As part of its EV Answers series of articles, the expert team at WhichEV take a look at a small commercial vehicles and the fuel cost differences from fossil fuel to public charging to ‘at base’ charging…
First, let’s consider range. If you recently decided to fill a 50 litre tank with petrol at £1.55 per litre, then it will have cost you £77.50. That is around 11 gallons and the average petrol vehicle will do around 36 miles per gallon – so that tank will get you just shy of 400 miles. Older, less efficient vehicle that spend most of their time at 20 mph in traffic will get closer to 30 miles per gallon, or even less – so a range of 330 miles for £77.50. Doing the calculation, we have a cost per mile with petrol of 19p to 23p.
You will find some chargers close to 50p per kWh, but maybe the price will be higher. We’ll use 60p for this cost calculation and imagine that you’re using a charger capable of delivering a steady 100kW. Filling a 61.7kWh battery like this, will probably get you to 80% in around 30 minutes, but the last 20% could take another 20-30 minutes as charger technology slows the process as the battery gets full.
Either way, you can pick up 61.7kWh of charge for £37.02. Most drivers do their miles in town and on smaller A roads, where you’re more likely to get close to 270 miles on a charge. To match the range of the petrol vehicle, you’d need to add up to 25% more charge – which would be another £9.23 for a total of £46.28.
Charging at Base
There are various ‘overnight saver tariffs’ to choose from. We will use 9.5p/kWh for 7 hours, but there are other deals available at the time of going to press. Local production from wind/solar as well as battery storage on site can also make a difference to the calculation.
Starting from empty at mid-night, you would pick up 49kWh at £4.65 and then you’ll need to finish with the last 12.1kWh at around 30p each once your overnight rate expires. That’s a total to fill up in one sitting of £8.28. You will need to pick up an additional 15kWh on the second evening – if you want to balance the ranges. That can be done overnight for £1.43.
Cost per mile
Another way to look at the same data, is to calculate the fuel cost per mile for driving 330 miles:-
14p Public Charging
2.9p Home Charging (E-On)
Before committing to an EV, do some calculations yourself and shop around for a good tariff that makes sense for your lifestyle. Prices are volatile, so our comparison is for guidance only.