Looking Into the Sun
A relentlessly blue sky stretches over the sparse, nappy scrub and cacti in the desert several miles outside Albuquerque. Here, where there is otherwise little in any direction to suggest human existence, a lone, dusty road has led to a few unremarkable bungalows. Alongside them is a less unremarkable sight: a cluster of a half-dozen satellite-style dishes that look big enough to pick up programs from the outer planets. But these house-size dishes don't traffic in television. Their mirrored surfaces are aimed directly at the sun, twisting a few inches every six seconds to track it across the sky. Each dish focuses the equivalent of 10,000 suns' worth of heat on an eight-inch-wide maze of thin metal tubing perched above the dish's center.
Admiring one of the contraptions from below is David Slawson, a somewhat diminutive fellow in a leather jacket and slacks. Slawson may not cut an impressive figure, but he makes up for it with ambition. His dishes are self-contained, electricity-generating plants, fueled by the particles of energy hurled across 93 million miles of space by the nuclear reactor sitting at the center of our solar system -- that is, the sun. Slawson's quixotic plan: to cover large swaths of the earth's desert regions with emissionless solar farms. "A farm 100 miles by 100 miles would be enough to displace the fossil-fuel consumption of the U.S.," he says, sweeping his hand as if this vast installation already lies just off to the side. The dishes, he adds, will also help bring cheap electricity to the planet's 1.5 billion rural poor currently living without it.
"A solar farm 100 miles by 100 miles would be enough to displace the fossil-fuel consumption of the U.S."
Heady stuff, to be sure, and easy to dismiss. On the other hand, Slawson's company, Stirling Energy Systems, has some interesting credentials, including ownership of technology developed by McDonnell Douglas, Southern California Edison, and others at a cost of $400 million; $3 million in grants from the Department of Energy; a steady flow of angel investment that he says has averaged $2 million a year for nine years; a preliminary agreement to provide a major utility with up to $2.7 billion worth of electricity over 20 years; and another $1.3 billion deal on tap with another utility.
Slawson, 57, came to the unlikely role of would-be slayer of the world's monster oil habit through an even more unlikely route. He was running an alternative health care school in Portland, Oreg., in 1989 and had just moved to an apartment downtown. On his first night there, he opened his window before going to bed -- and got a faceful of vehicle exhaust. What, he wheezed to himself, is this world coming to? And more important, what was he, David Slawson, going to do about it? Charging across the street to a library first thing in the morning, he found his answer.
Solar energy seems like a no-brainer -- hey, free energy from the sky, what's not to like? -- but on closer inspection some thorny issues pop up. The biggest one is the "conversion efficiency" issue. Sunlight is energy, all right, but it needs to be converted to a form that can be used to run cars, heat homes, and display Leno. Electricity fills the bill, but a funny thing happens when you enlist sunlight to create electricity: Most of the energy flits away uselessly. The most common approach is to use sunlight to knock electrons out of a semiconducting material like silicon, creating an electric current. But the efficiency of even the very best photovoltaic systems, as the approach is called, tops out around 15% -- in other words, 85% of the sunlight's energy is wasted. Big, expensive solar panels in very sunny areas produce relatively little power, which winds up costing about 25 cents per kilowatt hour of electricity. (A kilowatt is about enough to power 14 75-watt bulbs.) Electricity from a conventional natural-gas-burning power station, by contrast, costs about seven cents per kilowatt hour.
Slawson's library raid turned up a book that detailed a different approach: a thermoelectric solar dish system developed by McDonnell Douglas (later absorbed into Boeing) with a Swedish firm called Kockums, technology that was later sold to and tested by Southern California Edison. Instead of using rays of sunlight to knock out electrons, the dish reflects and concentrates the rays in order to heat and thus expand a gas. That expansion is then put to work by a device called a Stirling engine to turn a conventional electric generator. The approach is nearly twice as efficient as most photovoltaic systems -- while doing away with semiconductors and other expensive materials.
These solar dishes are the world's great hope for renewable energy, says Slawson. Sure, there's hydropower, but there are only so many Niagara Falls. Drilling and other operating costs limit geothermal power, which taps heat energy trapped below ground. There's wind, but finding frequently windy sites where windmills don't spoil scenic vistas is a challenge -- and even then, the wind tends to die down during the summer and in the daytime, when demand is highest. And forget fuel cells -- they generate electricity, but the hydrogen they run on comes either from fossil fuels or by zapping water with electricity that still needs to come from somewhere else. "If you're an electric utility that wants renewable energy and you can get hold of a big plot of desert land, you're going to look at solar thermoelectric," says Michael Eckhart, a former General Electric and power industry executive who now heads the American Council On Renewable Energy in Washington, D.C.
Stirling Energy's technology isn't the only thermoelectric approach, but so far the others can't match its efficiency. In any case, the real competition to any renewable energy source is not other new technologies but conventional power generation. And the energy industry is notoriously resistant to change. "This is not a go-fast industry, like telecommunications or computers," says Eckhart. Unless regulation or customer preferences force utilities to go whole hog into renewable energy, Slawson will have to get his dishes to produce energy reliably at pennies per kilowatt. That means finding ways to manufacture the systems more cheaply and get more electricity out of each dish.
The company is working furiously on both goals in facilities set up in the desert bungalows outside Albuquerque. Slawson employs some 30 people, many from the teams that first developed the technology, and they are engaged in an endless game of tweaking. The original prototype dish and engine would have cost $300,000 each to manufacture in quantity. That would have led to a $6 billion price tag for setting up the 20,000 dishes required to put out the 500 megawatts of a typical generating station, about enough to light a medium-size city.
To slash costs, the engineers replaced Boeing's airplane-style, customized, sheet-metal-and-rivets approach to the dish frame with a mass-producible, bolted, rolled-steel design. A custom heat exchanger was replaced with off-the-shelf racecar radiators, and the 82 three- by four-foot mirrors that cover each dish's surface, which originally cost hundreds of dollars apiece, are now producible for less than $30 each by the same process used to create makeup compacts. Slawson says he can build a dish system for about $25,000 -- bringing the total price of a 500-megawatt installation to about $600 million, about the same as a conventional generating station. The bottom line: Slawson claims he's already capable of turning out electricity at less than eight cents per kilowatt, making it competitive with a gas-fired plant. "I don't want to say how much less than eight cents it costs me because I don't want to have to sell it too cheaply," he says. "Just cheaply enough to win contracts."
Slawson says he's close to signing a contract for a 500-megawatt solar farm with a major California utility (which he declined to identify); another utility has placed Stirling on a short list for a second 500-megawatt farm. In early 2007, he plans to manufacture 300 dishes a month; he'll bump that up to 1,000 a month by 2009. Unlike a conventional power station, which doesn't produce any juice until it's completed, a solar farm can in theory begin financing itself long before the last dish is up. "We can generate revenue as soon as we start putting dishes in," says Slawson. By 2010, he predicts, Stirling Energy will be pulling in $300 million a year.
That's a pretty bold business plan for a fellow who started out flipping burgers at a Portland Bun 'N Burger he bought with a friend in 1971, shortly after college. Slawson sold the restaurant after a few years and became a massage therapist; by 1978 his practice had become an extensive alternative health care facility that eventually employed 70 professionals. In 1981 he acquired a small alternative health care school and built it into one of the largest such schools in the country -- the East-West College of the Healing Arts. Then came the move to downtown Portland in 1989 and the awakening of his solar consciousness.
Following a stint living in Maui, Slawson returned to Portland. In 1996, he learned that Southern California Edison had been cutting back on R&D and was looking for a buyer for the solar dish technology. The price tag, Slawson says, was "hundreds of thousands of dollars." Slawson raised the money from family, friends, and various well-heeled green contacts he had made over the years -- there's overlap between the massage-homeopathy crowd and clean-air enthusiasts -- and founded Stirling Energy Systems in Phoenix, the unofficial capital of the desert Southwest. By February of 1996, Slawson was in the solar energy business.
His scrappy, New Age background may turn out to be an important strength. The Renewable Energy Council's Eckhart says that when it comes to new sources of power, utilities aren't concerned just with kilowatt pricing -- they also want to be sure the company that's providing it will survive to make sure the juice keeps flowing. In the end, he says, it may be Slawson's unwavering, decadelong commitment that clinches the sale. If Stirling Energy can parlay that passion into a big utility sale, Eckhart adds, other utilities are likely to follow "as a herd." If that happens, says Slawson, he expects buyout offers to come flying in from utilities, oil companies, and other big players. But he's not interested in selling. His goal is to go public and partner with established giants on some really, really big solar farms planted on sun-scorched land that now mostly goes to waste. "If we can cover 1% of the world's deserts," he says, "we can produce 100% of the world's energy needs."
Contributing editor David H. Freedman writes the "What's Next" column.