A lot of Martin Roscheisen's peers in the solar industry aren't fond of him — and it's not hard to see why. The CEO of the thin-film solar cell manufacturer Nanosolar, Roscheisen says that he can sell solar panels at $1 per watt of electricity produced — a price that is competitive with coal, and far lower than what his competitors can do. The secret is that Roscheisen's company uses nanotechnology to cut the cost of manufacturing, producing roll after roll of thin-film solar panels in a process that looks like a printing press. Nanosolar, which is backed by Silicon Valley heavyweights like Google founders Larry Page and Sergey Brin, just entered commercial production, and it's not yet clear that Roscheisen's promises will pay off. But if Nanosolar really can make thin-film solar cheaply and rapidly, it could speed the day when solar power will be cheaper than fossil fuels — without subsidies. "There's no other company out there that meets our cost model," says Roscheisen. "[Competitors] have to doubt us — because otherwise it makes a joke of their business model."