There is no universal cheapest hour to charge an EV. The answer depends on which kind of tariff you are on: on a flat tariff there is no cheap time at all; on a fixed time-of-use tariff the cheap window is set in advance, usually overnight; on a dynamic tariff the cheapest hour moves from day to day; and in a solar home the cheapest energy may be your own surplus in the middle of the day. Find your tariff type first — the hours follow from it.
Key Takeaways
- There is no universal cheapest hour; the answer is a property of your tariff type.
- Flat tariffs have no cheap time, fixed time-of-use tariffs have a set window, dynamic tariffs move daily, solar homes chase midday surplus.
- Your tariff document or supplier’s price feed is the only authoritative source for your hours.
- Once the window is known, hold the charge inside it with a schedule in the car or in a charger that states scheduling.
Four Tariff Types, Four Different Answers
| Tariff type | When charging is cheapest | How you know today’s answer |
|---|---|---|
| Flat (single rate) | Never — every hour costs the same per kWh | Your bill shows one unit rate; charge whenever it suits you |
| Fixed time-of-use | The plan’s off-peak window, typically overnight, sometimes with a midday shoulder | The window hours are printed in your tariff document and rarely change |
| Dynamic / hourly pricing | Whichever hours clear lowest that day — often windy or sunny periods, not always night | The supplier publishes prices ahead, usually day by day, in its app |
| Solar home on any tariff | While your panels produce more than the house uses | Your generation meter or inverter app shows the surplus as it happens |
Most general advice about “charging overnight” quietly assumes the second row. It is good advice for that row — and meaningless for the first, wrong on many days for the third, and backwards for a car that sits at home under working panels.
How to Tell Which Type You Are On
- Read the bill. One unit rate means flat. Two or three named rates with clock times means fixed time-of-use. A rate that references market or hourly prices means dynamic.
- Check for an EV-specific plan. Many utilities offer a dedicated EV tariff or an off-peak charging credit; the state incentives database at DSIRE and your utility’s own pages list what exists in your area.
- Ask what the average hides. The U.S. average residential price is 18.31 cents per kWh (EIA), but an average blends peak and off-peak together — your window prices are in your own tariff document, not in any national figure.
The Pattern Behind the Windows
Where windows exist, they follow demand. System demand usually troughs in the small hours and peaks in the early evening, when cooking, heating and cooling coincide — which is why fixed windows are usually built around the night and why dynamic prices so often dip when wind or solar output is high. Treat that as a pattern, not a promise: a hot evening, a calm night or a holiday can move the cheap hours, and only your supplier’s document or price feed is authoritative for your address.
Putting the Cheap Hours to Work
Once the type and window are known, timing the charge is a scheduling task: the schedule can live in the car (most EVs offer one) or in a charger whose maker states scheduling as a feature — check the exact model’s stated features before relying on the second. EVDANCE’s EV-ACS3210E is a 32 A Type 2 portable charger (single-phase about 7 kW, IP66) whose page states app control and energy monitoring; whether any charger’s app schedules a session is a line to confirm in that model’s documents, not to assume. The mechanics of schedules and windows are covered in smart charging and time-of-use tariffs, and the wider range is on the residential charging page.
Frequently Asked Questions
Is it always cheaper to charge at night?
No. Night is cheapest on a typical fixed time-of-use tariff. On a flat tariff it makes no difference, on a dynamic tariff the cheapest hour moves daily, and a solar home’s cheapest energy is its midday surplus.
Where do I find my exact cheap hours?
In your tariff document or your supplier’s app: fixed windows are printed there, and dynamic prices are published ahead, usually for the next day. No website can state them for your address.
Should I switch tariffs just for the car?
Compare the whole household, not just charging: a sharp off-peak rate sometimes comes with a higher peak rate that your other usage pays. Run the comparison on your last few bills before switching.
Related Reading
- Smart Charging and Time-of-Use Tariffs: How Scheduling Cuts EV Charging Costs
- Solar Panels and EV Chargers: How to Charge Your Car With Sunshine
- How Do Smart EV Chargers Work?
