The dirty secret of electric cars in 2026 is that charging at a motorway rapid can cost more per mile than petrol — around 80p/kWh, which on a typical car works out dearer than diesel. Charged the right way, though, an EV runs at about 2p a mile, a tenth of a petrol car. The whole economics of going electric hinge on where you plug in.
Here's the cheap-to-expensive ladder.
Cheapest: home, on an off-peak tariff
If you can charge at home, an EV-specific off-peak tariff is the single biggest saving available:
- Octopus Intelligent Go, OVO Charge Anytime, EDF GoElectric and similar offer a cheap overnight window — often around 7p/kWh versus a standard ~25p day rate.
- At 7p/kWh, a car doing 4 miles/kWh costs under 2p a mile.
- The car charges itself overnight in the cheap window; you wake up full.
This is where EV running costs actually beat petrol decisively. No home charger, no off-peak — and the maths gets much tighter.
Genuinely free public charging
It still exists, more than people think:
- Supermarkets — many Tesco (with Pod Point), Lidl, Aldi, and Morrisons car parks have free or cheap chargers while you shop. The Pod Point app maps the Tesco network.
- Some councils and shopping centres still offer free destination charging to draw footfall — slower (7–22kW) but free while you're parked anyway.
- Workplaces — a growing number install free charging as a staff perk. Ask.
Free charging is almost always slow (destination) charging, which is fine when the car's parked for hours regardless.
The apps that find it
- Zapmap — the standard UK charger map. Filters by speed, network, price, and availability. Shows which are free.
- Network apps — Pod Point, BP Pulse, Osprey, Gridserve — each runs its own pricing; subscriptions can cut per-kWh cost if you use one network a lot.
Most expensive: motorway rapids
Avoid rapid chargers except on long trips. At 60–85p/kWh they're the petrol-equivalent (or worse) end of the scale. Use them to top up on a journey, not as your default.
The honest ladder
| Where | Rough cost/kWh | Cost per mile* |
|---|---|---|
| Home, off-peak | ~7p | ~2p |
| Home, standard | ~25p | ~6p |
| Supermarket / free destination | £0 | £0 |
| Public slow/fast | 40–55p | ~12p |
| Motorway rapid | 60–85p | ~18p+ |
*Assuming ~4 miles/kWh.
The EV saving is real, but it lives almost entirely at the home-off-peak and free-supermarket end of the table. Charge there, treat rapids as the emergency option, and electric is the cheapest motoring in Britain. Charge mostly on rapids and you've bought a more expensive petrol car.