Electric cars are grabbing headlines at the moment, with several new launches from major manufacturers like Nissan and Mitsubishi. But their claims of ‘zero emissions’ simply don’t stack up.
We decided to test claims of zero emissions pitting three electric cars against our favourite Best Buy alternatives – we chose diesel models that we knew were pretty thrifty on fuel.
We compared the Suzuki Splash diesel with the Mitsubishi i-MiEV, the VW Golf Bluemotion with the Nissan Leaf and matched up a Smart diesel with a prototype Smart ED (Electric Drive).
Each of the pairings are roughly similar on size – but certainly not on price.
The expense of electric cars
At first glance, all three electric cars are expensive. Even with the government’s £5k grant, the cheapest of the three, the Mitsubishi, is more than twice the price of its diesel equivalent.
And all three have major drawbacks when it comes to limited range, slow charge time and limited places to recharge on the road.
So if you ignore the sizeable price tag and the practical limitations, those who are still keen-to-be-green must try and fathom out whether buying one will earn them tree-hugging brownie points, or whether they’d be better off with a good modern diesel. The answer is far from clear.
Indirect CO2 emissions
It’s true that there are no direct emissions from these cars. So using them in cities will certainly reap significant benefits for the city’s inhabitants, cleaning up the local air no end.
But because almost all electric car owners will use a conventional electricity supply to charge their motors, this will incur a carbon cost from burning fossil fuels.
The figure for the UK’s electricity mix is 544 grams of CO2 per kilowatt hour, according to the Carbon Trust. We used this figure to calculate the CO2 that’s emitted per kilometre, which is now directly comparable to conventional cars.
We found that charging the Nissan Leaf produces around 81 grams of CO2 per km, whereas the Volkswagen diesel Golf produces CO2 emissions of around 108g/km (according to our own lab testing). That’s a 25% reduction in CO2 using an electric car instead of a diesel equivalent.
There are more factors
The picture becomes even less clear when you consider that the results don’t account for the extraction, refining or distribution of fuel – whether it be fuel used in power stations, or fuel that comes out of the diesel pump – something pointed out by electric car expert Robert Llewellyn.
Plus, we have more work to do to establish the environmental cost of manufacturing these cars – both the electric ones with their resource-heavy batteries, and conventional cars with their ‘lean manufacturing’ methods.
One thing is for sure – the environmental benefits of electric motoring are less clear-cut once you’ve taken electricity production into account.
It’s this factor, along with the sheer difficulties with charging them, which led us to conclude that the time isn’t right for electric cars – yet. Here’s hoping renewable electricity production will catch up with the cars themselves.
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