From the NY Times article:
But the least-expensive methods of hydrogen production use fuels like coal or natural gas, and those create pollution, experts say. Hydrogen is also difficult to ship and store. In addition, power from fuel cells is far more costly than the same amount of power from a gasoline engine.
“Real revolutions have to occur before this is going to become a large-scale reality,” said one of the report’s authors, Dr. Antonia V. Herzog, a staff scientist at the Natural Resources Defense Council. “It very possibly could happen, but it’s not a sure thing.”
The report said battery-powered cars or hybrid cars, which use gasoline and electric motors, could turn out to be better choices. And over the next 25 years, the effects of hydrogen cars on oil imports and global-warming gas emissions “are likely to be minor,” the report said.