CG from Co Kerry, asks: “I have a 13-year-old 2.0-litre diesel. Am I better to drive this car into the ground than replace it with an EV since the amount of CO2 involved in making a new car and the use of lithium batteries may counter the extension of my old car’s life?”
Not really, no. The thing is that pretty much no matter how you crunch the numbers, an electric car will always produce fewer emissions over its lifetime than a petrol or diesel car.
In keeping an old car going you are, to be fair, stretching out the repayment time, if you like, of the emissions used to create that car. Equally, a new electric car has something of a double-whammy of emissions when it’s being built, because there are emissions from building the car, and then more emissions from building the battery – in fact, the battery bit almost doubles the total emissions from making the car.
However, once it’s been built, an EV will be so much lower in emissions even than an older car. In general, according to estimates by ecological think tank Transport & Environment, the emissions from a combustion car, including both its construction and its use, will average out at 246g/km of CO2 across its lifetime (official CO2 emissions figures only take into account emissions from driving the car and don’t include total well-to-wheel figures).
Your EV questions answered: Am I better to drive my 13-year-old diesel until it dies than buy a new EV?
Your EV questions answered: Is it okay to leave an electric car sitting for a while? For how long?
Can I really do a long journey in an electric car?
EV Q&A: Is it possible to reduce the environmental impact of building an electric car?
When it’s first made, assuming a worst-case scenario when it comes to emissions from the electricity and gas grids during its construction, a new EV is hovering at around the 50g/km mark for lifetime emissions. Using the most fossil-fuel-heavy electricity network for charging, that will expand to around 150g/km averaged over its lifetime – 100g/km to the good compared to a combustion car.
Using the best-case, renewable-heavy electricity scenario, that will increase to only around 55g/km averaged over the car’s lifetime.
That does not take into account the fact that many car makers now claim that their electric car production facilities are ‘carbon neutral’ – that’s debatable, as even with on-site solar and wind energy generation, those factories are still having to offset carbon emissions to meet this claim, because they still have to draw some energy from their respective national grids.
However, while the claim for carbon-neutral construction may be somewhat tenuous, or at least comes with a few large caveats, there’s another thing to consider: your 13-year-old car was built using 13-year-old power grids.
According to the World Economic Forum, in 2011 25 per cent of the European Union’s power generation came from coal, and another 19 per cent from natural gas, with a smaller five per cent coming from oil. In 2021, while natural gas had risen to 20 per cent of total generation, coal had dropped to 14 per cent, and oil had fallen to just two per cent. So your 13-year-old car was made with, on average, considerably ‘dirtier’ electricity than anything being built today.
There’s a further consideration and that’s reuse. Not of the car’s physical components – clearly, metals and plastics can be recycled and reused. No. Here we’re talking about fuel. No matter what you do, if you’re putting regular old fossil fuel diesel into your car and burning it, that’s it. It’s burned. You can’t recover it and recycle it and burn it anew.
[ EV Q&A: Why are there no lamp-post chargers in Ireland?Opens in new window ]
However, if you’re driving an EV right now, while it’s true that electricity grids aren’t perfect and therefore there’s a somewhat hidden CO2 cost to charging, it’s also true that you can power your car from renewables (by putting in some home solar panels, for instance) and it’s equally true that, unlike diesel fuel, when the battery of your EV comes to the end of its useful life (something that’s taking far, far longer than any of us expected when the first electric cars started to come to the market a decade ago) it can be recycled, almost to 100 per cent, and reused as a new battery for a new EV.
That’s the real beauty of electric cars when it comes to a circular economy and reducing emissions. Their effect rumbles on throughout and beyond their initial service lives. The batteries in today’s EVs will be, eventually, removed and used for static storage – which has its own CO2 reduction potential – and then when they’re done with that will be broken apart, stripped down and recycled.
Now, you’ve specifically asked about whether an EV would run up more emissions in build compared to just keeping your old car running, and even then the EV comes out on top. First off, an EV’s in-use emissions are utterly dwarfed by a combustion car’s. Secondly, your 13-year-old car, no matter how well you’ve looked after it, is unlikely to be as efficient as it was when new, so your actual emissions are probably higher than the original official figures.
So while you might think you’re saving emissions by running your old car into the ground, all you’re actually saving is some money. That is true – keeping an old car going is almost always cheaper than buying a new car. But when it comes to emissions, there’s only one winner. And it’s electric.
