2012-06-22

How A Young Physicist Is Making Solar Power Work, Even When The Sun Is Down

Danielle Fong might have dropped out of grade school, but that hasn’t stopped her and her company LightSail from finding a way to potentially drastically change how much power we can get from renewable energy.

It is not unreasonable to expect that the renewable energy collected by the world’s solar panels and wind farms is being stored somewhere, ready and waiting to power our microwaves and hairdryers at a moment’s notice. Bad news: mostly, it’s not. Sure, there are a few methods in practice—expensive batteries that degrade over time, a medieval-sounding technique that involves pumping water up and down a hill—but by and large, if there’s a lot of wind blowing but not enough lightbulbs to use it, that energy simply goes to waste.

Hopefully, that’s about to change. Danielle Fong is the chief scientist (and grade-school dropout) behind LightSail Energy, a Berkeley-based team that’s developing compressed-air technology to store the power we don’t use, and return it to the grid when needed. It’s a simple concept: Just use the electricity generated by your solar panel and/or windmill to power a compressor, pushing air into a tank. When you want your energy back, you release the air out of the tank, and use it to drive a generator, creating electricity. "That’s the basic idea," says Fong. Sadly, there’s more bad news again.

Compressed-air technology has long struggled with efficiency—the heat energy generated via compression has always gone to waste—and that’s the almost part where LightSail’s greatest innovation swoops in. Fong was researching compressor-powered vehicles when she had her eureka moment: "It became clear that what you wanted to do for maximum efficiency was keep the temperature as close to constant as possible in compression and expansion," she says. "It turned out nobody had figured out how to do that, and I read a Wikipedia article saying it was impossible to do it, and I said, ‘My god, that’s not true. You can just spray water in.’ And then I was like, ‘Wait. I could just spray water in.’ And thus the company and core idea was born."

What does spraying water in do? Best to let the genius explain: "Instead of wasting the heat, we collect it by spraying water into the air during the compression process," she says. "That keeps the temperature down, and it keeps the pressure down, so you have to put less energy in to compress the same amount of air. During expansion, spraying water sends heat back into the air, which keeps the pressure high, and increases the amount of energy you get back." Science aside, the numbers don’t lie: LightSail’s process recovers 70% of the energy it puts out, pretty much doubling the efficiency of the standard compression method. "Eventually, we’re going to replace all of the energy requirements of the world," says Fong. "Or so we plan. The world has a way of turning out with surprises."

Indeed, surprises abound in Fong’s story, starting with her decision to bail on middle school at the age of 12. Her precocious worldview was shaped via reading everything from astrophysics textbooks to A Confederacy of Dunces, as well as through video games like Sid Meier’s Civilization and Alpha Centauri, where, as she puts it, "I would take responsibility for the future of the world over and over again." A big influence was SimEarth: The Living Planet. "It is notably hard over eons to keep the climate of SimEarth stable," she explains. "My Earth kept dying. So I gained a visceral awareness of the interconnectedness of all these different life systems, and as a result, I think I questioned whether or not we were doing the right thing." By 17, she’d graduated from Dalhousie University in her native Halifax, Nova Scotia. From there, she was accepted to the PhD program at Princeton’s Plasma Physics Lab, where she decided the whole hot fusion thing was taking way too long, she had no interest in the academic model of writing (and being rejected from) grant applications, and she wanted to start changing the world now. "I don’t see why people should waste time," she shrugs.

Having set out to earn enough money to fund her independent research, Fong was working a brief stint at a video game company in 2008 when she met up with a PhD physicist named Steve Crane. Something clicked, and three months later, the two had founded LightSail; three years later, they had all the kinks worked out, and were ready to start the production phase of development. They plan to deliver their first shipping-container-sized units in late 2013. And after that? World domination, of course. "We’ve talked a lot about different defining visions for the company," Fong says, "and one that’s always risen to the fore is this idea of democratizing energy: Providing energy how people want it, where they want it, and when they want it, at affordable prices for everyone."

Sound impossible? Fong doesn’t see why that should stop her. "The message I would like to put forth is that there are great innovations in ways to do things that are sort of right under people’s noses," she concludes. "And if they opened their eyes and worked towards it, it might not take too long before we live in a much greater world. This is a neat trick: If you don’t feel confident enough to say something is possible, you can say, ‘Well, is it impossible?’ Try to prove that it is not impossible, and in so doing you can show the way."

This piece is part of Change Generation, our series on young, change-making entrepreneurs. Read the rest here.

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