You might reasonably argue that the case for electric vehicles is overwhelming. Trust me – 10/15 years from now you’ll pass a petrol station and think “wow, haven’t seen one of those in ages”.

So why haven’t we all already got an electric car? There are huge tax breaks, they cost hardly anything to run, they’re great to drive (if you haven’t tried you really must). Is it the range? Is the charging network? Is it the higher list price? There are around 198 thousand BEVs and PHEVs registered in the UK – out of just under 37 million vehicles – that’s less than half a percent.

My thanks to Dr Colin Herron CBE for the time he’s spent discussing the likely causes with me, which seem to come back to the lack of supply of BEVs and PHEVS. A major issue here may be the availability of batteries and the chemicals used to make them. Arguably – we can’t make a serious dent on worldwide car consumption without a major increase in the volume of low cost batteries and a change to battery technology – and that’s, by many estimates, 8 or more years away.

Take Cobalt – estimates vary of how much is in each battery, with Tesla seemingly using the least. NMC811 chemistry would suggest roughly 6.9 kg of Cobalt in each 66 kwh battery (I’ve heard much higher estimates for current batteries). In 2018 we dug up 140,000m tonnes of Cobalt globally (64% of that in the Congo). So – assuming we didn’t make anything else with it – that’s enough to make around 20m vehicles a year with an average battery size of 63 kWh.

We’d need around 11% of that 2018 total just to cover all new UK car registrations. We have a challenge to match mine output with battery production, as the mines are having to predict the chemical composition of the batteries to ensure production is economically viable. A second consideration is that a large mine takes up to 10 years from concept to full production.

And yet the batteries just keep getting bigger – the latest from Audi, Mercedes and Porsche are all 70-90 kWh, and I’m guessing use a lot more Cobalt. Consider this – you can make as many as 10 PHEVs with the Cobalt required by 1 Audi e-tron. Maybe we should be focusing tax incentives on technologies that use smaller batteries until the battery supply has normalised.