The British company Riversimple has declassified its urban hydrogen car Rasa. The working title of the project is Mk2, because it is the second such device after a small concept Riversimple Urban Car in 2009. At that time, it was supposed to produce a car in a small series and rent it out, but there was no funding. After some time, the British revised the design, improved the technical parameters, and along the way tried to reduce production costs by optimizing the design.
The Austrian Christopher Reitz, former chief designer of Alfa Romeo and Centro Stile Fiat, is responsible for the appearance of the car. He is one of the creators of the current FIAT 500, worked for Audi and Nissan, is the author of the A2 and Micra interiors. At the heart of the Riversimple Rasa is a carbon fiber monocoque weighing just 39.6kg. Externally, the roof panels are made of various composites, and the total mass of the prototype is only 580 kg.
In the name of the company — Riversimple, there is a hint of the river and water / River /, as a symbol of mobility and purity, and the word simple (simple) reflects the main philosophy of the product — the minimum number of details possible. The interior is also quite simplified, but does not look cheap.
For its movement, the machine uses four electric motor-wheels with a maximum power of 14 kW and 160 Nm each. They are powered by a compact fuel cell unit with a power of only 8.5 kW. The buffer energy reservoirs are 120 lithium capacitors providing 1.9 megajoules of energy. This allows you to have peak power for a short time, while during normal operation the energy consumption is much lower. In the stopped state, the motor-wheels operate in the generator mode, providing a recovery efficiency of more than 50%.
Hydrogen for the electrochemical generator is stored in a tank under a pressure of 350 atmospheres, and its amount is only 1.5 kg. For comparison, Toyota Mirai tanks can hold five kilograms. However, thanks to the lighter weight and higher efficiency of its device, Rasa travels 483 km on a single charge. Narrow Michelin tires with ultra-low rolling resistance also contribute to this result.
Only water vapor comes out of the «exhaust» of this car, but by counting emissions along the entire chain of hydrogen production from methane, the authors of the car claim that CO2 emissions are only 40 g / km. The calculation of the conditional fuel consumption compared to gasoline shows a consumption of 1.13 liters per 100 km. At the same time, the dynamics of a hydrogen city car is sufficient — acceleration from standstill to 88 km / h in 9 seconds. The same speed is called «cruise». The maximum speed is not reported, but during the tests the prototype accelerated to 160 km / h.
Riversimple’s plans include a series of 20 test vehicles scheduled to launch in 2018. The tests have already been funded by the European Union and the Welsh government. More than a dozen companies act as partners in the Riversimple project in the project: fuel cells — Canadian Hydrogenics, monocoque — British company KS Composites, electric motors — also British Printed Motor Works, supercapacitors — Japanese, JSR Micro.