Technology

Clean Slate

Riversimple began with a hydrogen fuel cell, a manifesto for sustainable design and a blank sheet of paper. Every aspect of our technology is continuously interrogated for simplicity, efficiency, lightness, strength, affordability, safety and sustainability. And the name of our first model, the Rasa is a nod to that blank sheet of paper – Tabula Rasa means ‘Clean slate’ in Latin.

The prototype Rasa on Penybont Common, 2016.

The Rasa is an electric car powered by hydrogen rather than batteries and emits water. The hydrogen passes through a fuel cell, where it combines with oxygen from the air to produce electricity. This electricity flows to small, lightweight electric motors, one in each wheel, which give the car 4 wheel drive.

Lightness

The carbon fibre chassis of a Rasa weighs just over 70 kgs.

The two-seater Rasa Beta weighs 654kg. As a comparison the original Smart Fortwo weighed 730kg and the latest battery electric version weighs 1095kg.

Lightness is key to efficiency and range. We have used a combination of technologies to keep the weight to a minimum and deliver the greatest fuel efficiency and superb environmental performance. Like Formula One cars it is built with strong and lightweight composite materials rather than steel.

The Rasa is designed to do the equivalent of 250 mpg and with a range of 300 miles, which would last most people a week of local travelling before needing to refuel.

A Combination of Technologies

We are using a small fuel cell to provide cruising speed power, and supercapacitors for fast acceleration. 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 the super-capacitors and is sent back to the motors, allowing acceleration from 0 to 60 in just 9.5 seconds. Our unique Axle Guardian software monitors safety-critical powertrain features at all times.

The only battery onboard the Rasa is there to power the control units to start the car and turn on the lights before the fuel cell is switched on.

We’ll be as open as we can be with our technology and our standards. Riversimple will be implementing an open-source framework to encourage a faster and more collaborative elimination of environmental harm while also reducing the overall costs for all who implement the technology.

The Rasa is a two-seat car specifically designed for everyday local, suburban and rural journeys. With its spacious interior, the car is suitable for the daily commute and a trip to the shops. Other vehicles in Riversimple’s pipeline are a two-seater van and five-seater family vehicle. Click here if you’d like to join the waiting list for any of these models.