Are EVs green?

Are electric cars really environmentally-friendly or in fact just as harmful as petrol or diesel cars?

By Michael Boxwell on July 18, 2011 11:57 AM

Electric cars may be promoted as ‘green’, but with electricity being generated in smoky, polluting power stations, are they really any better for the environment than a modern efficient combustion engine?

Here in the UK, the official measurement for the carbon footprint of a car is by measuring the emissions from the car itself. Of course, electric cars benefit unfairly here – they do not emit pollution at all. Yet this measurement is also inaccurate with combustion engine cars as well. If you add the carbon footprint for refining the oil into petrol and transporting it to the service station (what's known as a 'well-to-wheel' measurement), the true CO2 figure for petrol and diesel is around 21% higher than the official figures show.

Electric car owners typically charge their cars up overnight when demand for electricity is low. During this time, older and more inefficient power stations are usually on standby and electricity has a much lower carbon footprint than during the day. By charging overnight, electric cars are very efficient: the total CO2 impact is often around a third of the most efficient combustion engine cars available today.

Conversely, charge up during peak times, using electricity generated from an old coal-fired power station, the carbon footprint is much greater. Yet even then, it is still around 10% more efficient than the best petrol or diesel cars you can buy.

For more about electric cars' green credentials, including stats and figures, pick up a copy of Michael Boxwell's book The Electric Car Guide here.