Electric cars are only as green as their energy supply. A Tesla electric car, for example, can be eco-friendly in Norway but not the US – due to the fact that in the former country, the car will be powered by electricity that is generated by hydropower; while in the US, most of the country’s electricity comes from the burning of fossil fuels. Now while this may also (partly) apply to Riversimple’s hydrogen-powered car, it is still a worthy contender as a sustainable vehicle. Indeed, they are certainly superior in many ways to electric cars.
Riversimple’s hydrogen-powered car
Riversimple state on its website that its hydrogen-powered Rasa car:
has been created and interrogated for simplicity, efficiency, lightness, strength, affordability, safety and sustainability.
But how exactly do you power a car with hydrogen? Well, as the company elaborates:
The hydrogen passes through a Proton Exchange Membrane in the fuel cell where it combines with oxygen to form water and electricity. The electricity then flows to the motors in each wheel. These motors are small, lightweight and give the car 4 wheel drive.
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 a bank of super-capacitors at the front of the car. Unlike a battery, these super-capacitors can take a huge charge very quickly, but they don’t store a lot of energy. The energy they take in is sent back to the motors again and provides the energy to accelerate.
Sustainability is a main concern of Riversimple. It believes that the vehicles we should drive should be truly sustainable – in the company’s own words: “Less sustainable is still not sustainable”. Riversimple adds that its purpose is “To pursue, systematically, the elimination of the environmental impact of personal transport.”
The most sustainable car in the world?
The Rasa is able to capture wasted energy from braking and reuse it, and this – combined with the fuel cell – enables the car to achieve 250 miles per gallon. Furthermore, as a renewable hydrogen infrastructure grows, Riversimple’s car could end up becoming the most sustainable car in the world. Already the Rasa emits nothing but water.
Hydrogen-powered cars also seem to be far more practical than electric cars. As The Guardian reports:
Hydrogen cars can travel more than 300 miles on a single tank and refuel in minutes, similar to refuelling a petrol car, whereas today’s EVs take several hours to charge.
Now, it should be emphasised that, like with electric cars, the eco-friendliness of hydrogen-powered cars depends on the specific kind of electricity grid in place. However, the Rasa car outcompetes the Tesla car in a number of ways. Hugo Spowers, inventor and founder of Riversimple, points out:
It takes five minutes to fill a car with petrol. A Tesla is 30 minutes with a supercharger, and that’s to 80% [charged]. So for a motorway services with 20 petrol pumps, you’d need to replace them with 120 chargers to get the same throughput of cars. Each Tesla charger is 120kW, so that means you’d need a 14.4mW substation – the equivalent of powering 32,000 homes in the UK.
And Oliver Franklin-Wallis at The Guardian highlights:
Solar and wind power are intermittent, which is why governments are piling money into grid storage technologies. Therein may lie hydrogen’s advantage: it can be produced using excess renewables energy at peak time, then stored in tanks or underground caverns.
On a more political note, Spowers is slightly worried about what Brexit means for his company. Riversimple has been awarded a €2m grant from the EU in order to carry out testing. But now that the UK has voted to leave the EU, this grant will disappear. Moreover, not all of the evidence is in favour of hydrogen cars as the most efficient type of vehicle. Many different factors – such as major changes to funding, technology, and infrastructure – will help determine whether hydrogen-powered cars or electric are the way forward.
About the author: Sam Woolfe @samwoolfe
Sam is a freelance writer who is particularly interested in space exploration, sustainability, tech, and agriculture.