Short answer: plug in overnight on an EV tariff. For a typical 7,000 miles a year that's about £13 a month instead of £48 on the price cap – a saving of around £400 a year for the same miles.
Based on 7,000 miles a year, a car doing 3.5 miles per kWh and 10% charging losses (2,200 kWh a year), all charged in the cheap window. Standing charges are left out because you pay them whatever you drive.
| Tariff | Off-peak | Cheap window | Per month | Per year | Saving vs cap |
|---|---|---|---|---|---|
| Utility Warehouse EV | 6.9p | 00:00–05:00, bundle required | £13 | £152 | £427 |
| EDF GoElectric | 6.99p | 23:00–06:00 | £13 | £154 | £425 |
| Intelligent Octopus Go | 8p | 23:30–05:30 + smart slots | £15 | £176 | £403 |
| Octopus Go | 8.5p | 00:30–05:30 | £16 | £187 | £392 |
| E.ON Next Drive Smart | 8.5p | 00:00–06:00 | £16 | £187 | £392 |
| British Gas EV Power | 9p | 00:00–05:00 | £16 | £198 | £381 |
| OVO Charge Anytime | 14p | Any time, car only | £26 | £308 | £271 |
| Standard price cap | 26.32p | No off-peak | £48 | £579 | – |
Rates checked September–October 2026 and rounded. Peak rates vary by region. Use the calculator with your own mileage and car.
Nothing else comes close. An EV tariff gives you a cheap rate for five to seven hours overnight and a normal rate the rest of the day. Charge the car in that window and your cost per mile drops by about 70%.
The catch is the peak rate. Some EV tariffs charge more than the price cap during the day, so if you work from home and run heavy appliances in the afternoon, check the peak rate as well as the headline. Our tariff comparison shows both.
A 5-hour window on a 7 kW charger adds about 35 kWh – roughly 120 miles. That covers most people's daily driving easily. If you regularly need more, a longer window (EDF GoElectric's seven hours) or Intelligent Octopus Go's extra smart slots help.
A granny cable adds only 8–10 miles an hour, so it can't fill much of a battery inside a cheap window – the rest gets billed at the peak rate. A smart charger costs £800–1,100 fitted, schedules itself into the cheap hours and usually pays for itself within two or three years for an average driver.
Topping up overnight keeps every kWh on the cheap rate and is kinder to the battery than running it low and fast-charging. Set an 80% limit for daily driving and go to 100% before long trips.
At 75–85p per kWh, rapid charging costs ten times an overnight tariff and is close to petrol per mile. Keep it for road trips.
If your car or charger isn't compatible with smart tariffs, Octopus Go and EDF GoElectric work with any car. And if a 100% renewable supply matters more to you than the very lowest rate, Your Co-op Energy is a member-owned supplier worth comparing – put its rate into the calculator to see the difference.
Plug in overnight on a time-of-use EV tariff. Off-peak rates of 6.9–9p per kWh are about a third of the 26.32p price cap, so the same miles cost roughly 70% less.
For 7,000 miles a year in a car doing 3.5 miles per kWh, about £13–16 a month on an EV tariff, or about £48 a month on the standard price cap.
Yes, but at about 2.3 kW it adds only 8–10 miles an hour, so you may not fit a full charge into a five-hour cheap window. A 7 kW charger adds about 25–30 miles an hour.
Yes. Every time-of-use EV tariff needs a working smart meter so the cheap hours can be billed separately. Suppliers usually fit one free.