It is worth doing your homework on energy company tariffs before you switch to an EV. Start by getting quotes from as many energy providers as you can - especially those providing energy from renewable sources. Energy companies are aiming to encourage off-peak charging - that’s when general demand across the country is low - and they’re doing this by offering attractive night-time rates.
Let’s look at some real costs and rough comparisons between charging an electric car and refuelling with petrol or diesel.
How much to charge?
At time of writing, Octopus energy is offering electricity at 5p per kWh off-peak (from half past midnight to 4.30 in the morning). It claims 100% renewable energy too. Therefore, to charge a KIA e-Niro with its 64kWh battery is just £3.20. Even using standard day rate for charging is still just under £13.
The e-Niro quotes a range of up to 282 miles but let’s use a more realistic 230 mile range. That’s 1.4p per mile (or 5.7p per mile at the higher daytime charge rate).
The cost at a public, rapid charging point will be around 30p per kWh which works our at 8.3p per mile.
Contrast this with petrol or diesel. The average cost per litre of petrol (again, at time of writing) is 126.6p. One gallon therefore costs £5.75. And if your car achieves 40mpg, it’ll cost you 14p per mile. Even with a super-efficient diesel managing 60mpg (average price 129.2p per litre), that’s still 10p per mile.
So charging at home off-peak costs a quarter of peak rate electricity and a sixth of the cost at a public charger, yet they are all still cheaper than using an internal combustion engine. It also means you don’t need to feel guilty about an occasional day-time top-up.
But what do I save?
Comparing the low tariff charging to the petrol car managing 40mpg and covering a typical 10,000 miles a year, the saving is £860.
Don’t forget…
You will need to factor in the one-off cost of installing a dedicated home charger. Costs can vary but you should be able to find one for around £450 (which includes the government OZEV grant). This of course would be off-set against fuel savings in your first year.
Summary
| EV off-peak | EV daytime | EV public charger | Petrol |
Pence per mile* | 1.4p | 5.7p | 8.3p | 14p |