It is powered by a hydrogen fuel-cell engine, which converts hydrogen gas into energy.

NPR: On the Road with GM's Newest Hydrogen Car

But a fuel-cell engine is more than a stack of cells.

ECONOMIST: Fuel cells hit the road | The

But if it is to become the Intel of the industry, making the components at the heart of the fuel-cell engine, it still has an awful lot of work to do.

ECONOMIST: Fuel cells: Intel on wheels | The

The other main joint venture, Ford-led Ecostar, takes the machinery from Stuttgart and fits it into electric motors, transmission and control equipment to make a fuel-cell engine that can turn the wheels of a car or a bus.

ECONOMIST: Fuel cells: Intel on wheels | The

Burns says a fuel-cell vehicle has one-tenth the number of parts of a traditional internal combustion engine.

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The technology isn't new-a patent for a hydrogen internal combustion engine was issued in 1928, and a 20hp fuel-cell tractor was demonstrated in the late 1950s.

FORBES: Magazine Article

"Lots and lots of things are happening that indicate a worldwide interest, and most of the knowledgeable people are convinced that the next-generation replacement for the internal combustion engine is going to be a fuel cell, " Roan said.

CNN: Bus showcases fuel cell technology