BMW has developed a 1 series hatchback which uses hydrogen hybrid technology. According to specifications, it uses a 5kW fuel cell to power an 82kW (109 horsepower) motor. The fuel cell will store electricity in a bank of ultracapacitors. It also has a conventional internal combustion engine. The electric motor which is powered using the hydrogen fuel cell will be used in city driving, while the internal combustion engine, using regular gasoline, will come into play under hard acceleration.

This is a very brilliant idea by BMW which utilizes the environmental benefits of using hydrogen fuel cells without compromising on performance.
[wired]