In defence of electric vehicles: carbon emissions

I’ve written a couple of articles recently about electric cars and some of the common criticisms of them. In particular, I’m interested in the ‘friendly fire’ criticism from environmentalists who overstate the problems in order to champion public transport or cycling. But in so doing, they play into the hands of the fossil fuel industry and the car companies, who’d like change to progress as slowly as possible.

Previous posts have looked at waste batteries and roadside emissions. Today I want to look at the carbon emissions from charging EVs, and the suggestion that if an electric car is charged on the grid, it’s little better than petrol or diesel.

For example, the second rate documentary Planet of Humans included a segment on electric cars, taking a press tour back in time to 2008 to comment on the Chevy Volt being charged from a coal power station. It’s hardly representative 12 years later, but it highlights the point that what charges EVs matters. An electric car that is charged on renewable energy is using zero carbon fuel – though it still has embedded carbon from manufacturing. An EV charged with coal or gas is obviously making a much smaller difference.

So the carbon emissions from charging electric cars depend on the local grid – assuming people aren’t charging it from their own solar panels. And here’s how that looks across Europe:

As you can see, the embedded carbon doesn’t change in this graph – although there are things you can do to reduce the embodied carbon of cars. But the lifetime emissions from charging vary immensely. Cars charging on nuclear power in Sweden and France achieve the lowest emissions. Countries with growing rates of renewable energy, such as the UK, are in the middle. Poland performs worst, with its high coal dependency.

But here’s the main message – even in Poland, an EV is 29% better than a fossil fueled vehicle. Electric traction is efficient enough to overcome a dirty grid.

That won’t always be true everywhere, and that study only runs the maths for Europe. This broader study from Nature Sustainability looks at a wider range of locations, and concludes that electric vehicles will have lower carbon emissions 95% of the time – including in China and Russia. India is an exception, though the calculations are from 2015. A second key message is that the benefits of EVs are not fixed, but improve as the grid they charge on shifts towards clean energy. Just because EVs may not be better in India right now, they soon will be and that’s no reason not to adopt them.

It’s also worth pointing out that national statistics aren’t enough, especially in a big country. A study from the US found that driving an EV in the Western United States would have dramatically lower emissions that in the East. Closer to home, running an EV in Scotland will have lower emissions than in England, because of Scotland’s abundant wind power.

So do electric vehicles still cause carbon emissions? Yes, depending on who’s driving what and where. But if will still be better for the climate, and it will get better in future.