“We need to get more of these things out into the field,” says Rohlfing. “Right now, if I’m a utility or a grid operator and I want to buy storage, I want to buy something that comes with a 20-year warranty. The technologies we’re talking about aren’t at that stage yet.”

But they’re getting close. Another ARPA-E-funded project, Energy Storage Systems, or ESS, announced last November that it would install one of its iron-flow batteries as part of an Army Corps of Engineers microgrid experiment on a military base in Missouri. ESS has also installed batteries to help power an off-grid organic winery in Napa Valley — for that matter, so has Aquion. As more and more of these one-off experiments prove successful — and more of these new kinds of batteries prove their worth — the possibility of a battery-powered energy system comes a little closer.

But will batteries ever be, well, cool? That’s a harder question. Aquion’s Matt Maroon has been working in the field since 2002, soon after he left college. At conferences, Maroon was often the youngest person in the room by 30 years. He was sure he wouldn’t be “a battery guy” for his whole career.

Fifteen years later, he’s still a battery guy — but he’s no longer the youngest person in the room. More students are starting to get involved with batteries, and people are starting to take notice. “It’s still not as a cool as working at Apple,” he says. “But I think people recognize its importance and that kind of makes it cool.”

“Or I hope so,” he laughs. “I’ve got a 9-year-old daughter. So I’d like to work on something that she thinks is cool someday. That’s my ultimate goal.”