The single biggest saving in EV ownership is not the car or the charger - it is when you charge. Off-peak and EV-specific tariffs sell night-time electricity at half to a third of the standard rate. This guide explains the three tariff types, the real savings, and the one check to run before switching.
The three types
| Type | How it works | Typical night rate (2026) | Found in |
|---|---|---|---|
| Time-of-use (TOU) | Price varies by time block: peak, off-peak, sometimes shoulder | US: $0.08-0.15/kWh vs $0.25-0.45 peak | Most US utilities, especially CA, Northeast, AZ |
| Dedicated EV tariff | Very cheap night window (often 4-6 hours), higher day rate; some require a smart charger the utility can schedule | UK: 7-9.5p/kWh night vs ~26p day | UK (Octopus, OVO, EDF and others), some US and AU utilities |
| Dynamic / real-time | Price follows the wholesale market every half hour; occasionally goes negative | Varies; night averages often 10-15p or $0.05-0.10 | UK (Octopus Agile), parts of EU/AU |
What the saving looks like
For a driver covering 12,000 miles a year (about 3,400 kWh of charging):
| Tariff | Annual charging cost | Saving vs flat rate |
|---|---|---|
| US flat rate $0.17 | $583 | - |
| US TOU off-peak $0.09 | $309 | $274/yr |
| UK flat 26p | £892 | - |
| UK EV tariff 8p night | £274 | £618/yr |
Assumes all charging shifts into the night window - realistic, because every EV and smart charger can schedule it. Figures November 2026.
The catch: the rest of your bill
EV tariffs make the night cheap and the day more expensive. Whether you win overall depends on your whole-house usage, not just the car:
- Clear win: you charge 3+ times a week at home and your daytime use is modest. The EV load dominates the math.
- Check first: someone home all day, electric cooking at 6 pm, AC in summer afternoons. Run last year's usage through the tariff's calculator before switching.
- UK rule of thumb: if charging is 20%+ of your household kWh, an EV tariff almost always wins. Below 10%, it depends on the day rate.
How to switch well
- Pull 12 months of usage from your utility account (or smart-meter app).
- Estimate your EV add: annual miles ÷ your car's mi/kWh.
- Run both numbers through each candidate tariff's online calculator.
- Set the car or charger to the night window the day the tariff starts - scheduling is where the saving actually happens.
- If the tariff offers scheduled-by-utility charging (they control when in the night), that is usually the cheapest option of all, and fine for most drivers.
What to read next
Sources: published utility TOU schedules (US), UK supplier EV tariff pages, Ofgem price cap, November 2026. Tariff prices change; verify current rates with your supplier.