EV Time-of-Use Plans: When TOU Charging Saves Money, and When It Doesn't

Most utility websites pitch time-of-use plans the same way: "Charge overnight and save." What they don't tell you is when the math reverses. A typical 12,000-mi/year EV driver on a moderate-spread TOU plan saves about $166/year at 90% off-peak charging — but the same driver charging only 30% off-peak pays $137/year more than they would on a flat rate. The line where TOU stops helping and starts hurting sits between 50% and 60% off-peak, depending on your utility's specific rate spread.

That break-even point is the single most important input on the decision, and almost nobody publishes it. So we ran the math at four charging patterns, two representative rate structures, and a national-baseline kWh consumption figure. Here's what TOU actually does to your annual EV charging bill.

The Baseline: What a Flat Rate Costs

An EV doing 12,000 miles a year at the EPA-typical 30 kWh per 100 miles consumes about 3,600 kWh/year for home charging. At the EIA national residential average of $0.16/kWh (May 2026), that is $576/year in charging costs. This is the number every TOU plan has to beat.

Two notes on the baseline. First, the 30 kWh/100mi figure is conservative — a Model 3 RWD does it on roughly 24 kWh per 100 miles, a Model Y on 28, an F-150 Lightning on 49. Bigger vehicles consume more, so the absolute dollars scale with the EV you actually drive. Second, the $0.16 average masks enormous state variation. Washington residents pay closer to $0.11; Californians pay over $0.32; New Englanders pay $0.27-$0.30. The percentage savings TOU offers stays roughly similar across those states; the dollar magnitude does not.

Two Representative TOU Structures

Residential TOU plans for EV owners fall into roughly two camps:

• Moderate-spread plans — a typical 2-tier residential TOU, with off-peak rates around $0.10/kWh and peak rates around $0.24/kWh. These are common at investor-owned utilities in the Midwest, South, and Mountain West where flat rates already sit close to the national average. The peak premium is meaningful but not punitive.
• Aggressive EV-specific plans — dedicated EV charging programs with off-peak rates around $0.07/kWh and peak rates around $0.25/kWh. Several utilities including DTE (Michigan), Xcel (Colorado), Duke (North Carolina), and ConEd (New York) offer dedicated EV charging riders with discount overnight rates. These are designed specifically to incentivize off-peak EV charging and have wider spreads than the standard residential TOU options.

Both rate ranges are representative of public utility filings as of 2026; specific plan rates change frequently. Your utility's actual numbers belong on a search of DOE AFDC's utility incentives database or directly on your utility's website — but the math below works on whatever rates you find when you check.

The Math at Four Charging Patterns

The percentage of charging you actually shift to off-peak hours is the variable that decides everything. Here is the annual cost at each pattern, against the $576/year flat-rate baseline:

Moderate-spread TOU plan ($0.10 off-peak / $0.24 peak)

Aggressive EV-specific TOU plan ($0.07 off-peak / $0.25 peak)

Two readings come out of these tables.

First, even on the aggressive EV-specific plan, break-even sits at 50% off-peak charging. If you can't reliably shift at least half of your kWh to overnight or weekend windows, you are paying for the privilege of being on a TOU rate. Below 30%, the loss runs $130-$140/year on top of higher charging costs the rest of the time.

Second, the upside on a moderate-spread plan is modest — $166/year at near-perfect 90% off-peak compliance. The upside on an aggressive EV-specific plan is twice that ($259/year at the same compliance), but the floor is the same. Choosing the right plan only matters if the off-peak discipline is there in the first place.

What Determines Your Off-Peak Share

The 70-90% off-peak share — the band where TOU clearly wins — is achievable if a few conditions line up:

• You own a Level 2 charger. A 240V/40A wall unit refills 30-40 miles of range per hour, so a typical day's driving (33 mi/day at 12K mi/year) tops up in about an hour of overnight charging. That is trivially within most utilities' 9 PM–6 AM off-peak windows. A 120V trickle-charger (Level 1) at 4-5 mi/hr cannot keep up unless you start at 100% range and never deplete it — you bleed into peak hours to make up the gap. Our panel capacity check tells you whether your home is ready for Level 2 without a service upgrade.
• You can schedule charging. Almost every modern EV (Tesla, Hyundai/Kia, Ford, Chevy, Rivian) and every smart Level 2 charger (ChargePoint, Wallbox, Emporia, Tesla Wall Connector) lets you set a charge window. Set it to start at the off-peak transition (typically 9 PM or midnight) and end at the morning transition. Don't override. The savings are entirely behavioral.
• Your daily driving is regular. Predictable commuter usage is the ideal TOU customer profile. Drivers who occasionally need a fast top-up before an unscheduled trip — rideshare drivers, sales reps, anyone with bursty long-distance days — will bleed kWh into peak hours and erode the savings.
• You don't have solar. Solar production peaks at midday, which is typically peak or mid-peak hours on TOU plans. Households with rooftop solar usually do better on a standard net-metering rate than on TOU, because TOU peak pricing applies to net imports during the exact window when their solar is offsetting the most. There are exceptions in states with aggressive solar export devaluation, but the general pattern holds.

If three of those four are true for you, TOU charging is the right play. If two or fewer are true, the math probably says stay on a flat rate.

Three Cases Where Flat Rate Wins

The "TOU always saves" framing breaks in three predictable scenarios:

• The 120V renter. Apartment dwellers on Level 1 charging from a standard 120V outlet typically need to charge whenever they're plugged in, which often spans peak hours during evening usage. Without Level 2 hardware they can't move 100% of charging into the off-peak window in a reasonable time. Stay on the flat rate.
• The split-shift household. Two-vehicle households where one EV is charged overnight and the other is charged during the day (work-from-home spouse, swing-shift schedule) push roughly half their kWh into peak hours regardless of intent. The math we ran at 50% off-peak share is what these households actually live in.
• The high-electricity-baseload home. TOU plans in most utilities apply to all usage, not just EV charging. If your household has a heat pump, electric water heating, electric cooking, and a pool pump — and you can't shift a meaningful share of that consumption to off-peak — the peak rate hits everything, not just charging. The EV savings can be eaten by the rest-of-house penalty.

The first two cases are the most common. The third matters more for highly-electrified homes in cold climates.

How to Actually Pick the Right Plan

The decision sequence is short:

1. Find your utility's TOU rate filings (usually on a "rates" or "electric service" page; sometimes under "for EV owners"). Note the off-peak rate, the peak rate, and the time windows.
2. Look up your current flat-rate kWh price on your last bill.
3. Compute your off-peak share honestly. Look at when you've actually charged for the last 30 days using your charger's app or the EV's logs. If your charger can't tell you, assume your share is lower than you think — most drivers overestimate by 10-20 percentage points.
4. Run the four-row table above with your specific rates. If your honest off-peak share lands above the break-even row, switch. If not, don't.

Two utility-side details to verify before you switch: whether the TOU rate has a seasonal change (many plans shift peak windows in summer vs winter), and whether there is a minimum bill or demand charge on the TOU rate that isn't on the standard rate. Both can quietly subtract from the savings you computed.

Why This Connects to the EV vs Gas Decision

In our recent three-comparison synthesis, electricity rate sat behind only the cross-shopped gas car's MPG in importance. The math there ran at the EIA national average of $0.16/kWh — the flat-rate baseline. A buyer on a 90%-compliant aggressive EV TOU plan effectively charges at an blended rate around $0.088/kWh, which cuts annual fuel cost from roughly $576 to $317. Over five years, that is a $1,295 swing in the EV's direction.

That swing isn't enough to flip the Prius case (where the hybrid won by $11K) or the RAV4 Hybrid case ($13K). It is enough to widen the Tesla-vs-Camry margin from $3K to roughly $4.5K, and to bring the 35-39 MPG mid-tier into closer EV territory. If you are running the EV vs gas calculator and your utility offers an EV-specific TOU rate that you can actually comply with, model your blended rate explicitly. The default $0.16 baseline understates the EV's case for that subset of buyers.

For everyone else — the renters, the split-shift households, the people who can't reliably move charging to overnight — the default $0.16 rate is correct, and TOU is a distraction. Use the time you would have spent comparing rate plans to look up your state EV incentives instead. The dollar amounts there move the decision more.

Methodology Notes

All charging-cost figures assume 12,000 miles/year at 30 kWh per 100 miles (3,600 kWh/year), the EIA national residential average flat rate of $0.16/kWh (May 2026), and the two representative TOU rate structures cited above. Rate structures are based on publicly filed residential and EV-specific TOU tariffs as of early 2026 from a non-exhaustive sample of U.S. investor-owned utilities; your specific utility's rates will differ, but the four-row table reproduces on any rate pair. We assumed flat off-peak/peak rates for arithmetic simplicity — many real plans are 3-tier (off-peak/mid/peak), which slightly narrows the savings band at near-perfect compliance and slightly cushions the penalty at low compliance. The directional conclusions are robust to that change. For methodology behind the cost-comparison series this post extends, see the methodology page.