How a fuel cell vehicle works

Toyota brought us our first taste of vehicle electrification with the Prius hybrid, and now petrol-electric and even diesel-electric vehicles (HEVs) are becoming commonplace.

The next steps towards lowering CO2 emissions and reducing our dependence on unsustainable fossil fuels are all-electric vehicles (EVs) such as Nissan's LEAF and range-extending plug-in hybrid electric vehicles (PHEVs) like Holden's Volt and the Mitsubishi Outlander PHEV.

But many car-makers – including Hyundai, Toyota and Mercedes-Benz -- are now banking on hydrogen fuel cell vehicles (FCEVs) being the holy grail in sustainable future mobility, because they can produce their own electricity from hydrogen and emit only water.

FCEVs generate electricity from hydrogen through an electrochemical process within a fuel cell stack, combining the best attributes of petrol- and battery-powered cars and resulting in a clean, long-range vehicle with fast refueling times.

Thanks to Hyundai, which earlier this year leased its first mass-produced Tucson Fuel Cell vehicle to customers in Southern California, here's how they work.