Nearly every utility-rebate guide on this site mentions a time-of-use rate in passing — PG&E’s EV2-A, SDG&E’s EV-TOU-5, DTE’s EV rate requirement, Evergy’s TOU bonus, Tucson Electric Power’s mandatory enrollment. None of them stop to explain what a TOU plan actually is, how the math works, or the one detail that determines whether it saves you money or costs you more. Here’s that explanation, plus the real rate numbers from the utilities already covered on this site.
How a TOU rate plan actually works
A flat residential rate charges the same price per kWh no matter when you use electricity. A TOU plan splits the day into windows — usually off-peak (overnight), peak (late afternoon into evening, when grid demand from air conditioning and returning commuters peaks), and sometimes a partial-peak window in between — and prices each window differently.
PG&E’s EV2-A Home Charging plan is a concrete, verified example. Per PG&E’s own March 2026 tariff filing:
| Window | Hours | Summer rate | Winter rate |
|---|---|---|---|
| Off-peak | Midnight-3 p.m. daily, including weekends/holidays | $0.22558/kWh | $0.22558/kWh |
| Partial-peak | 3-4 p.m. and 9 p.m.-midnight | $0.42760/kWh | $0.39428/kWh |
| Peak | 4-9 p.m. | $0.53809/kWh | $0.41099/kWh |
Off-peak is less than half the summer peak rate on that plan. SDG&E’s EV-TOU-5 plan works the same way with different numbers — 9 cents/kWh overnight (midnight-6 a.m. weekdays, midnight-2 p.m. weekends/holidays) for a flat $16/month base fee, as covered in our SDG&E EV charger rebate guide.
ChargePoint Home Flex
- Minute-level app scheduling is exactly what makes a TOU plan's off-peak window usable without remembering to plug in at a specific hour.
- Qualifies for most California and Midwest utility rebate programs' pre-approved equipment lists, including PG&E's.
Try Prime free for 30 days — Amazon Prime members get fast shipping on a smart charger or a Wi-Fi smart plug for scheduling, instead of waiting out standard delivery while paying peak rates in the meantime.
The honest catch: a TOU plan can cost you more
Utility marketing for these plans leans hard on the advertised off-peak discount and says much less about how that discount is funded: the peak rate is priced higher than a flat rate’s single price, specifically so the off-peak rate can be priced lower. A household with fixed, unmovable usage pays more at that peak rate — there’s no way around it structurally.
Consumer-rate analyses generally put the break-even point around shifting 20-30% of total household usage into the off-peak window. EV charging is the easiest single load to shift, since a car sitting in the garage overnight doesn’t care which of those hours it actually charges. But if you run the air conditioner, laundry, or dishwasher during the evening peak window on top of charging the car whenever you happen to plug in — not specifically overnight — you can end up paying more under a TOU plan than you would have on the flat rate you left behind.
This is also why PG&E’s Empower EV program requires staying on EV2-A for a minimum of six billing cycles after automatic enrollment, as detailed in our PG&E EV charger rebate guide — it’s not a free trial you can back out of the next billing cycle if your charging habits don’t end up matching the plan’s assumptions.
Already-covered utilities with TOU-tied EV programs
| Utility | TOU detail |
|---|---|
| PG&E | EV2-A off-peak midnight-3pm; 6-billing-cycle minimum once auto-enrolled via Empower EV |
| SDG&E | EV-TOU-5: 9¢/kWh overnight for a $16/month base fee; no cash rebate otherwise |
| BGE | ~$120/year extra from Smart Charge Management plus its own EV-TOU rate, stacks with Maryland's state rebate |
| DTE Energy | $500 charger rebate requires 1-year EV time-of-use rate enrollment |
| Tucson Electric Power | Mandatory 2-year TOU enrollment as a rebate condition, separate from SRP/APS |
| Evergy | $250 standard rebate doubles to $500 with TOU enrollment |
That’s six different ways a utility ties its EV incentive to a TOU rate — a flat bonus for enrolling (Evergy, BGE), a mandatory condition (DTE, TEP), or the entire incentive itself with no separate cash rebate at all (SDG&E). See our EV charger rebate hub for every state and utility this site covers.
Making a TOU plan actually pay off
- Check whether your charger can schedule automatically. See our best EV charger apps guide — scheduling is the single feature that turns an off-peak rate from something you have to remember into something that just happens.
- Pull your actual usage data before switching, not just an estimate. Most utility account portals show hourly or half-hourly usage; that tells you whether your real peak-hour load (AC, appliances, unscheduled charging) is small enough for the off-peak discount to win out.
- Know the commitment window before enrolling. Six billing cycles (PG&E) to 12 months (common at other utilities) is the norm, not a grace period you can test and cancel.
- Combine it with our home charging cost guide to see the dollar-and-cents difference a 30-50% off-peak discount makes on a typical monthly charging bill.
The bottom line
A TOU rate plan is a real discount, not marketing fluff — PG&E and SDG&E’s own published rates both confirm overnight charging can run less than half of peak pricing. But the discount only shows up if your actual usage pattern matches the plan’s assumptions, and the plans that tie an EV rebate to TOU enrollment generally lock you in for a year or more. Check your utility’s specific numbers against your own usage before assuming the advertised savings are automatic.