photos: green wombat
The June issue of Business 2.0 is on the newsstands and features Green Wombat’s story on the coming boom in utility-scale solar power plants. The story is now online. I traveled around the American southwest, Portugal and Australia to report on the solar land rush unleashed by utilties’ demand for renewable energy. As usual, I accumulated way more material than there was space for in a print magazine feature story. So over the next few days, Green Wombat will be running bonus material on the solar startups and technologies I profiled for Business 2.0. Today, the focus is on Stirling Energy Systems, the Phoenix company that has secured contracts with utilties Southern California Edison (SCE) and San Diego Gas & Electric (SRE) to install as many as 70,000 Stirling dishes (photo above) in the Mojave Desert that could power as many as a million homes. The dish tracks the sun, its mirrors concentrating the sunlight on a hydrogen gas-filled Stirling heat engine. As the superheated gas expands it drives pistons, which generate clean, green electricity. The technology dates to the late 1970s, when Ford’s aerospace division
developed the Stirling dish in the wake of the oil shocks of the era.
McDonnell Douglas subsequently took up the effort in the 1980s and then sold the
technology to Southern California Edison, which in turn passed the dish
in 1996 to a startup called Stirling Energy Systems.
In March, I flew to Phoenix to meet with Stirling CEO Bruce Osborn –
who worked on the Stirling dish as a 22-year-old Ford engineer in the
’70s – and executive VP Bob Liden, both veterans of the auto industry. Although the Stirling dish is one of the most efficient ways to convert sunlight into electricity, the sheer sheer scale of the California utility projects – the contracts call for Stirling to provide up to 1.75 gigawatts of solar electricity – has prompted doubts among the company’s rivals about its ability to manufacture so many dishes and engines and keep them operating. “The rocket science part of it has been completed,” Osborn told Green Wombat at Stirling’s headquarters, tucked away in an office park north of downtown Phoenix. “What we�re doing now is taking the units that work well and perform well and making the changes so they�re amenable to high-volume manufacturing.”
Liden argues that scaling up from the six dishes the company currently operates in New Mexico to tens of thousands of dishes isn’t as daunting as it seems. “If you�re talking to a finance guy, he might take a look at it and say this going to be absolutely impossible to make happen,” says Liden. “But if you take someone who comes out of manufacturing, like at Ford or GM, they say, hey, we do this all the time. Yeah, you have to start some place, with some hand-built units. That�s what they do when they build a new car. Once you figure that out, you turn it over to the guys who know how to do the manufacturing engineering, the industrial engineering, and before long, bango, before long you can put these things out pretty darn fast.”
One of Stirling’s partners is investing $20 million to build a factory in Arizona that will manufacture the dishes on an assembly line, according to Osborn. “The ability to scale up is not difficult here at all,” he says. “I think the key factor is to get the cost out of it. There�s capacity now for building these but it’s really a cost issue.”
Stirling also been focusing on developing operation and maintenance programs for the power plants. “How do you do the mirror washing most efficiently, how do you make sure the equipment is all going to be up there for a very high availability rate,” says Liden. “The thing that is attractive to utilities is that if we have a 500-megawatt project it�s 20,000 dishes. If they have a few dishes that go out, that for whatever reason need to have some maintenance and repair, it�s hardly noticeable a tick on the needle.”
A week later I’m driving down a deserted desert road with Osborn, deep inside Kirtland Air Force Base outside Albuquerque. There’s an X-Files vibe to the place. Jets streak over the
vast military reservation and we hear the muffled boom of distant explosions. Narrow
roads snake off into the hills where nuclear scientists work on classified experiments. But there’s no hiding Sandia National Laboratories’ solar thermal testing
grounds from view. A 200-foot solar tower looms over a collection of dishes, troughs and other solar technology from a bygone era. But among the rusting hulks are six shiny Stirling dishes that form a prototype power station. Stirling Energy Systems is working with Sandia’s scientists to perfect the technology and adapt the design for mass production. As luck would have it, it’s a cloudy morning. But when the sun breaks through the giant dishes come to life, pivoting in unison to face the sun. The mirrors on each dish focus the sun’s rays on a Stirling engine suspended on struts over the dish’s focal point. The tip of each engine glows with an intense white light. In a nearby control room, a digital dial on a flat-screen monitor spins as 150 kilowatts of greenhouse gas-free electricity begins to flow into the base’s power grid. Over in another building, engineers are testing a Stirling engine as a film crew trails Osborn, shooting a promotional video for San Diego Gas & Electric. Later this year, Stirling will begin building a 1-megawatt demonstration power plant for Southern California Edison in the Mojave Desert, east of Barstow, California. Hurdles remain, not the least of which is obtaining financing for Stirling’s huge utility projects. But says Osborn, “It�s now about execution. And execution is all about focus and intensity. The other stuff will come.”