With the good Doctor having addressed some of the realities of electricity supply and the practicalities of charging electric cars in Issue 391 “How it Works”, it’s not inappropriate for us to take a look at the cost side of the subject in this column. How, in the vastly different world of electric power, might we look to squeeze “the extra mile” out of every pound that is spent on charging electricity? In looking at the real-life fuel costs of going electric, we should be aware of some basic facts and realities that are too easily glossed over in the euphoria of what appears to be low cost fuel, and cheap motoring.

Not many people may perhaps realise that the level of VAT imposed on domestic electricity is just five per cent, whilst for nearly all business users the level is twenty per cent. So, if you buy your charging electricity out on-the-road from any sort of commercial fast charging unit, you are going to pay 14.3 per cent more for your electric energy than when charging up at home, even before supplier overheads and profits are included. That’s the equivalent of 18.6p per litre more on a litre of diesel at £1.30. Even allowing for the bulk buying discounts that businesses tend to get, your home charging electricity is, by a decent margin, the cheapest electricity you can buy to charge your car, and any free charging facilities will usually have hidden costs and significant strings attached. 

Furthermore, if you should choose to take on an Economy 7 type tariff, involving installation of a suitable meter, probably a smart one, then from around 11pm to 7am, the cost per kWh is set considerably lower. The daytime units may cost you a bit more than on a simple flat rate tariff, but the night charging rates can be as low as just 8p per kWh, when paired with a daytime rate of around 16p per kWh, and a fixed daily standing charge. Whilst all that cheap off-peak electricity is on offer during the night, few people are out on the road and needing to charge up, but we have yet to hear of any providers offering cheap rate fast charging during these low-cost night hours. 

So it seems that it is possible to get charging electricity at home overnight for as little as 10p per kWh (we have seen as low as 8.7p/kWh quoted), which compares with the range of 20 to 30p per kWh that is the general picture for fast on-road charging. You will need quite a lot more hours on charge with your 7kW home charger to top up with 40kWh of energy, for a typical 130 miles day’s motoring – maybe six hours, while you’re in bed asleep. It makes little difference to you though, with the aid of your charging timer, and you’re certainly going to get “the extra mile” out of your money by doing it with such cheap energy. Plus, you’ll be setting off on your travels without worries about battery range, and the problem of finding a costly fast charger that’s available and working. 

Looking at these comparison cost figures as costs per mile, we might pay just £4.00 for 40kWh of electricity with overnight home charging, against maybe as much as £10 to £12 for the daytime on-road fast charging. Based on our hypothetical 130-mile driving day, night home charging costs are under 3p a mile, whilst with costly fast charging it is as much as 8 to 9p a mile. That’s much the same sort of cost per mile that an economical diesel car, covering 63 miles on a gallon of diesel, can deliver. It’s a thought well worth dwelling on! But did anyone ever imagine that motorway fast charging electricity, just like their diesel and petrol, their cold drinks, and their awful sandwiches, was going to be anything but vastly overpriced? And that’s without any added taxes on charging electricity, which are more than likely to come in time. The Government will need to recover the lost revenue somewhere from petrol and diesel, to balance the books in the future.