Time-of-use EV plans: when they save and when they backfire.

Every EV-friendly utility page tells you to switch to a time-of-use plan. About 30 % of EV owners who do end up paying more than on the standard rate. Here is the math behind both outcomes — and the 4-step test to know which side of the line your household falls on.

Anatomy of a TOU plan

The structure varies but most TOU plans break the day into three bands:

The savings opportunity is in the super-off-peak band — that's where Level 2 home charging belongs. The risk is the peak band, where running cooling/heating/cooking adds up fast.

When TOU works (4 scenarios)

1. Low-load EV household. Single or couple, ~600 kWh/month, EV does 60 % of usage. Shifting that EV usage to super-off-peak slashes 40-60 % of the bill.
2. Solar + EV pairing. Solar covers your daytime peak/off-peak baseline; the only meaningful kWh you import from the utility is overnight Level 2 charging at super-off-peak. Best-case economics.
3. Heat pump + EV in NEM 3.0 California. Run the heat pump during super-off-peak (or solar production hours) and the EV at super-off-peak; the heat pump uses 4× less electricity than gas resistance heating at the same time. Compounds the TOU advantage.
4. "Free nights" plans in Texas. Deregulated retail providers offering $0.00/kWh from 8 PM-6 AM. Even if the day rate is ~25 % higher than standard, the math works as long as ≥50 % of your usage is overnight.

When TOU backfires (5 scenarios)

1. Summer AC during peak hours. Central AC in Phoenix runs 6-10 hours/day, much of it during the 4-9 PM peak window. The peak surcharge can be $400/season — eating most of the EV savings.
2. Electric resistance heat (baseboard or whole-house). Heat can't be shifted to overnight. Peak heating hours match peak utility hours. Don't enroll in TOU until you switch to a heat pump.
3. Work-from-home household. Cooking, laptops, lighting and HVAC running during the day = high off-peak and peak usage. The savings on EV charging get cancelled by the surcharge on everything else.
4. Pool pump. Most pool pumps default to running 8 hours/day, often spanning peak hours. Reschedule to overnight before enrolling in TOU.
5. Day-rate surcharge > EV savings. Some utilities (e.g. SCE TOU-D vs standard) charge ~$0.04/kWh more on peak hours than the standard rate would charge for the same kWh. If you can't shift enough load, you're paying more, not less.

The 4-step test to know your answer in 7 minutes

1. Download 12 months of hourly kWh data from your utility (PG&E "Download My Data", Con Ed "Green Button", FPL "Energy Dashboard"). Most US utilities offer it as CSV.
2. Bucket each hour into peak / off-peak / super-off-peak using the TOU plan's schedule. A simple spreadsheet pivot does it.
3. Calculate "annual bill under each plan": sum(kWh × rate) for each band on the new plan; sum(kWh × $standard_rate) for the standard plan.
4. Add your projected EV charging entirely in super-off-peak (assuming you'll use Level 2 scheduling). Compare totals.

If TOU wins by <5 %, the gains are within noise and not worth the rate-change hassle. If it wins by >10 %, switch immediately. Most utilities let you switch back once per 12 months without penalty.

Level 2 home charging: scheduling matters more than the plan

If your Level 2 charger has scheduling built in (most do — Tesla Wall Connector, Wallbox Pulsar Plus, ChargePoint Home Flex, Emporia EV), the savings come automatically. If it doesn't, every modern EV (Model 3/Y/3-Performance, Mach-E, Ioniq 5/6, Bolt, F-150 Lightning) has scheduling in the dashboard. Set the start time to 30 minutes after super-off-peak begins (gives the utility a buffer for slightly off-clock meters) and the stop time as 30 minutes before super-off-peak ends.

Frequently asked questions

Sources: PG&E, SCE, SDG&E, Con Edison, Eversource, Duke Energy, TXU, Reliant rate cards (Q1 2026), EPA fueleconomy.gov for EV efficiency, EIA national price index May 2026. Last reviewed May 12, 2026.