By Glenn Garelik
Drilling in the Arctic National Wildlife Refuge would yield 4.25 to 11.8 billion barrels of oil, according to the U.S. Geological Survey--a 6-month to 20-month national supply, even at a rate of consumption that doesn't grow. What's more, the ANWR cache wouldn't be accessible much before 2010, and wouldn't peak for years after that. But a more imaginative mix of fuels--and using what we've got more efficiently--would yield much more power. "There is no silver bullet," says Virinder Singh, research director at the nonprofit Renewable Energy Policy Project, "only silver buckshot." Herewith, a review of some alternatives.
Efficiency
America has already seen how well efficiency measures can work. The Electric Power Research Institute, the utilities' trade association, notes that since the Arab oil embargo of 1973 the United States has gained three times as much energy from efficiency--savings that have come to be taken for granted--as from all net expansion of domestic supplies combined. Many additional efficiency measures remain that could be undertaken now, some virtually cost-free and overnight.
Over the long term, according to government laboratories, smarter use of conventional energy sources could halve demand for new power plants. The American Council for an Energy-Efficient Economy, a think tank based in Washington, D.C., says that increasing the fuel efficiency of cars, SUVs, and minivans to 35 miles per gallon could save as much as 1.7 billion barrels of oil a year by 2020.
Electric Power
Wind
pros: Pollution-free. Land around turbines is usable (e.g., agriculturally) virtually right up to the machinery. Towers can be up and running six months after permitting. When well sited, costs less than 5¢ per kilowatt-hour (kWh), according to American Wind Energy Association (AWEA).
cons: Requires minimum average wind speeds. Because winds are unpredictable, output cannot be timed to match demand. Turbine blades can kill birds.
status: Turbines produce two and a half times more energy per unit than five years ago, at one-fifth the cost. Wind power has grown 58 percent in past decade, the fastest of all renewables. Research is under way on storing "excess" energy generated during strong winds. Careful study before siting can keep towers away from (and lower than) migratory flyways.
forecast: Cost could drop another 35 to 40 percent by 2006, according to AWEA, and wind could provide as much as 6 percent of U.S. electricity by 2020.
Solar
pros: Direct solar (for heating) and photovoltaic cells (for electric power) are fuel-free and essentially pollution-free. In most places, peak generation (midday) coincides with peak demand.
cons: Sunlight-dependent. Limited storage options; batteries are inadequate, inefficient, short-lived. Relatively expensive.
status: Private homes account for 90 percent of the 1 to 2 million solar systems now operating, though most common use is to heat swimming pools. "Thin-film" cadmium telluride cells should be cheaper to make than earlier, brittle, silicon films.
forecast: Mass production could lower manufacturing costs, encouraging interest. Most practical as supplementary source; when sun is not shining, "utility inter-tie" can automatically switch to power grid.
Hydropower
pros: Most efficient current form of power generation (as much as 90 percent of potential energy becomes electrical energy). Highest output. Most able to adjust output quickly.
cons: Damming rivers can endanger aquatic flora and fauna. For instance, as many as 88 percent of juvenile salmon are killed by hydroelectric dams on Snake and Columbia rivers. Expensive, slow to build.
status: More than 2,000 dams in United States, accounting for 11percent of all electricity generation and 81 percent of generation by renewables.
forecast: White House energy plan calls for streamlining licensing and relicensing procedures.
Biomass
pros: Emits very little net carbon dioxide (the chief "greenhouse" gas). Turbines are driven by controlled combustion or enzymatic "digestion" of biomass--agricultural and animal waste, tree prunings, yard clippings, urban wood, sawdust, and, potentially, fast-growing trees and grasses raised for the purpose. Environmentally superior to alternative disposal methods (landfill and open burning).
cons: High capital investment; payback period is at least 6 years. Often burned with coal, which creates its own problems (see below).
status: Currently No. 2 among U.S. renewables, but only 20 to 25 percent efficient. New technology should improve efficiency.
forecast: Financial drawbacks could limit growth unless government-encouraged, but White House says it will increase research and development spending on biomass and propose tax credit for fiscal year 2003. Could account for as much as 20 percent of the nation's power, according to American Bioenergy Association.
Geothermal (ground-source heat pump)
pros: Pollution-free, reliable 24/7, wholly renewable. Fluid at ambient underground temperature circulates through pipes to warm or cool buildings, pools, greenhouses. No aboveground infrastructure necessary. Reduces electricity use by 30 to 60 percent.
cons: Costs two to three times as much as a conventional heating system. Must have enough underground space for the ground pipe.
status: Used by more than 400,000 homes in Unted States. Most major furnace manufacturers offer heat pumps.
forecast: Number of facilities using ground-source heat pumps growing at 10,000 to 40,000 per year.
Geothermal (steam turbine)
pros: Virtually pollution-free, largely renewable. Drilling for superheated underground water vents steam, which generates electricity. Necessary aboveground land area smaller per megawatt than for other types of power.
cons: Limited to areas with tectonic activity (in United States, mostly West Coast). Underground water sources can become depleted. Infrastructure must be earthquake-resistant.
status: Currently third among U.S. renewable energy sources (about 5 percent of total renewable energy production). California has enough developable power to double its current geothermal output. Introducing reclaimed wastewater (e.g., irrigation runoff) to hot underground rock can make up for some water loss, also reduce pollution of surface waters into which effluents would otherwise be discharged.
forecast: No current net growth, thanks partly to depletion of fields at extant stations. Better exploratory technologies will identify more likely faults, but growth may remain restricted by more "dry holes" and limited access.
Natural gas
pros: Cleanest of fossil fuels. Fully natural-gas-fueled vehicles could reduce carbon monoxide exhaust by 70 percent, carbon dioxide by as much as 30 percent, and nitrogen oxides by 87 percent, according to the Natural Gas Vehicle Coalition. Virtually no particulates. Surface land used during drilling has shrunk as much as 75 percent since 1970s. Abundant, storable.
cons: Exploration, production are expensive (average offshore well, $4.3 million). Expensive to liquefy. Some of untapped gas is on restricted lands.
status: For space and water heating, supplies more than half of U.S. homes; for electricity, about 15 percent (i.e., third place, after coal and nuclear). As vehicular fuel, powers 100,000 vehicles on U.S. roads. Novel sources (e.g., shale) and price decontrol have increased supply and reliability, but distribution bottlenecks loom.
forecast: Improved seismic techniques (to identify and map stores) and drilling technologies make extraction easier, especially offshore.
Nuclear
pros: Virtually no atmospheric pollutants. Amount of uranium needed to produce energy is hundreds of thousands of times less than with coal. Inexpensive where construction costs have been paid off; last winter, 1.92¢ per kWh on average.
cons: Costly safety and backup systems and protracted licensing procedures have made for enormous initial capital outlay; when included in cost per kWh, nuclear-fired electricity is about twice as expensive as coal or gas. All current U.S. reactors pose risk of leakage and meltdown. Normal reactor operation thermally pollutes rivers and coastal waters; ore processing leaves radioactive tailings. Problematic storage, transport of high-level radioactive waste (currently 40,000 tons and growing at 2,000-3,000 tons a year). Potentially bomb-usable plutonium a byproduct of fission; risk of proliferation for weapons use.
status: About 20 percent of electricity in the United States is generated by 104 nuclear-powered plants (down from 112 in 1990). "Evolutionary" improvements in safety and efficiency have been certified by the Nuclear Regulatory Commission for three large and midsize advanced light-water reactor designs. One company seeks licensing of reactors using new "pebble bed" technology, in which insulated grains of uranium too small to reach meltdown replace fuel rods; instead of steam, inert, recyclable helium passes to turbine to generate electricity. New modular construction would make for small units (inherently safer) and standardized design (less expensive to build), and would incrementally match plant capacity with demand for power. Projected efficiency: 40 percent, up from current 32 percent.
Because of public unease, exorbitant startup costs, and persistent storage problems, no new plants have been ordered in the United States in more than 20 years. By end of 1999 nearly half of all orders ever placed had been cancelled.
forecast: Bush energy plan aims to reduce costs and encourage growth by streamlining plant licensing and relicensing and by maintaining federal limits on industry liability. Several reactors that were left unfinished when demand slowed will likely be completed.
Coal
pros: Abundant domestic supplies. The most competitively priced of U.S. energy sources. Ash, sulfur, nitrogen, and metals emissions have been reduced under the Clean Air Act, but far from eliminated.
cons: Burning coal creates 1.9 billion tons per year of carbon dioxide. Mining and combustion pollute waters; surface mining (especially mountaintop removal) and underground mining can deface land, pollute soil, and obstruct, obliterate, or poison streams.
status: No. 1 U.S. source of power, accounting for more than half of all electricity produced (one-third of total energy). In past half-century prices have dropped 44 percent in real dollars. Efficiencies as high as 40 percent, although typically 33 to 34 percent, according to the National Coal Council, which helps advise the U.S. secretary of energy. "Clean coal" technologies developed during past 15 years have helped reduce pollutants.
forecast: Production and consumption growing. Industry claims efficiencies could reach 50 to 55 percent within 10 years. Many coal-fired power plants are nearing retirement, so proportion built with clean-coal technologies and higher efficiencies should grow; about 20 have been announced in past six months.
Transportation
Fuel cells
pros: Create electricity by combining hydrogen and oxygen; sole byproduct is water vapor. Quiet. Potentially much more efficient than internal combustion engine.
cons: Costs remain much higher than conventional power sources. Near-term, hydrogen for fuel cells will likely come from natural gas or gasoline, producing emissions.
status: All the major automakers are investing in fuel cells, and most have models coming out by 2003.
forecast: Latest research concentrates on fully fuel-cell-operated vehicles. Mass production could lower manufacturing costs.
Ethanol
pros: A product of corn processing, this auto fuel (for "flexible" fuel systems) or fuel "extender" (for gasoline blends) burns more completely than gasoline, reducing emissions. High octane level reduces need for antiknock additives. Ten-percent blend gets same mileage per gallon as gasoline, often with cheaper per-gallon costs. Product of a domestic crop, so not subject to vagaries of foreign relations.
cons: Until a decade ago, energy needed to produce ethanol offset gain. Automakers manufacturing ethanol-gasoline vehicles currently receive credits allowing them to lower average mileage of rest of fleet, paradoxically making for increased total gasoline consumption. Most corn growers use large amounts of chemical fertilizers, pesticides, herbicides.
status: "Conversion efficiency" has increased in past five years; 600 million bushels of corn yielded 1.63 billion gallons of ethanol in 2000. More efficient manufacturing plants have dramatically lowered energy used to produce ethanol, making for net gain. Blend of 10 percent ethanol, 90 percent gasoline can drive all cars; for specially designed vehicles, ethanol content can run to 85 percent. U.S. automakers have manufactured 1.2 million ethanol-gasoline vehicles; however, the high-ethanol fuel mix is available at just 101 of 176,000 service stations nationwide.
forecast: Business has doubled in past 10 years, according to industry association. With more government support, could see even faster growth.
Biodiesel
pros: Made from fresh or used vegetable oils or animal fats. More completely combusted than regular diesel, producing substantially less carbon dioxide, hydrocarbons, particulates, carbon monoxide; virtually no sulfur dioxide; inoffensive odor. Can be used directly in existing diesel engines, or blended with petroleum diesel fuel in any ratio (usually 20:80). Higher lubricity than petroleum diesel can help extend engine life. Available from domestic crops.
cons: Can slightly raise nitrogen oxide emissions.
status: Has grown rapidly since 1992 introduction, to 20 million gallons projected for 2001 (total regular diesel used in FY '99: 57 billion gallons). Used mostly by government fleets. Manufactured large-scale by just a few U.S. companies.
forecast: Growth could expand through smaller-scale manufacture. National Biodiesel Board projects that use will quadruple every year for next few years.
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