Hydrogen city car hits 300mpg and 30g/km CO2

‘Open source’, locally manufactured fuel cell car designed for sharing 

With politicians and carmakers waxing lyrical about electric vehicles, the squat hydrogen fuel cell car with a top speed of 50mph introduced by start-up Riversimple in June is definitely bucking prevailing trends.

But what the Urban lacks in pzazz, it makes up in green credentials. Thanks to its super-light carbon composite body (just 350kg), fuel efficiency reaches an impressive 300mpg. It gives off no exhaust pipe emissions, and, says Riversimple, it’s also a ‘lower carbon’ car than the all-electric G-Wiz. The carbon emissions resulting from generating the electricity used to produce its hydrogen fuel work out, per kilometre, as half as much as those emitted in producing the power for the G-Wiz (30g/km as opposed to over 60g/km).

Riversimple’s lead engineer, former racing car driver Hugo Spowers, describes it as a first attempt at a “sustainable car” in the widest sense. That’s why Urban’s whole design and manufacturing process looks very different to your average car.

Firstly, it’s ‘open source’, which means design blueprints will be freely available for others to improve on. Secondly, the Urban won’t be sold outright, but leased to car sharing companies, local councils and individuals. ‘Sharing’ features, such as card-key door locks, are central to the design. And Spowers hopes to add a swappable dashboard so that different drivers can customise the same car with their own settings and driving stats. He reckons each car will have a 16-year life span, four times the average ‘leasing expectancy’.

Manufacturing will also be local and fairly small-scale. If Spowers is successful in finding the next $32 million in investment, he hopes to establish a site producing around 5,000 cars a year – possibly in Oxford.

Why hydrogen, you might ask. The fuel is not yet produced on a large scale without electricity from fossil fuels, nor is there existing infrastructure. “Hydrogen, in my opinion, is a massively better option [than electric batteries] for a city car,” responds Spowers. He explains that the Urban is not a fuel cell car in the same way as Honda’s Clarity FCX, which replaces a powerful internal combustion engine with a large (and expensive) fuel cell. Instead, it uses a small, 6kW fuel cell – perfectly adequate for the modest flow of power to the four wheelbased electric motors – and a bank of ultracapacitors, charged by a combination of the fuel cell and regenerative braking, to deliver brief bursts of high power for acceleration.

Spowers said Urban’s efficiency and range (200 miles compared with G-Wiz’s 75) mean drivers need refuel only once a week – so one hydrogen station could service scores of cars.

But will drivers be interested in sharing cars? Spowers thinks the idea of individually owned vehicles may be on its way out, especially if fun-to-drive cars like Urban can provide better city mobility. “We’re definitely taking the long view on this one,” he says. – April Streeter

2 July 2009

April Streeter