THE BLOG

22
Jun

GETTING REAL ABOUT AIR POLLUTION

We loved a recent tweet about Riversimple Rasa “I’d rather be cycling behind one of these.”

Cyclists on British roads sit on the frontline of traffic pollution.  It’s pretty unfair really, since they are not the ones responsible for that pollution.

Being able to travel from A to B is a fundamental part of modern life.  But then again breathing good quality air is pretty fundamental too!  The evolution of the car is a marvelous story, but our love affair with the combustion engine is slowly coming to an end.  Cleaner cars are on their way.  Just take a look around a busy parking lot and you will see how rapidly we are shifting to alternative fuels – cleaner, greener, better.

At Riversimple we are 100% with that cyclist.  None of us want to breathe in a cocktail of pollutants that include nitric oxide and nitrogen dioxide; carbon monoxide, and the heavy particulates associated with smog.

RASA TECHNOLOGY

As with all battery electric and fuel cell electric vehicles, the Rasa emits zero nasty emissions at the tail pipe, but a recent report published by Peter Achten and Victor Timmers of Edinburgh University highlights the problem of particulate emissions.  These emissions can come from the tyres and brakes as well as engines.  In fact, now that filters are so good, even diesel cars emit more particulates from tyres and brakes than from the engine.  According to the Achten/Timmers report, because many electric vehicles are heavier than combustion-engined cars, they emit higher levels of particulates.
The Riversimple answer is to go deeper into the design.REAR QUARTER SMOOTHED

The Rasa is strong but light – less than a third of the weight of the Toyota Mirai hydrogen fuel cell car.  This minimises any particulate emission from the tyres, because emissions are proportional to weight.  But even more significantly, the braking system for the Rasa is primarily electrical, rather than dependent on friction.

There are only two instances when the Rasa production model will rely upon friction brakes:

–           emergency stops, anything over 0.3g

–           below 5mph, when there is not enough braking torque

So the only regular release of brake particulates would be when braking at speeds below 5 mph.  However, as our engineers will tell you, the quantity of particulate release from friction braking is proportional to the kinetic energy of the car when you start braking.  At 5mph, the kinetic energy of the car is less than 0.7% that at 60mph.  In other words, particulates not a problem.

SURVIVAL OF THE FITTEST

In the wild, animals have a deep- seated ability to react to stimulus.  And in the longer term whole species can adapt to change through the process of natural selection.  It’s a simple, obvious thing – organisms that do not react, do not survive for long.

A similar ability to react is needed in industry.  Air pollution levels are unacceptable and some levels recorded are breaking regulations.  Changing the regulations, put there to protect our health, is no solution.

The businesses that are fittest for the times will survive and thrive.  Great news for people who breathe air.  Bad news for dirty, polluting industries with their heads still stuck in the sand.

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