The new car has four motors powered by a PEM fuel cell rated at just 6 kW, supplied by Singapore-based Horizon Fuel Cell Technologies. Such a small unit is in contrast to current vehicle installations, which are generally in excess of 75 kW because of the power required to accelerate from stationary. Riversimple’s solution is to use ultracapacitors for additional power, which can release their charge nearly instantly to provide the power needed for acceleration. The ultracapacitors are recharged by regenerative braking. The lightweight car has a range of 240 miles (390 km), and a top speed of 50 mph (80 km/h).

Riversimple is to distribute the engineering designs to the 40 Fires Foundation, a not-for-profit organization that is making the designs ‘open source’. The aim with this approach is to allow local manufacturing in small plants, with production runs of just 5000–10,000 vehicles per year. The agreement will be that if the designs are improved by a local manufacturer, those improvements will be sent back, so that Riversimple’s ‘network of manufacturers’ can contribute to the overall development of the product line.

The company says that the cars will be leased, rather than sold, at an estimated £200 (US$315) per month, including fuel and repair costs. The company hopes to have the vehicles in production by 2013, according to Hugo Spowers, the former racing car designer who conceived the Riversimple idea in 1999.

Riversimple has established a partnership with industrial gases company BOC to install hydrogen stations for the cars in the city where the prototypes are launched. Riversimple is apparently in talks with cities including Oxford and Worcester for the pilot demonstration.

The car cost nearly £500,000 (US$830,000) to develop in partnership with Oxford and Cranfield universities, as well as Amzel Ltd, Alan Docking Racing, and Element Energy. An earlier project initiated by Riversimple, through its subsidiary OSCar Automotive Ltd, was the LIFECar, a hydrogen fuel cell Morgan sports car.