Develop Environmental Options for the Energy System
All aspects of the national and international system for the exploration, transportation, production, distribution, and use of energy have effects on environmental conditions. Thus both the supply of and the demand for energy must be discussed when exploring more environmentally sensitive options for the energy system. The future development of the energy system and the technologies and sources of energy that will be used, will determine the extent to which the system will be compatible with the environment.
Energy is crucial to the transformation of materials and essential to improving standards of living throughout the world. Energy is also a major driver in shaping the quality of the environment. On the one hand, energy creates environmental problems in its extraction, transportation, combustion, storage, and final consumption. Environmental problems are caused by activities as diverse as strip mining, oil spills, and nuclear-waste disposal. On the other hand, the wealth generated by economic returns allows a society greater economic opportunity to address environmental problems.
Energy's value to society is in the services that it provides: heating and cooling buildings, transporting people and goods, driving industrial processes, and powering the electronic information explosion. These services are created by capital and operating investments made both in energy and in the end use. For example, the costs of heating, cooling, and lighting a commercial building encompass investments made by both the electrical utility and the building owner. The latter's investments include insulation, computer-driven climate control, and high-efficiency lighting. The total efficiency of the energy system is a function of energy prices, overall economic performance, and technology development.
The one constant in energy prediction is surprise. At one time, energy experts
Science and technology can contribute to the goal of clean air by developing technologies that reduce the cost of pollution control, so that we get cleaner air for our investment in pollution control than we do with existing technologies. These technologies might be
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believed that energy and gross national product (GNP) were inextricably intertwined; today, we know that they can be uncoupled. At one time, most experts expected that oil prices would be two to three times higher than they actually are today. In recent years, energy systems have increased in efficiency and the supply of natural gas has been greater than projected.
THE ENERGY SYSTEM AND ITS ENVIRONMENTAL EFFECTS
The environmental effects of energy production and use occur on local, regional, and global scales. At local levels, energy production and use in autos, power plants, and industry are among the principal causes of urban air pollution, from particles to CO2 to tropospheric O3. Scientific understanding of the causes and developments of technologies have resulted in much-cleaner urban air.1 Scientific understanding of the behavior of automobile emissions in the presence of sunlight illustrate the key roles of research and development in addressing environmental problems.
A particularly important part of the energy system at the local level is energy efficiency. A number of utility companies have initiated programs to improve the efficiency with which energy is used by residences, business, and industry. A number of technological advances in lighting, heating, cooling, and passive energy activities have also made it possible to keep energy demand constant without sacrificing lifestyle advances. In the case of transportation, automobile fuel economy has increased from 14.2 miles per gallon (mpg) in 1973 to 28.2 mpg in 1992—all through technological advances.
On the regional scale, energy production and use are the major factors in acid deposition. SOx and NOx emissions from power plants and NOx emissions from automobiles are major contributors to acid deposition. Acid effects on aquatic
and forest ecosystems are of concern. Large-scale government and private investments in understanding this problem have helped to secure the passage of legislation that will have a substantial beneficial effect on the reduction of emissions that cause acid rain.
On the global scale, although great uncertainties remain with regard to the timing, geographic distribution, and magnitude of climate change, the Intergovernmental Panel on Climate Change (IPCC) has concluded that climate warming would result largely from the emission of CO2 in the combustion of fossil fuels. The climate-change problem is inherently international because of CO2 and the effects of climate change are globally distributed. For example, an international treaty on climate change has been agreed to by many nations of the world, and declarations of national intent to reduce emissions of greenhouse gasses to 1990 magnitudes are in place. It remains an open question as to whether national actions to bring about such reductions are feasible and will occur. In any case, such reductions would only postpone the projected climate change by a few years. Studies by the IPCC have shown that much deeper reductions—around 60–80%—in CO2 emissions will be necessary, according to computer models, to stabilize CO2 at current concentrations in the atmosphere.
Even the most basic uses of energy can have severe environmental effects, especially on ecosystems in developing countries. A good example is the use of wood as an energy source in developing countries. The harvesting of wood has destroyed ecosystems and led to serious soil erosion. With developing countries dramatically increasing their energy use, energy supplies could be increasingly dependent on fossil fuels in the future and that could increase the net contribution to CO2 production.
One effect of energy production that has been most difficult to solve stems from the use of nuclear fission as a source of energy. Nuclear power has negative and positive environmental impacts as a replacement for large coal-and oil-burning
Environmental problems touch all aspects of human existence. It is inappropriate to develop a simple laundry list of "one-size-fits-all" goals. We need, instead, to think in terms of broad themes. These include (1) mitigation of harm associated with residuals (air and water emissions and soil contaminants), (2) encouragement of increasingly efficient resource use, and (3) protection of ecosystems and wildlife. Which specific emissions should be targeted and which ecosystems deserve focus should be determined locally or regionally in most instances because most environmental impacts are local, not regional or national. Establishing a national laundry list of top priorities in specific is both a static approach and one that fails to take into account the degree to which many environmental problems are fundamentally local; priorities will vary by locality. This requires local flexibility in determining goals and priorities.
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plants. Use of nuclear power substantially reduces air pollution because nuclear power plants do not emit NOx, SOx, or particles. However, there is concern about the potential for accidents releasing the radioactive products of nuclear fission (from plant operations, transportation, or storage) as well as the disposal of nuclear wastes. The latter remains the largest environmental problem associated with nuclear power. The environmental aspects of the disposal of radioactive wastes from nuclear power plants remain a divisive issue in society. Legislation has been proposed for the disposal of such wastes. A site has been identified and other possible locations for repositories have been suggested. Billions of dollars have been spent, billions more will be spent, but the problem remains unsolved because of both scientific and political factors. The safe disposal of radioactive waste and the ability to demonstrate its safety in a way that commands credibility with the general public will determine the possibilities of further expansion and use of nuclear power systems in the United States.
Those are but a few examples of the ubiquitous adverse effects of energy production, distribution, and use. The environmental effects, however, are broad. The use of every energy source is part of a general fuel cycle. Environmental impacts are associated with resource extraction, fuel refining, storage, transportation, conversion, and end use.
ENERGY AND THE FUTURE
Energy is the key to physical transformations of the material world. A supply of plentiful energy is the key to an economic system that we can control to be environmentally benign, provided that the energy system itself is not the overwhelming source of the environmental problems. There is a key link between environmental impacts and the energy demands of people. Our ability to devise systems of transportation, agriculture, manufacture, and housing that use less energy will have pronounced effects on our environmental future.
Our ability to choose and control production processes, to purify wastes and remediate waste sites, to clean and move water, to extract minerals, and to perform all the other activities of human systems depends directly on the availability and cost of energy. At the same time, environmental responsibility increases, comparative energy costs for a new technology become lower, new possibilities for all human activities become available; the menu of alternatives from which we can draw expands. Expanding the availability of energy that is renewable, and thus indefinitely sustainable, that is not itself automatically a source of potential global warming, and that is not itself a source of uncontrollable polluting waste is one key to providing technological alternatives for sustainable human activity.
The nation's environmental goals for the future should be sustainable development across full spectrum of human activity.
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The key to achieving environmental goals is technology. It is important to emphasize that in the environmental arena, the application of technology and the introduction of products and processes into the commercial arena are essential. Development of new knowledge is important, but doing something with it is essential. It is critical to include both science and application, public and private sectors, and especially the governments of all industrialized nations in developing technology to address environmental concerns.
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Some have indicated that there is an important caution in moving toward a renewable-energy future. Both energy consumption and pollution could be associated with the deployment of the capital infrastructure needed to capture and distribute renewable energy. Any energy source has a capital cost per unit of energy service provided (even if the fuel is ''free"). That implies potential environmental impacts associated with putting the capital structure in place and needs to be included in any analysis of this topic.
ENERGY SCIENCE AND TECHNOLOGY DIRECTIONS
The present federal and private investment in energy research and development (R&D) is large. Many aspects of the energy system are under investigation and development. Environmentally more benign modes of coal, oil, and gas extraction and exploration are under development. Extensive research and development regarding renewable sources of energy are being conducted by both public and private institutions. More efficient electric-power production is a major R&D thrust of the electric utility industry.
The efficiency of the energy system on both the supply and the demand sides is under continuous improvement through investments in R&D and implementation of the results through timely investment in physical capital. Historically, the energy efficiency of the economy has systematically improved since the beginning of this century in terms of energy use per unit of gross domestic product (GDP), but not sufficiently to offset the growth of GNP even on a per capita basis.
The most environmentally troublesome aspect of the operation of the present energy system is its use of fossil fuels, which are today available at attractive market prices. Fossil-fuel use is at the core of many environmental problems, including urban air pollution, acid rain, ecological impacts of resource extraction, and global warming. The environmental externalities resulting from the use of fossil fuels, some of which were described above, could be greatly reduced if these externalities were properly incorporated into energy-pricing mechanisms. The important directions for long-term energy R&D will be those which will "defossilize" the energy system. During the course of the next several decades,
less carbon-intensive fuels are likely to become essential components of the fuel supply. Natural gas can become the transition fuel to a less fossil-fuel-based economy. Worldwide defossilization will require much greater emphasis on three major R&D directions: (1) renewable energy sources, (2) energy efficiency and conservation, and (3) safe, publicly acceptable nuclear power.
Progress is being made in increasing the efficiency and reliability 2 of some forms of renewable energy resources. For example, the efficiency of photovoltaic cells has been continuously improving. Biotechnology could play a continuing role in increasing our ability to use biomass as a source of energy. In addition, improvements have been made in the cost and reliability of wind-generated power in areas suitable for this source.
Coal is the most abundant fossil fuel in the United States and many other countries. Despite its liabilities with respect to its impact on the environment, it is still and will probably continue to be the fuel of choice for electricity generation because of its low cost and abundance.
Efforts continue to be made to improve the efficiency of coal combustion and energy conversion. Although the average efficiency of all coal-fired power plants is around 33%, there are hopes of increasing it to 40% or more. Already, some plants are achieving 43% efficiency, and new generations of "clean-coal technologies" are expected to deliver efficiencies of 40–45% at costs comparable with those of conventional coal plants (NRC 1995a). In addition to improved plant maintenance and operation, some promising technologies are the integrated gasification combined cycle (IGCC) and the pressurized fluidized-bed combustion system (PFBC).
The use of nuclear fission is now almost 50 years old. The acceptability of nuclear power has varied from nation to nation and has varied with time. Nuclear power in the United States faces formidable obstacles that are primarily social and economic. Fear of nuclear accidents and difficulties with waste disposal have resulted in social pressures that prevent siting of nuclear power plants. Regulations
and other requirements have contributed to increased costs of construction. To keep nuclear power as an open option, research focused on removing these obstacles should be maintained. A continuing R&D goal should be the development of innovative, safe, publicly acceptable nuclear power systems. A previous NRC (1992b) report entitled Nuclear Power: Technical and Institutional Options for the Future has addressed the problems facing U.S. commercial nuclear power and what would be necessary to keep open this option.
There is now more than 35 years of R&D experience on nuclear-fusion systems. Nuclear-fusion power installations hold the promise of easier waste handling and less radioactivity because no spent fuel is discharged from a fusion plant. The structural materials used in containing the plant become radioactive and might ultimately have to be safely disposed of, although the materials would, in general, be considered as low-level radioactive waste. Expectations have always exceeded achievements in this field, but nuclear-fusion power holds the potential for cleaner energy production. Were such a power source successfully achieved, at a cost comparable with that of current energy sources, many of the environmental consequences of the present energy system could be dramatically reduced.
The difficulties facing the development of commercial power production from fusion systems will require many decades to solve and will require international cooperation. There is no certainty that commercial fusion power can be achieved, but the value of such an achievement is likely to be so great that it is worth continuing to pursue it.
Two recent studies addressed the need to maintain a strong program in fusion research while recognizing that several large facilities could not be supported. The study by the President's Council on Science and Technology (PCAST 1995) recommended a fusion budget of $320 million for FY 1996 and canceling the planned Tokamak Physics Experiment (TPX) project. Congress appropriated $244 million. The congressionally requested study by the Fusion Energy Advisory Committee (FEAC 1996) recommended closing the Tokamak Fusion Test Reactor (TFTR) by 1998 and endorsed the recommendations of the NRC (NRC 1995c) report Plasma Science: From Fundamental Research to Technological Application, which recommended a strong experimental program to build the necessary scientific base for a long-term fusion program.
Improved efficiency in both the production and use of energy must be a consistent long-range R&D goal. We can reduce environmental consequences to the extent that we are able to reduce energy use through increased efficiency. For example, research on batteries and fuel cells for automotive propulsion and on magnetic levitation systems for trains is worthy of emphasis. However, it should be kept in mind that the theoretical maximum of efficiency remains much larger
than what has proved socially and economically practicable, given the highly dispersed and decentralized nature of the necessary investments and consumer decisions. The NRC (NRC 1990a) report Confronting Climate Change: Strategies for Energy Research and Development outlines a number of steps that can be taken to enhance our R&D effort in energy efficiency.
The federal government has taken a number of steps in this direction. Examples include the Partnership for a New Generation of Vehicles (PNGV), the Green Lights initiative to improve the efficiency of lighting, and the Clean Cities initiative.
Supporting Research and Development
The evolution of the energy system depends on R&D not only in the energy sciences and technologies previously cited, but also in many other fields such as materials for storage, energy carriers for distribution (e.g., hydrogen), and waste reduction. Some examples include R&D on materials that can make the storage, distribution, and use of energy more efficient. For example, high-temperature super conducting materials could improve energy storage. Especially important are the incentives and disincentives related to the use of environmentally advantageous energy forms. The effects of energy taxes and research on the economics of energy use warrant attention.
A very important R&D direction linked closely to the development of new energy sources is toward the use of hydrogen as an energy carrier. Prototype systems depending on a solar-energy/hydrogen-conversion cycle are in an experimental stage. The use of hydrogen as an energy carrier requires extensive R&D. If hydrogen turns out to be a feasible and economically sound mode of embodying and transporting energy, it can have a remarkable impact on the environmental consequences of energy use.
FINDINGS, CONCLUSION, AND RECOMMENDATIONS
Energy production and use underlie the growth of modern industrial society, but production and use are often replete with environmental problems. Of particular concern is the use of fossil fuels, which leads to environmental problems, such as urban air pollution, acid rain, resource extraction, and global warming.
Responses to those concerns can be actions on either the supply side (how energy is generated) or the demand side (how energy is used). In both cases, knowledge, technical, and social barriers need to be overcome before actions can be taken. These barriers can be steadily reduced by additional research and development.
Energy research and development should create options for an uncertain future of energy availability and the environmental impact of that energy. Development
of cleaner and economically viable efficiency and production alternatives will be key to preserving options against a number of contingencies. One contingency is scarcity caused by rising energy demand and limited supplies. Another contingency would arise from new knowledge indicating severe environmental effects from CO2 , radionuclides, or other emissions from conventional energy sources. If either of these contingencies arises, alternative energy sources and end-use technologies will be critical.
The nation's environmental goal should be a good balance between economic development and a clean, healthy environment.
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Energy research and development should create options for an uncertain future of energy availability and the environmental impact of that energy. Development of cleaner and economically viable efficiency and production alternatives will be key to preserving options against a number of contingencies. One contingency is scarcity caused by rising energy demand and limited supplies. Another contingency would arise from new knowledge that indicated severe environmental effects of CO2, radionuclides, or other emissions from conventional energy sources than is now expected. If either of these contingencies arises, alternative energy sources and end-use technologies will be critical.
The committee recommends sustained research and development that will lead to more options for energy generation and use, less emission of carbon into the atmosphere, and more efficient use of natural resources. In particular, the following topics should be explored
Electricity. Thus while the United States is still the largest national consumer of primary energy, its relative contribution to pollution from energy use in the world is declining. Per-capita electricity use remains strongly correlated with development as electricity continues to replace other forms of energy because of its environmental and other advantages. Further increases in electrification should be accompanied by research in non-fossil-fuel sources (described further below) load management, and in other conservation approaches.
Renewable energy sources. Solar energy, especially as used in photovoltaic cells, and biomass are the leading options for renewable energy sources. Research efforts should focus on making these more economical. Transition to widespread use will not occur until the cost of electricity from these sources is so low that large public-sector subsidies are no longer required to make them cost-competitive.
Coal. The United States, Russia, and China have vast reserves of coal. About 60 of U.S. electricity comes from coal plants. Coal is also a major energy source in other countries. Thus, even though efforts should be made to defossilize our energy sources, research and development to improve the efficiency and reduce the emissions of coal plants (clean-coal technology) can help the U.S. environment and be a major factor in the Asian market, where India and China will burn increasingly large amounts of coal.
Nuclear fission. A major source of U.S. electricity (21‰), nuclear plants do not emit carbon or other pollutants. However, the U.S. nuclear industry has been crippled by the high cost of plants, by the government's inability to solve the problem of safe and reliable disposal of nuclear waste, and by the resulting disenchantment of the public and investors. Nuclear research should focus on these problems and include designs with improved safety. Until such problems are solved, further expansion of installed nuclear power capacity is unlikely, at least in the United States.
Nuclear fusion. For more than 35 years, researchers in the United States, Russia (previously the Soviet Union), Japan, and the European Community have sought to use the energy potential of fusion to generate electricity. The potential fuel source is vast; yet the scientific and technological problems remain daunting. Although it might offer substantial advantages over fission plants in waste, fusion is unlikely to be a major energy source within the next 30 years. Basic and applied research should be continued.
Hydrogen. The committee recommends long-term R&D to investigate the feasibility of hydrogen energy cycles as a source of energy because of its potential as an efficient and clean carrier for the distribution of energy to users.
Transportation. The largest present primary source of energy in the United States is petroleum products; more than 50 of energy from petroleum products is used in transportation (DOE/EIA 1995). The ubiquitous automobile influences our choice of jobs, where we live, and how we spend our leisure time. There has been enormous progress (including improvements in fuel efficiency) in the reduction of automobile emissions implicated in urban air pollution; but the automobile is still the major source of such pollution in part because growth in automobile ownership and in driving per vehicle has nearly offset this progress. Continued research to improve the fuel efficiency of automobiles will help, but further major improvements will almost certainly require switching from vehicles powered by the internal-combustion engine to electric (or possibly hybrid-electric) or hydrogen-fueled cars that need such technologies as fuel cells, flywheels, and greatly improved batteries. Research is needed if that transition is to occur.
The United States should continue to address ways of making energy use more efficient, including pollution reduction. It should also help to conduct the R&D and policy analysis required to take account of the severe needs of the developing world, where primary energy use for economic development is less
efficient, the growth in primary energy consumption is more rapid, and severe environmental damage per unit of energy is much greater than in developed countries. This will persist until better methods of energy use are developed and political and economic incentives for achieving their adoption sufficiently rapidly on a large enough scale can be devised.
For more information and guidance, the reader should refer to the following:
NRC (National Research Council), Confronting Climate Change: Strategies for Energy Research and Development (Washington, D.C.: National Academy Press, 1990).
NRC (National Research Council), Automotive Fuel Economy: How Far Can We Go? (Washington, D.C.: National Academy Press, 1992).
NRC (National Research Council), Review of the Research Program of the Partnership for a New Generation of Vehicles (Washington, D.C.: National Academy Press, 1994).
NRC (National Research Council), Coal: Energy for the Future (Washington, D.C.: National Academy Press, 1995).
NRC (National Research Council), Plasma Science: From Fundamental Research to Technological Application (Washington D.C.: National Academy Press, 1995).
NRC (National Research Council), Nuclear Wastes: Technologies for Separations and Transmutation (Washington, D.C.: National Academy Press, 1996).