A few fuel cell powered cars are now in the hands of consumers. These include the BMW 750hl and Honda FCX that were produced in limited quantities for use in real world demonstrations. Now, they could be joined by another limited production fuel cell vehicle called the Riversimple Urban Car from a small company in the UK.Unlike the luxurious fuel cell cars from major automakers, the Riversimple is meant for urban duty only. Riversimple also has a unique business model. Borrowing from the ‘open-source’ concept found in the computer software world like LINUX, Riversimple will put all the designs, specifications, and other information about this vehicle online so the design can be used and improved upon by anyone.
The diminutive Riversimple is a two seater that’s about the same size of a smart fortwo. Its low 770 pound weight is achieved by using a carbon fiber composite body and eliminating heavy mechanical parts. The 6 kilowatt fuel cell powers electric hub wheel motors in each wheel. In comparison, the Honda FCX Clarity has a 100 kilowatt fuel cell to move its greater mass.This design decouples cruising and acceleration with the fuel cell supplying only the level of power needed for cruising at a constant speed. Most of the braking is done by each electric wheel motor acting as a generator to slow the vehicle down. Braking energy recouped by the efficient regenerative braking system is stored in ultracapacitors that provide acceleration power on demand. Incorporating ultracapacitors means the fuel cell only has to be large enough to supply about 20 percent of the power needed for acceleration. This also helps keep both weight and costs down.
The Riversimple has a top speed of 50 mph and a range of about 240 miles on just 2.2 pounds of hydrogen. The company says it has an efficiency equivalent of 300 mpg and emits less than 30 CO2/km based on a life cycle analysis.
Oxford and Cranfield Universities have collaborated in the car’s design and Horizon Fuel Cell Technologies provides the fuel cells. The two universities and Riversimple, through its OSCar Automotive Ltd. subsidiary, were also involved in developing the Morgan Motor’s fuel cell LIFECar concept.Riversimple will lease the cars in Europe over 20 years instead of selling them, with fueling included in the lease cost. The cost of the lease is expected to be about US$330 per month. A total of 10 prototypes are in the works and the company hopes to partner with a city to develop a hydrogen infrastructure. The project has been financed by Sebastian Piech, the grandson of Ferdinand Porsche.
The open source design for the Riversimple Urban Car will be stored on the 40 Fires website (www.40fires.org), where this project vehicle is identified as the ‘Hyrban.’ Any small manufacturer will be able to lease the design for free or for a nominal amount, modify it as desired, and build its own version. The idea is that car manufacturing jobs can be created within the communities where the vehicle is used. Produced locally in 5,000 to 10,000 unit quantities, this innovative strategy could substantially reduce the carbon footprint associated with traditional centralized car manufacturing and distribution.
