Hydrogen city-car set for UK manufacture

The production prototype car, being built by Riversimple Engineering in Llandrindod Wells, Wales where the company has opened its new R&D headquarters, will be powered by a combination of hydrogen fuel cell and regenerative braking system.

It will be capable of travelling at up to 60 miles per hour, with an energy efficiency equivalent to 240 miles per gallon.

The car, which is being designed by Chris Reitz, previously design director at Fiat and Alfa Romeo, is equipped with an electric motor in each wheel to recapture energy from braking. The energy will be stored in a bank of super-capacitors to provide 80 per cent of the power needed for acceleration.

This means the fuel cell itself can be much less powerful, with an output of 8kW compared to the 85kW devices used in most prototype hydrogen cars, said Hugo Spowers, technical director and founder of Riversimple.

Consequently, the fuel cell will be much lighter, and with no gearbox or transmission system, the overall weight of the powertrain will be significantly reduced, said Spowers. “If the whole powertrain is lighter you can also have a much lighter structure, which has a knock-on effect in reducing the amount of power you need,” he said.

The car will be built with a strong but lightweight carbon fibre shell, he said. “We are aiming for a complete vehicle weight of 520 kilograms.”

Using a low power fuel cell also allows Riversimple to keep costs down, according to Spowers. That is because the cost of a fuel cell rises directly in line with the amount of power it produces, meaning doubling the output will double the cost of the device. “We can have a much simpler and cheaper fuel cell, which will still provide enough power for our car.”

The car will have a range of 300 miles, and be capable of accelerating from 0-50 miles per hour in eight seconds. The prototype will be built with funding from the Welsh government.

If the vehicle achieves certification and goes into production, Riversimple plans to build 5,000 cars each year, creating 220 jobs in the process. The company will retain ownership of the cars, which will be leased and reused. Customers will pay a single monthly fee covering the cost of the vehicle, as well as its maintenance, insurance and fuel, said Spowers.