Most industrial hydrogen today comes from blasting natural gas with steam, a process that also releases carbon dioxide. A Penn State team last week proposed using solar energy-powered nanotubes to split water into hydrogen and oxygen, a process called electrolysis, in the journal Nano Letters, but such ideas remain experimental for now.
The big surprise for the study authors, says Crane, was how much technological progress has occurred since 2002 in making fuel cells more efficient, longer-lived and more durable. The last technological hurdle is storing hydrogen in a car, he says, where current technologies pressurize the gas up to 10,000 pound-per-square-inch, something that takes a lot of energy. Remember the Hindenburg? Crane says past studies have found that safety isn't a big concern with hydrogen as a fuel, despite its fearsome reputation. "Gasoline has a lot of problems too," he says. "Hydrogen dissipates, it doesn't pool under your car and combust."
The report concludes by calling for government research into all sorts of alternative-fuel technologies to cover its bets. A mixture of energy efficiency, biofuels and eventually, hydrogen, could lead to fuel cell cars going from $100,000 vehicles today to the affordable ride of tomorrow.