Technology: hydrogen fuel cell
Range: 270 miles
On sale: n/a
Driven by: Will Nightingale,
What Car? consumer reporter
Think of a hydrogen fuel cell as a miniature power station. Oxygen from the atmosphere is combined with hydrogen (from a fuel tank) to produce electricity, which in the Honda FCX Clarity is used to drive a 100kW electric motor.
There's also a lithium-ion battery on board the Honda that captures energy from braking – which would otherwise be wasted – and feeds it back through the electric motor to maximise efficiency.
The major benefit is that the only tailpipe emission is water, so it's understandable why hydrogen fuel cells are widely tipped to solve many of our energy and pollution problems in the long-term.
> Honda FCX Clarity: click to enlarge
> Toyota Auris Hybrid: click to enlarge
> Toyota Plug-in Prius : click to enlarge
> Vauxhall Ampera: click to enlarge
> VW Electric Golf : click to enlarge
> VW Golf Bluemotion : click to enlarge
> The winning car, electric Golf: click to enlarge
> Jim Holder & Matt Sanger: click to enlarge
What impressed me most, though, was how quiet the car is on the move. I'm not kidding, I could hear my watch ticking at 40mph. There was only a very faint hum when the fuel cell kicked in, plus a bit of tyre noise when up to cruising speed.
So where does the hydrogen come from? Well, that's the stumbling block at the moment. Hydrogen is expensive to produce and store, and at the moment it's extracted from fossil fuels, such as natural gas.
The hope is that, eventually, the hydrogen will by sourced from renewable energy sources. And if that happens, fuel cell cars will effectively produce no harmful emissions, once manufactured.
Highlight of the car Just how amazingly quiet it is on the move - a big bonus of electric motors over petrol and diesel engines.
Highlight of the day Seeing Gordon Murray's tiny T.25 parked up next to an enormous electric Range Rover.