Leila Madrone: Solar Energy Roboticist
Otherlab’s Leila Madrone is trying to make solar power finally work
Leila Madrone's earliest aspiration was to work for the National Aeronautics and Space Administration. “When I was seven, I wore a black NASA jacket every single day," says Madrone. A quarter century later, after earning two degrees and designing robots of all shapes and sizes at MIT, she attained that goal, landing a job at NASA's Ames Research Center in Mountain View, Calif.
Her work there—on the GigaPan imaging project, a spin-off of the Mars rover missions—was enjoyable, but deep down she didn't find it satisfying. Madrone wanted her toils to have greater social impact. So after careful thought, she decided to apply her background in robotics to solving some of the problems of renewable energy. Her new ambition is “to make solar energy actually work." She's now pursuing that objective at Otherlab in San Francisco, where she's doing R&D that could one day make solar energy competitive with coal, even in the developing world.
Madrone didn't expect to make significant inroads right away. Her first step was identifying a solar company that could use her skills in robotics so that she could learn more about the solar industry. At the time, GreenVolts, then based in Fremont, Calif., seemed to fill the bill. It was developing systems to concentrate sunlight on high-efficiency photovoltaic cells, so it needed equipment capable of tracking the sun precisely. “This is great," Madrone remembers thinking. “This is robots, but with a solar device on the end of it."
She was discouraged, too, by the economy, which at the time—2009—was taking a beating, causing GreenVolts to lay off most of her engineering colleagues. She decided to leave as well and travel overseas. As she had just gotten married, it would be an extended honeymoon but with a professional component. “I wanted to see how people actually interact with energy in the world," says Madrone.
Her conclusion about solar energy after five months touring Europe, Asia, the Middle East, and Mexico? “It really had to be cheap," she says. “It couldn't just be cheap for someone in San Francisco or the U.S. It had to be cheap for people everywhere."
Returning to California, she wrote in some desperation to Saul Griffith, a friend from her MIT days. Griffith had recently founded Otherlab, which Madrone describes as being “like a cross between a start-up company and an academic lab." By happy coincidence, he, too, had been toying with various solar-energy ideas, and he invited her to improve on his preliminary work.
Their premise was that equipment to harness the sun's rays could be made very cheaply. If the manufacturing costs could be kept low, they reasoned, the price would be proportional to the mass and cost per kilogram of the constituent materials. So the key would be to use, as much as possible, stuff that is both lightweight and inexpensive. What stuff? The answer struck them as obvious. Solar energy's future, to borrow a line from The Graduate, could be summed up in one word: plastics.
Madrone and Griffith eventually got funding from the Advanced Research Projects Agency–Energy (ARPA-E) to work on better ways to steer the mirrors of a solar-thermal-energy plant. These mirrors focus sunlight throughout the day on towers containing steam-driven generators. Mechanisms that accomplish that task—called heliostats—have been around for decades, but they are not cheap.
Madrone and Griffith realized that they could cut down on the heft required of the heliostats by using a huge number of small mirrors to replace what would normally be a smaller number of big ones. Small mirrors hug the ground and thus carry smaller wind loads. And small, light-duty heliostats could be built from plastic, following an approach that's similar to the way certain flowering plants track the sun's daily movements. “Originally, we were origami inspired, and now we're bio inspired," says Madrone.
Her latest prototype aims a mirror by varying the pressures within pneumatically inflated plastic chambers, which can be mass-produced with the same tooling used to make plastic bottles. “If we keep using heliostats that have been around for half a century, there's no way the price is going to go down," says Madrone. “If we don't start taking advantage of new technologies, we're just going to lose the solar game."
A typical workday for Madrone as she tries to win that game might entail consulting with outside experts, modeling electronics in SPICE (Simulation Program with Integrated Circuit Emphasis), writing reports for ARPA-E, laying out a printed-circuit board, preparing a patent application, or any combination of such tasks. And she gets to do those things in historic surroundings: a building in San Francisco's Mission District that once housed a pipe-organ factory. With antique organ pipes adorning the walls and aging hardwood everywhere, the building retains a turn-of-the-20th-century air. Other projects being pursued there include inflatable robots, form-fitting fuel tanks for natural-gas cars, and an electric cargo tricycle that lets the rider lean into turns.
The engineers at Otherlab have tried to preserve their building's Arts and Crafts aesthetic, foregoing steel desks for oak ones and using old library card catalogs in place of the usual plastic parts bins. Casual visitors could easily imagine they've wandered into the mad inventor's lair from a steampunk novel.
Even more pleasant than the ambiance, Madrone explains, is the nature of the people she's laboring alongside. “There's this cultural bias that if you want a hard-core engineering company, everyone's got to be intense and aggressive and arrogant and all of that," she says. “Here people are confident but not arrogant, and thoughtful instead of aggressive."
Best of all for her, though, is knowing that her designs could have a real impact. “I think a dream job is getting to work on something that is really relevant that you're passionate about every day," she says. “For me, that is what the dream is."
This article originally appeared in print as “Solar-Energy Innovator."