Science & Technology
THE SUN SHINES BRIGHTER ON ALTERNATIVE ENERGY
In the late 1970s, alternative energy was nearly as popular in California as alternative lifestyles. Fertilized by state and federal tax incentives, windmills sprouted east of San Francisco by the thousand. Patches of the Mojave Desert were carpeted with panels that collected the sun's energy. But when the tax breaks dried up, so did the projects. Luz International Ltd., a top maker of solar gear, went bankrupt.
The times are changing, however. Bolstered by improved technology and revived support from Washington, renewable energy is making a comeback--and not just out West. On Aug. 6, some 68 utilities across the country agreed to buy as much as $500 million worth of solar panels over the next five years to generate electricity. Two weeks later, utilities in Maine, Texas, and Vermont signed on for Energy Dept. tests of new, more efficient wind turbines. And in October, the industry-funded Utility Renewable Resources Assn. decided to refocus exclusively on finding clean ways to burn biomass--wood and other plant material. "We're seeing a revolution in the way we create and use power," says Frank M. Stewart Jr., acting assistant energy secretary for efficiency and renewable energy. Already, Southern California Edison Co., a pioneer in such efforts, gets 13% of its electricity from these renewable sources vs. 1% in 1985.
"TRUCKING ALONG." Most of the renewables are still infant technologies with big cost disadvantages (table). So they won't displace fossil fuels right away, if ever. Currently, nearly 55% of the nation's electricity comes from coal, 22% from nuclear reactors, 13% from oil and natural gas, and about 9% from hydro generators. Wind and solar power account for less than 1% of the total, a share that's expected to rise only slowly.
Still, after being slashed by 76% during the Reagan era, federal spending for research on renewable energy will climb 36% in fiscal 1994, to $347 million. If this money is used well, says Robert L. San Martin, deputy assistant secretary for utility technologies at the Energy Dept., perhaps 5% of U.S. electricity could come from wind and sun within 20 years. Well before then, the market opportunities could be tantalizing. "If we supplied just 1% of the world's electricity by the end of the century, we'd be trucking along at $3 billion to $4 billion [in sales] a year," says Gerald R. Alderson, president and CEO of Kenetech Inc. in San Francisco, the nation's largest wind-power company.
Wind power, in fact, "is on the doorstep of commercial reality," says Edgar DeMeo, manager of the solar-power program at the utility-funded Electric Power Research Institute in Palo Alto, Calif. Since 1981, commercial power generated from wind worldwide has leaped from 15 megawatts to 2,652 megawatts, according to the Worldwatch Institute, a nonprofit research body in Washington. The U.S. generates most of this--65%. But maybe not for long: Worldwatch experts say that by 2005 the European Community aims to be generating 8,000 Mw of electricity from wind, or 1% of its total.
FASTER SPIN. Those windmills will be more sophisticated than the giant propellers that covered California's Altamont Pass in the 1980s to catch the powerful Pacific breezes. None of those early models could generate electricity for less than 7 1/2 per kilowatt hour, 50% more than from coal or nuclear. But in late 1991, a Kenetech subsidiary, U.S. Windpower Inc., unveiled a better turbine, the 33M-VS. The company is now selling electricity from this machine for as little as 5 per kwh.
To finance production of the new turbine, Kenetech went public in September, raising $92 million. Alderson says the company has $600 million in firm orders from such utilities as New England Electric System, which will buy roughly 20 Mw of wind power by 1998. Last April, meanwhile, U.S. Windpower formed a partnership with a Ukrainian utility called Krimenergo to build a 500-Mw wind farm on the Crimean peninsula in hopes of hastening the closure of nuclear plants at Chernobyl. The company is also negotiating with the European Utility Consortium to provide 150 Mw of power--enough to run about 50,000 homes--by 1999.
Sitting atop a 90-foot tower, its 54-foot-long blades facing into the breeze, the 33M-VS looks like any other wind machine. But it isn't. Until it came along, turbines spun at a constant velocity, no matter how hard the wind blew. This was necessary to generate alternating current with a frequency of 60 hertz, as used in the U.S. By contrast, the Kenetech machine accelerates or slows down as wind speed changes, and a computerized converter produces a steady 60-hertz current. It thus captures more energy as the wind blows harder, and it can take strong gusts without breaking --as earlier models did.
FloWind Corp. in San Rafael, Calif., is doing well, too, with a new turbine that produces electricity for 5.3 per kwh. Its blades spin at a constant speed, but a new blade design allows the turbine to draw extra power from strong winds. FloWind has won its first order for the new turbines, from Washington state's Bonneville Power Administration, which will build a 91-unit wind farm by 1995.
Solar power is about a decade behind wind, experts say, in the race to become commercially feasible. Still, scientists are steadily improving the efficiency of solar cells, a key to getting prices down. In July, scientists at the National Renewable Energy Laboratory set efficiency records for two technologies. Thin-film cells made of copper indium diselenide and gallium converted 15.5% of sunlight into electricity, surpassing the 15% mark for the first time. Tandem cells made of gallium indium phosphide and gallium arsenide, which soak up different parts of the light spectrum, reached 29.5% efficiency, up from 27.6%. Energy Dept. scientists say Martin Marietta, Solarex, Siemens Solar Industries, and International Solar Electric Technologies are monitoring the developments in thin-film technology with an eye to making solar cells for utilities.
SALTING IT AWAY. SoCal Edison is also working on solar advances. In partnership with Texas Instruments Inc., the utility is developing sheets of tiny photovoltaic cells made of silicon. These would be built into roof shingles or other construction materials to generate electricity for homes. The cells now operate at 8.5% efficiency and produce electricity at 16 to 18 per kwh. Joseph N. Reeves, research manager at SoCal Edison, says the companies hope to hit 9% efficiency before deciding early next year whether to commercialize the cells. Despite the high cost, Reeves says, this technology makes sense in some situations. For instance, extending an electrical distribution line can cost $20,000 to $50,000 a mile. "If you pay $10,000 or $20,000 per kilowatt for a photovoltaic system, that still might be cheaper [in remote areas]," says Reeves.
SoCal Edison is also leading a 12-member consortium in a $48.5 million project called Solar Two, which the participants hope will generate as much as 35% more electricity than an earlier project did. Solar Two will use mirrors to concentrate the sun's rays, then store the resulting heat in molten salt to be drawn out later to generate electricity at night or on cloudy days. Salt, it turns out, holds heat much longer than did oil, the storage medium in Solar One. The new project would let utilities use solar energy as more than an intermittent power source, says Reeves, and SoCal hopes to be using it by 2000.
The push for alternative energy sources could also lead to more burning of crops or trees grown especially for that purpose. Some 0.5% of U.S. electricity is now produced this way, a share that is likely to double by 2010. Georgia Power Co. in Atlanta, for instance, burns as much as 2,000 tons of peanut shells and scrap wood a month in place of coal. Using wood is 30% cheaper and reduces harmful emissions, says Dwight H. Evans, executive vice-president.
True, alternative energy is still only peanuts in the nation's energy mix. But with more money from Washington and more support from adventurous utilities, the idea may go further this time.Mary Beth Regan in Washington