Despite the recent buzz, they still have a couple of big obstacles
Fuel cells—battery-like devices that convert natural gas, hydrogen or other gases into electricity—have long been seen as a promising technology. But also a flawed one. They’re expensive to make, tend to degrade over time and lack the kind of infrastructure to effectively replace gasoline in vehicles.
The recent media blitz around Silicon Valley-based Bloom Energy Corp. has raised the buzz level about fuel cells. But despite some encouraging signs, many observers remain skeptical about any imminent breakthrough.