State-of-the-Art Solar Collectors For Clean Energy

Luz system in Mojave Desert boasts world's most advanced solar-thermal technology. LIGHT POWER

HUNDREDS of rows of troughlike parabolic mirrors glint sharply beneath the scalding desert sun. Tracking the golden orb across a cobalt sky with the aid of computers, the mirrors focus their rays upon a vacuum-sealed tube of synthetic oil. The oil - once braised to a bubbly 735 degrees F - is pumped into a water-filled steam compressor that turns the water to steam and turns an electric turbine. Down the road a spit, in the sprawling metropolis of Los Angeles, the generated electricity powers microwaves, lights, air conditioners. The nearly 200 megawatts generated can meet the residential needs of about 270,000 people. A planned billion-dollar-plus expansion here by 1994 will triple that output to meet the residential electrical needs of a city the size of Washington.

Here at Kramer Junction, the largest solar-powered facility ever built generates an estimated 90 percent of the world's electricity drawn from the sun. Welcome to the present and future of solar power in both the United States and the world. According to the Solar Energies Industry Association, this 1,000-acre facility is the most advanced worldwide effort to bring solar energy into large-scale production.

The solar-thermal technology represented by these rows of mirrors is one of three forms of solar energy production now used: the solar panel, which is mostly used to heat water above or near a house; photovoltaic cells that use silicon wafers to generate electricity on contact - and are also used in watches and calculators; and the Luz technology here.

``What needs to be learned [about this facility] is that this project is not a fluke but the beginning of a major trend,'' says Scott Sklar, executive director of SEIA, a trade group. ``The US will begin seeing these plants multiplying in New Mexico, Arizona, Nevada, Texas, and California.''

``Luz has been the firm that has taken the state-of-the-art technology, pushed it, applied it, taken corporate risks,'' adds Robert San Martin, deputy assistant secretary for renewable energy at the Department of Energy. ``It is very clear that this is the cutting edge.''

Spurred by anxiety over acid rain and global warming caused in part by burning fossil fuels to produce electric power, at least four major bills are working their way through Congress with measures aimed at harnessing the sun's cleaner energy. Among them, the National Energy Policy Act of 1989 calls for relaxation of current restrictions on the size of solar plants and significant sums for research and development. The bill has 30 cosponsors and broad bipartisan support.

``It's time to look once again at renewable, nonpolluting sources of energy,'' says Sen. Timothy Wirth (D) of Colorado, whose Senate Energy and Natural Resources Committee held congressional hearings in Los Angeles last month on both the greenhouse effect and the problems of smog in the Los Angeles Basin. To attract attention back to solar, Mr. Wirth trotted out some Hollywood celebrities - Dennis Weaver, Morgan Fairchild, and others - to the Luz site for a live press conference for radio and television stations across the West.

``We've got to keep pushing it ... to alert the country that real alternatives do exist,'' he said.

Low oil prices over the last eight years have meant reduced incentive to develop alternative energy. Department of Energy funding for research and development has dropped from 800 million in 1980 to this year's budget request of $81 million, well behind both West Germany and Japan. Research specifically designated for photovoltaics has dropped from $150 million in 1981 to $35 million this year.

The Luz company - whose solar power is three times as cost effective as photovoltaics and uses one-fourth of the land - was founded in 1979 in Los Angeles by Arnold Goldman, an American engineer and Patrick Fran,cois, a French financier.

``We felt we're buying into the dawn of the solar age,'' says Newton Becker, chairman of the board and one of the company's largest investors. ``Now, despite a huge collapse in the price of oil [currently between $18 and $20 a barrel] we still firmly believe it.'' Late last year, technological advances in photovoltaic research accompanied announcements by the Chronar Corporation of Princeton, N.J., to build a 50-megawatt photovoltaic plant near here, but no contract has been signed. The largest photovoltaic plant generates about 6.5 megawatts.

Whereas initial units generated power at about 24 cents per kilowatt-hour, technological improvements - patented sun sensors, vacuum-insulated pipes - have lowered costs to about 8 cents. As economies of scale, costs could be lowered another 2 cents if plant-size restrictions were lifted - currently mandated by the Public Utilities Regulatory Practices Act in 1978. Restrictions were written to appease utility companies concerned about competition from alternative sources.

``In a few years, this solar-thermal technology will be absolutely price competitive with any form of energy under any scenario,'' says Luz's Paul Savodelli. The Luz-type facilities depend on sustained, high-intensity sunlight and are thus suited to location primarily in the US Southwest and similar areas worldwide.

One major attraction of Luz-type facilities, say Mr. Sklar, Mr. San Martin, and others, is that they are modular in nature and have a start-up time of only 18 months. ``You can't even get approval for a conventional power plant in that amount of time,'' says Robert Meyer of the Department of Energy. The modular nature makes them attractive to municipalities with limited funds who want to expand facilities each year.

The Luz International Ltd. System began here in 1983 with a 14-megawatt solar plant in nearby Dagget. They have since graduated to seven so-called ``solar farms'' that employ 650,000 slightly concave mirrors, heat exchangers, and traditional-style turbine generators. Though the 196 megawatts that are generated represent only 1 percent of Southern California Edison's peak demand, all the energy is purchased from Luz by Edison as required by the the 1978 regulatory act.

Impressed with performance, Edison has given Luz five additional 30-year power contracts, according to Pam Easterwood at Edison. The energy has been used mostly during peak and overflow periods. When such power is needed at night, the Luz facility is allowed by law to produce up to 25 percent of its power by natural gas as backup and to sustain performance. That has helped assuage one chronic complaint against solar power - reliability.

Beside the obvious nonpolluting, renewable aspects of solar power, company officials say, the start-up and maintenance costs of Luz systems are far less.

Wirth, Sklar, and others are concerned about the loss of investment tax credits and energy tax credits begun in the mid-'70s that helped buttress Luz's early years. They are due to expire this December. According to Luz CEO James Bazor the company will be out $25 million if those investment credits end. Beside tripling capacity here in the next five years, the company is planning similar plants in Nevada, Mexico, Arizona, India, Spain, and Brazil.

``Projects such as Luz are extremely sensitive to increases in interest rates and the price of oil,'' adds Mr. Savodelli. ``The tax credit gives us that buffer that helps us stay competitive with other forms of energy while we continue to develop the technology.''

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