Ponzi and I had a rare opportunity to learn more about hydrogen fuel-cell vehicles with one of the automobile industry's leading minds, Dr. Lars Peter Thiesen.

The GM HydroGen4 is the European version of the Chevrolet Equinox Fuel Cell. In fall 2007, the first of these fuel cell cars -- a global fleet of more than 100 vehicles is planned -- will be on the roads in the USA.

The HydroGen4's fuel cell stack consists of 440 series-connected cells. The entire system produces an electrical output of up to 93 kW. With help from a 73 kW/100 hp synchronous electric motor, acceleration from zero to 100 km/h takes around 12 seconds. The front-wheel drive vehicle's top speed is around 160 km/h.