The short answer is – it depends in which country you’re in.
In my last blog I noted:
“most importantly, low pollution electric cars are only viable if the electricity used is from sustainable sources, in particular renewable energy”
On this theme, this week the University of Michigan’s Transportation Research Institute published a study analysing greenhouse-gas emissions for electric vehicles (EVs) worldwide, taking into account the fuel used to generate the electricity in each country and give a (US) miles per gallon equivalent (by comparison a conventional new US car is 25.3 mpg).
Here in the UK for example, if you were charging your EV at 11:00 on the 7 November 2017, 51% of the energy surging into the batteries would have been a product of natural gas power generation – the remainder being 17% nuclear, 12% coal, 5% others and 15% renewables. But the sky was cloudy with little sun or wind – on other days, power from renewables can double (the UK has 6,500 wind turbines and counting).
But looking at averages and taking into account the British weather, the UK falls into a group of countries with an effective US MPG of 52-99. Other countries in this group include the US and Russia who are major users of natural gas. Hydro-powered Norway in the 1,000-5,100 band is one of the greenest, some 10-100 times cleaner than charging the same EV in the UK!
At the other end of the scale (29-51), the ‘dirty dozen’ include Australia, India and China, all massive users of coal. China is, however, investing huge sums in renewable energy and India is waking up to its escalating air quality problem.
Meanwhile, a report by the Australia Institute found that to meet its greenhouse gas emission reduction targets, Australia needs to achieve 66-75% renewable energy by 2030. In 2016 renewables accounted for about 4%.