October, 1983), p. 60. 23. J. P. Holdren, Fusion energy in context: its fitness for the long term, Science, 200 (April 14, 1978), p. 168. 24. R. F. Post, Nuclear fusion by magnetic confinement, Astronautics and Aeronautics, 11(8) (August, 1973), p. 50. 25. D. P. Gregory, The hydrogen economy, Scientific American, 228(1) (January, 1973), p. 13.