The government has brought forward a ban on sales of new petrol/diesel cars and vans to 2030. Is this enough to de-carbonise road transport? No, but not necessarily for the reasons you think.
Can we mine enough materials for vehicle batteries? Yes. More than enough lithium resources have been identified. Alternative battery chemistries, based on various combinations of elements, are also likely to be viable for vehicles.
Will the National Grid be able to cope? Yes. It requires investment, but there is no major obstacle to laying more cables, installing more substations, and rolling out ‘smart grid’ technologies to smooth out peaks of demand. Grid-connected batteries, for instance made up of retired vehicle batteries, can be recharged overnight and then used to rapid-charge vehicles during the day.
What about goods vehicles, buses and coaches? Electric buses are a mature technology. Shenzhen’s 16,000-strong bus fleet is electric. The UK has the second largest number in Europe – after the Netherlands. HGVs are more of a challenge because big batteries (to run long distances between recharging) mean a smaller payload. That will be resolved by technology and operating practices.
What about the carbon cost of manufacturing battery-electric vehicles? That is a problem while the energy required to manufacture cars and batteries is derived mainly from fossil fuels. As the global energy supply switches rapidly to renewables (which it has to, or we’re doomed), the carbon cost of manufacture falls. However, that does mean vehicle scrappage schemes will have to be carefully targeted in coming years.
The real problem is the huge carbon cost of continuing to use the petrol/diesel vehicles we have now and continue to manufacture. Biofuels do not help because they require land needed for food production and re-forestation (to re-capture and sequester carbon). Synthetic fuels are not the answer because their manufacture is highly inefficient and produces more carbon emissions than the fuels they replace.
There is, I’m afraid, one inescapable conclusion: we have to reduce vehicle-miles very significantly to stay within a carbon budget that may be safe. I’ll look at what this means in a future column.
This article was first published in the Cambridge Independent on 25 November 2020.
You can watch a presentation by Edward Leigh on How to De-carbonise Transport, given as part of the Cambridge Zero Climate Change Festival 2020: