Mercedes-Benz F600 Fuel-cell concept

Mercedes has been running a test fleet of fuel cell A-classes since 2002, and it’s preparing for small-scale production of a fuel cell B-class in 2010. To get an idea of what the fuel-cell B-class will be like, CAR has spent some time on the road with the curiously-named F600 HyGenius fuel cell concept, first seen at the Tokyo show in 2005.

Ah yes, fuel cells are… erm, remind me, would you?

The fuel cell combines hydrogen and oxygen in a chemical reaction which generates electricity, with water as a by-product. The carbon dioxide emissions of the vehicle are zero, which makes it sound like the ultimate green car – but those environmental credentials take a hit when you consider the electrical energy consumed by the production of hydrogen in the first place.

What’s special about the F600’s stack?

The F600’s fuel cell stack is smaller, more powerful and more economical than previous generations of the technology. It’s housed under an A-class-style ‘sandwich’ floor along with the drive motor, hydrogen tank and a lithium ion battery, which stores excess energy from the fuel cell and captures ‘waste’ energy through regenerative braking. As a result the centre of gravity is low and there’s still family-sized space inside.

What’s it like on the road?

Wide doors open out and up to make entry easy. Generous glass area, a flat floor and the hum of the electrics out back make F600 feel like a glazed golf cart, albeit one which features a leather-clad interior with heated (or cooled) cup-holders.
Driving it isn't as alien as you might expect. Push the familiar-looking START button on the dash and it settles into a subdued whistle as it idles. Four buttons next to the steering wheel mimic auto gearbox modes: select D for drive and the F600 answers the accelerator with a brisk surge forwards as the fuel cell and battery work together to deliver up to 115hp. There’s no multi-ratio gearbox, so progress is uninterrupted by gearchanges. A distant electric-tram hum and the whine of the electric 'turbocharger’ which supplies air to the fuel cell stack are all but drowned out by the rustle of wind around the A-pillars as the speed builds.

F600 is impressive for its utter lack of fuss: it goes and stops on demand, just like any production car. MB's boffins are understandably protective of their multi-million-euro testbeds, but they treat this one with a nonchalance that speaks volumes. It doesn't need to be babied. As a forerunner of next-generation fuel cell vehicles, it’s impressively competent and effective.

Verdict

F600 feels cohesive and complete, but turning hydrogen fuel cell cars into a practical proposition means more than just engineering advanced on-car systems. A whole infrastructure for hydrogen distribution has to be established, which brings with it a raft of concerns over safety and evaporative emissions. And economic, sustainable production of hydrogen depends on a plentiful supply of renewable electricity to make it viable. Providing that will take more than simply the efforts of a car maker or two.