riversimple's rasa fuel cell electric car tested on UK roads

riversimple’s hydrogen fuel-cell electric vehicle prototype is launched with a claimed fuel economy equivalent to 250 mpg (0.9 l/100km). the ‘rasa’ car has a lightweight carbon-fiber monocoque shell, in-wheel electric motors, a bank of supercapacitors charged by braking-regeneration, while travelling up to a 300 miles (483 km) on just a 3.3 lb (1.5 kg) tank of hydrogen.

all images © riversimple

a road-legal two-seater electric automobile, riversimple’s ‘rasa’ is designed to meet the company’s strict lightness, strength, affordability, and safety requirements, while maximizing fuel economy and minimizing carbon emissions. taking the form of a low-slung two-seat hatchback, the electric car has a unique exterior design, with a vented hatch at the rear, gull-wing doors, projection headlamps at the front, plus fairing covering the rear wheels.

the electric vehicle’s interior appears to be refined, with a clean dash layout, a pod-style instrument binnacle, in a minimalist, attractive finish. according to the wales-based company, the car will is, ‘light to handle, responsive, and fun to drive’, with acceleration to 89 km/h (55 mph) in approximately nine seconds, hitting maximum speed at around 96 km/h (60 mph).

the ‘rasa’ works via hydrogen passing through a proton exchange membrane in the fuel cell where it combines with oxygen to form water and electricity. the electricity then flows to small, lightweight motors in each wheel, giving the car four-wheel-drive. when the car brakes, the kinetic energy, that is normally lost in the form of heat, is captured as electricity. as the car slows, this electricity floods into a bank of super-capacitors at the front of the car. unlike a battery, these super-capacitors can take a huge charge very quickly, but they don’t store a lot of energy. the energy they take in is sent back to the motors again and provides the energy to accelerate.

riversimple’s innovative network design means that it only requires a fuel cell big enough to provide cruising speed power, rather than acceleration. the ‘rasa’ can get more than 50% of its braking energy back, which is used to boost acceleration. the light-blue prototype is designed by chris reitz, former design chief for the fiat 500, and his team at their studio in barcelona.