Energy Technologies




Energy Technologies

█ LARRY GILMAN

Energy technologies are techniques for moving energy from a source to a point of use, for transforming it from an original source-form to an end-use form, or both. They are often lumped into two groups, conventional and alternative. Conventional energy technologies derive energy from fuels, either fossil (coal, oil, natural gas) or nuclear (uranium, plutonium). These technologies first turn the energy latent in fuel into heat, then transform some percentage of that heat into another, more useful form of energy (or apply the heat directly, as to warming a building, smelting ore, or the like). Approximately 90% of present-day energy use is provided by conventional sources.

Alternative energy technologies, in contrast, harvest energy from renewable, natural flows rather than from fuels. Technologies that collect energy from sunlight, wind, wave action, or plants are considered alternative energy technologies. (An exception to the alternative/conventional classification scheme is hydroelectric power, the generation of electricity from water flowing downhill. Hydroelectric power, although it harvests an energy flux from the environment rather than burning a fuel, is usually considered conventional because it has been utilized on an industrial scale for so long.)

Many energy technologies, conventional and alternative, produce electricity. Electricity is a uniquely useful form of energy, not a source of energy. Thus, the belief that an electric-powered device such as an electric car is "clean" is only correct when the electricity that it uses is produced cleanly. Most electricity is produced by coal-burning power plants or nuclear power plants; the former involves environmentally destructive mining and air pollution, while the latter involves some environmentally destructive mining and produces growing inventories of radioactive material that might be released to the environment either accidentally or deliberately, as by wartime or terrorist action. Therefore, there is nothing intrinsically "clean" about electricity. About 51% of United States electricity is currently produced by coal-burning power plants, 21% by nuclear power plants, 17% by natural-gasfired power plants, 6% from hydroelectric dams, 3% from oil-fired power plants, and 2% from wind, wood, and photovoltaics.

Several national-security issues arise with respect to energy technologies:

  1. Self-sufficiency. An energy source that must be imported, such as oil, is vulnerable to cutoff by hostile parties. This was demonstrated by the oil crisis of 1973, when the Organization of Oil Producing Countries (OPEC) suddenly quadrupled its oil prices from about $3 to about $13 per barrel (1 barrel = 42 United States gallons or 159 L) in retaliation for United States support of Israel. This triggered an economic crisis in the United States and elsewhere. In contrast, the United States has large domestic stocks of coal and uranium, and is not vulnerable to a cutoff of these energy sources; nor is it entangled politically or militarily with foreign sources of these fuels, as is the case with oil. (However, coal and uranium produce electricity, which, unlike oil, does not yet run affordable cars; therefore, coal and uranium cannot, at present, significantly decrease United States dependence on foreign oil.) Renewable or alternative energy resources also have the advantage that they are not imported.
  2. Fragility. Energy sources that can be disrupted at central points or along key transmission routes are more vulnerable to terrorism and war than distributed energy sources. For example, much of the United States electrical grid—a tuned, interdependent, dynamic network—could be blacked out for days or weeks by the destruction of relatively few switching points, control centers, or transmission lines. Locally-harvested alternative-energy sources such as rooftop photovoltaics or woodlots are immune to large-scale disruption, but cannot serve all purposes; rooftop photovoltaics are still expensive relative to grid electricity, and there are no wood-burning computers or refrigerators. Between the resilience of locally-produced energy supplies and the brittleness of the coal- and nuclear-fueled electrical grid lie the energy systems that rely on distributed stocks of fuels such as gasoline and natural gas. Although these energy technologies still rely on a few centralized refineries or long-distance pipelines, they are tolerant of temporary or local damage.
  3. Hazardousness. Some energy sources are hazardous due to toxicity or explosive potential. Standard nuclear power plants cannot explode, but they do contain large inventories of radionuclides that could be deliberately released by an enemy; after the terrorist attacks of September 11, 2001, the United States Nuclear Regulatory Commission ordered immediate, drastic increases in security for nuclear power plants. A less well-known source of vulnerability is liquefied natural gas, which is imported to the United States in large tanker ships and stored in centralized tank farms for national distribution via long-distance pipelines.
  4. Pollution. Pollution or greenhouse-gas emissions that harm a country's citizens, environment, and economy can be thought of as a danger to national security. All sources of energy, including wind and solar, require the extraction and refinement of metals and other substances, some toxic; conventional sources further require the extraction and (often) refinement of fuels and either (a) release combustion products to the atmosphere or (b) require the near-perfect, near-perpetual containment of increasing quantities of radioactive materials.
  5. Adequacy. Whatever combination of energy technologies is used by a modern industrial state, its energy system must provide sufficient energy. The present energy system of the U.S.—primarily gasoline for transport, coal and nuclear (primarily) for electrical generation, and oil for heating some buildings—does supply adequate energy; however, some experts maintain that given increased end-use efficiency, the industrialized countries could shift almost entirely to alternative energy sources in about 50 years. If technically feasible this would increase self-sufficiency and decrease fragility, hazardousness, and pollution, but is not likely to occur without a major shock, or several major shocks, to the conventional energy system, as for example a major terrorist act involving a nuclear power plant, a second oil embargo, or radical climate change. In the meantime, prices are falling slowly for alternative energy sources, especially wind and solar, making them increasingly competitive on the market with conventional electricity sources. Gasoline continues to be the only affordable energy source for most vehicles, with the mileage of the United States fleet recently declining rather than rising.

One change in the present U.S. energy system that, if technically feasible, would increase self-sufficiency by decreasing dependence on oil and which would also decrease pollution is a long-term shift (probably only partial) to hydrogen "burned" in fuel cells. Fuel cells are chemical reactors in which a fuel (not necessarily hydrogen) combines with oxygen to create electricity, with water vapor as the only by-product. Hydrogen is available on Earth only in chemically stable combination with other substances (e.g., in H 2 ; it is therefore not a primary fuel but, like electricity, a form of energy, and must be manufactured either by using electricity to split water molecules or by chemical processing of a fuel such as coal. Although hydrogen is not currently available in large quantities and fuel cells remain expensive (i.e., about 10 times as expensive, per horsepower delivered, as a conventional automobile engine), U.S. President George W. Bush has announced two funding programs for hydrogen fuel cells: Freedom Car (2002) to accelerate development of hydrogen-powered automobiles, and Freedom Fuel (2003), to accelerate development of techniques for manufacturing hydrogen from coal. Freedom Car receives about $50 million per year, and Freedom Fuel has been allotted $144 million per year for five years. The announced goal of the twin programs is to make fuel-cell powered cars commercially available in 20 years. The United States is working in partial cooperation with the European Union, which also seeks to develop hydrogen-powered fuel cells for cars. The European Union's program, unlike the U.S. Freedom Fuel program, seeks to produce hydrogen using electricity generated by wind and solar power.

█ FURTHER READING:

BOOKS:

Brockris, J. O'M. Energy Options. Redfern NSW, Australia: Halsted Press, 1980.

Lovins, Amory, and L. Hunter Lovins. Brittle Power: Energy Strategy for National Security. Andover, MA: Brick House Publishing, 1982.

PERIODICALS:

Banerjee, Neela. "U.S. and Europe in Fuel Cell Pact." New York Times. March 7, 2003.

SEE ALSO

DOE (United States Department of Energy)




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