As Power Crisis Worsens, Solar Taking its Place in the Sun

HUNTINGTON BEACH, Calif. - Like giant robotic sunflowers, the machines that Boeing engineer Kenneth Stone has tended for nearly 20 years awaken with the dawn.

Planted in a sunny spot between a hangar and an office trailer on a Boeing compound in this Southern California beach town, these shimmering 50-foot-tall solar dishes tilt their mirrored petals to the morning glow. Through the day, they slowly pivot, tracking the sun's arc across the sky, capturing, reflecting and focusing its rays to power an attached engine that generates electricity.

In his mind's eye, Stone sees vast, beautiful fields of solar dishes sprouting in the deserts of the Southwest, converting sunlight into electricity to power cities - without producing pollution, without accelerating global warming.

Has Stone been out in the sun too long? Not according to energy experts.

"This isn't some mad scientist's mad dream. This is real," says Terry Peterson, a solar market specialist with the Electric Power Research Institute, a nonprofit research institute funded by the power industry.

Solar is on the brink of a breakthrough, its prospects brightening as the nation's power crisis spurs investment in alternative energy by municipalities, businesses and home owners. The mayor of sunny San Diego, hit hard by soaring electricity prices last summer, envisions the city's landfills covered with "solar farms" that both harness the sun's rays and burn landfill gasses.

Up the coast, San Francisco's supervisors are proposing a $100 million solar bond to install photovoltaic panels on municipal properties. Meanwhile, Fortune 500 powerhouses such as Bechtel, Boeing and Scientific Applications International Corp. are pursuing a more ambitious dream: bringing to market large-scale, centralized solar power.

Demonstration projects are already running or being developed in Arizona, Nevada and Spain.

Stirling Energy Systems, a company that owns the dish technology that Boeing is helping to develop through a U.S. Department of Energy contract, has struck deals with utilities in South Africa and Spain for test projects. "We're optimistic," Boeing project manager Mike McDowell says of the technology that Stone has nurtured. "We're trying to create a market."

Stone's specialty is Stirling dish technology, one promising branch of the family of renewable "solar thermal" energy sources. Although most people equate solar energy with rooftop panels that produce modest levels of wattage to help heat homes and run appliances, solar thermal technologies are designed to provide power on an industrial scale.

An early-generation "solar trough" thermal plant built in the 1980s in the desert near Barstow, Calif., generates five times the wattage produced by all the solar panels in the United States. The system, which generates 354 megawatts - enough to power about 350,000 homes - focuses the sun's rays to heat tubes filled with a synthetic oil; the heated oil runs steam turbines to produce electricity. Stirling dish technology is even more efficient at converting the sun's energy into electricity, according to a Department of Energy study.

Another solar thermal technology, known as "power tower," is superior to the trough as well. While less efficient than the Stirling dish in converting the sun's energy to electricity, it possesses a storage system that stretches power production beyond sunset. Bechtel subsidiary Nexant is developing a massive power tower project in the Spanish region of Andalucia. More than 1 square kilometer of mirrors will focus the sun's rays to heat a tower filled with tubes of molten salt. The heated salt stores energy that powers electricity-producing generators.

So why has the United States let these promising solar technologies languish for two decades? The question is even more urgent considering the international campaign to curb global warming caused by the burning of fossil fuels. The answer lies in the geopolitics of energy, the inconsistency of domestic power policies and the economics of a volatile marketplace in the throes of deregulation. Shifts in all these areas will determine the fate of solar development.

Scientists have recognized the potential of Stirling technology for generations. The Stirling engine is an external combustion engine, relying on heat to cause hydrogen to expand and drive the pistons. Robert Stirling, a Scottish minister, conceived of the closed-loop engine in the early 1800s as an alternative to steam engines, which had a lethal habit of blowing up. A French inventor later attached a solar collector to a Stirling engine, according to Barry Butler, a Scientific Applications International VP overseeing its energy division.

Stirling engines, he says, are now used in everything from submarines to prototypes of artificial hearts used in animals. SAIC has developed a hybrid Stirling dish that runs on sunlight during the day and burns landfill gases at night to provide power. The company is in discussions with San Diego about constructing solar power plants on its landfills.

The Stirling engine remains buggy, and maintenance is a concern, experts say, but technological advances make engineers optimistic about its prospects. The Stirling engine is "about where the car engine was in the 1950s," Stone says. "From a technology standpoint, I don't see anything that would stop this. But so many political things have stopped it before."