Everyone knows EVs cost less to run than petrol or diesel cars but it all depends on where and how you charge.
Charging at home
Charging at home from cheap overnight electricity is hard to beat for cost and convenience. As an example Octopus Go is a tariff for EV users only that offers 4 hours electricity for 7.5p per kWh between 00:30 and 04:30 each night. Using a 7kW home charge point means you can add about 28kWh to your EV each night – that’s enough for around 112 miles – assuming 4 miles per kWh* – of motoring for £2.10 – less than 2p per mile. Octopus Go does charge more for daytime electricity – 40p/kWh – that’s more than the current price cap (around 34p/kWh). So if you use a lot of electricity during the day then do your sums carefully to see if Go is for you. If Go works for you apply via this link and we’ll both get £50.
https://share.octopus.energy/loyal-whale-836
For comparison an average petrol car that does 50 mpg costs about 15p per mile for fuel.
Calculated from: average unleaded price 162.8 per litre * 4.546 litres per uk gallon / 50 mile per gallon.
Charging away from home
Charging away from home is far more expensive – there’s countless rates and networks and the charger you want to use may not even be working. Today a 50kW charger near me charges 40p per kWh. So using the same 28kWh as above that’s 40 p/kWh * 28 kWh /110 miles = 10p per mile
Honestly if we couldn’t charge at home I don’t think we’d have an EV.
Charging from Solar
If you have solar panels you can charge your EV for free – but it does take some effort on your part and if the weather changes unexpectedly it’s easy to end up charging using expensive daytime electricity which can quickly offset any savings.
There are home EV charge points that can automatically divert excess solar power into your EV – if you are fitting a new charge point and don’t have a battery system then could be worth considering. If you have a battery you don’t need to spend the money. Checkout ‘Charging an EV from Solar’
We’ve been charging from Solar since Apr this year when the battery was installed- here’s the numbers:
| Grid Charge kWh | Solar Charge kWh | Miles | Total Cost £ | Solar Saving £ | |
| Apr | 38.9 | 65.4 | 477 | 3.37 | 5.40 |
| May | 16.9 | 126 | 498 | 1.46 | 10.40 |
| June | 0 | 120 | 515 | 0 | 9.90 |
| July | 26.6 | 122 | 645 | 2.30 | 10.07 |
| Aug | 17.4 | 104 | 508 | 1.51 | 8.58 |
| Sep | 35.8 | 63.7 | 471 | 3.10 | 5.26 |
If we’d simply charged overnight all summer the total cost would have been £63.82. Using solar the total cost was £11.75, so we saved £52.07. Is it worth it? Only you can decide.
* Our e-Niro achieves around 4.0 – 4.5 miles per kWh in summer, in Winter it’s down to 3.3 – 4.0 miles per kWh. I use 4 miles per kWh as it’s an easy number to remember and good enough for us. Your mileage may vary – literally!