EV Time-of-Use Charging Savings
See how much an off-peak electricity plan saves over a flat rate when you charge mostly overnight.
What is a time-of-use plan?
Most utilities offer two kinds of electricity rates: a single flat rate all day, or a time-of-use (TOU) plan where overnight electricity is much cheaper and daytime is more expensive. EV owners usually save a lot of money on TOU because most home charging happens after midnight anyway, when rates are at their lowest.
The calculator blends your off-peak and peak rates by how much of your charging happens during off-peak hours.
Worked example
Driving 12,000 miles a year in a 3.5 mi/kWh EV uses about 3,430 kWh. On a flat $0.15/kWh plan that's $514. On a TOU plan with $0.08 off-peak, $0.15 peak and 90% of charging done off-peak: blended rate $0.087, total about $300 — saving roughly $215 a year.
How to actually get there
- Call your utility (or check their website) for a “time-of-use” or “EV” rate plan. Many now have EV-specific tariffs with off-peak rates as low as $0.05/kWh.
- Off-peak windows are usually 11 PM–6 AM on weekdays. Confirm yours.
- Tell your car (or your home charger) to start charging at the off-peak time. Every modern EV has a schedule option in the app.
- Daytime use (running the dryer, AC, etc.) on TOU gets more expensive, so plan around it.
TOU is great if you can shift most usage off-peak. If you have a remote job and lots of daytime electricity use (especially AC in summer), the math gets trickier — check your actual usage pattern before switching plans.
Frequently asked
What is a time-of-use (TOU) electricity plan?
A utility billing plan where the per-kWh price varies by time of day — typically cheap overnight (off-peak) and expensive during weekday afternoons (peak). For EV owners who can charge overnight, the off-peak rate is often half or less of the flat rate.
How do I know if my utility offers TOU?
Check your utility's website or call them — many have a dedicated "EV rate" or "time-of-use" plan. Most major US utilities offer at least one TOU option, though some have income or service-territory restrictions.
What is a realistic off-peak window?
Most TOU plans set off-peak as 9 PM–9 AM or 11 PM–7 AM on weekdays. Weekends are often off-peak all day. Confirm your specific plan — windows vary by utility and sometimes by season.
What if I use a lot of daytime electricity (remote work, AC)?
TOU can still win if at least 70–80% of your usage is off-peak. With heavy daytime AC or other big appliances, run the math both ways — some utilities let you simulate your bill on each rate before switching.
How do I schedule charging to happen off-peak only?
Every modern EV has a schedule option in the app or vehicle settings. Set it to start charging at the off-peak window. Most smart Level 2 chargers also have an app-based scheduler. Set it once and forget it.