Last reviewed: 2026-05-31 (UTC)
A time-of-use electricity plan changes your price per kilowatt-hour based on when you use electricity. Instead of paying the same rate all day, you usually pay less in some hours and more in others.
That can work well if you can move big flexible loads like EV charging, laundry, dishwashing, or some water heating into cheaper windows. It can work badly if most of your usage lands in the utility's expensive hours.
There is no universal peak-hours answer. Unitil's current residential example uses on-peak from 3 p.m. to 8 p.m. on weekdays. Rocky Mountain Power's Utah residential example uses 6 p.m. to 10 p.m. on weekdays. Con Edison adds a summer super-peak from 2 p.m. to 6 p.m. on weekdays. So the real question is not just "What are peak hours?" It is "How does my utility's schedule line up with my actual usage?"
This guide is informational, not utility, tax, or financial advice.
Quick answer
| Question | Practical answer |
|---|---|
| What is a time-of-use electricity plan? | A rate plan where your electricity price changes by time of day, and sometimes by season. |
| When is electricity usually cheapest? | Often overnight, early in the day, or on weekends, but the exact hours depend on the utility. |
| Are weekends always off-peak? | Often, but not always. Many utilities make weekends cheaper, but you still have to check the exact tariff. |
| Who tends to benefit most? | Homes that can shift EV charging, laundry, dishwashing, or some water heating out of the peak window. |
| Who should be careful? | Evening-heavy homes, households that cannot shift usage, and some solar or net-metering customers. |
| What should you compare before switching? | Your actual usage pattern, the exact weekday and weekend schedule, any seasonal changes, and any EV, solar, battery, or electric-home rate options. |
How time-of-use electricity plans work
Unitil says a standard residential rate charges one price for every kilowatt-hour no matter when you use electricity, while a TOU rate charges different prices depending on the time of day. That is the core difference.
Most TOU plans use some version of these pricing buckets:
- Off-peak, the cheapest hours, often overnight or on weekends.
- On-peak, the most expensive hours, when the grid is under more strain.
- Mid-peak, a middle-priced block between the cheapest and most expensive periods.
- Super-off-peak or super-peak on some plans.
That is why TOU is more than a simple day-rate and night-rate split. Southern California Edison shows that some residential TOU plans vary by season and can include off-peak, mid-peak, and super-off-peak periods. Con Edison shows that some plans also add a narrower summer super-peak window.
Why peak and off-peak hours vary by utility and season
Utilities set TOU windows around real grid conditions, not a universal national clock.
The U.S. Energy Information Administration says electricity load is generally lowest overnight, lower on weekends and holidays, and highest during summer afternoons. Con Edison also explains that supply costs move with weather, demand, and market prices. That is why utilities do not all use the same TOU schedule.
A few official examples make the point quickly:
| Utility example | Lower-cost period example | Higher-cost period example | What it shows |
|---|---|---|---|
| Unitil | Off-peak from 8 p.m. to 6 a.m.; all weekends and holidays off-peak | On-peak from 3 p.m. to 8 p.m. on weekdays | A utility can treat the full weekend as cheaper than weekdays. |
| Rocky Mountain Power (Utah example) | Off-peak outside the evening peak block | On-peak from 6 p.m. to 10 p.m. on weekdays | Some utilities target evening home-demand windows rather than mid-afternoon only. |
| Con Edison | Off-peak from midnight to 8 a.m. in summer | Super-peak from 2 p.m. to 6 p.m. on weekdays in summer | Seasonality can create a narrower and more expensive summer peak block. |
| SCE | Lower prices are typically early in the day, overnight, and on weekends | Time periods and prices also change by season on some plans | TOU can change by both rate design and season, not just by hour. |
That is why generic advice like "charge at night" is only a starting point. You still need your utility's exact schedule.
How to find your utility's peak and off-peak hours
If you want the real answer for your home, use this sequence instead of relying on a generic article or a neighbor's schedule.
1. Find the exact TOU page or tariff for your utility
Look for the rate-plan page, tariff sheet, or rate-plan finder for your utility. PG&E's rate-plan finder is a good example of what to look for: one place to compare TOU, EV, solar, and electric-home options against your household.
2. Check weekday, weekend, and seasonal differences
A plan with an on-peak window from 3 p.m. to 8 p.m. behaves differently from one that peaks from 6 p.m. to 10 p.m. Summer-only super-peak windows can change the answer again.
3. Look for a bill-comparison tool or calculator
Unitil tells customers to compare the TOU plan against the standard rate and makes it clear that some households are better off staying on the standard plan. If your utility offers a comparison calculator, use it before you switch.
4. Check whether your utility has a more specialized option
Some utilities separate whole-home TOU plans from EV, battery, solar, or electric-home rate paths. If your household has one of those systems, the default TOU option may not be the best fit.
5. Read the commitment rules before you enroll
Some plans lock you in for a year. Rocky Mountain Power's Utah residential option requires a 12-month commitment and includes a first-year guardrail so the bill does not run more than 10% above what it would have been on the standard plan.
Who can save with TOU, and who should be careful
The biggest TOU mistake is assuming it is automatically cheaper than the standard rate. It is not.
TOU usually works best for homes that can shift big flexible loads
TOU tends to fit best when the household has meaningful electricity use that is both large and flexible.
Common good-fit examples include:
- an EV that can charge after off-peak begins,
- laundry and dishwashing that can use delay-start settings,
- electric water heating or heat-pump water heating that can shift some load,
- and households that can move more flexible chores into weekends or lower-cost hours.
That is why TOU can be attractive in an electrified home. The more controllable kilowatt-hours you can move, the more likely the lower-cost periods matter.
Use caution if most of your usage lands in peak hours
If your home does most of its cooking, cooling, heating, laundry, and charging during the expensive window, TOU may raise your bill instead of lowering it.
Unitil is unusually direct about this. It says that if shifting most electricity use away from 3 p.m. to 8 p.m. on weekdays is not realistic, staying on the standard rate may be the better choice. It also warns that customers who do not reduce on-peak use may see no savings.
That caution shows up in other official plans too. Rocky Mountain Power includes both a 12-month commitment and a first-year bill guardrail. Utilities do not add those protections unless some households really can come out worse.
How EVs, heat pumps, and other electrified loads change the math
For many households, EV charging is the clearest reason TOU can work. An EV can add a lot of monthly electricity use, but it is also one of the easiest big loads to automate.
Rocky Mountain Power explicitly tells EV owners to delay charging until 10 p.m. when demand is lower. That is the cleanest TOU use case because the load is big, predictable, and usually easy to move.
Other electrified loads are more mixed:
- Dishwashers and laundry are usually easy to push later with delay-start settings.
- Electric water heaters and heat-pump water heaters can often shift some load away from the expensive window.
- Heat pumps and air conditioning are trickier because they are tied to comfort. Some homes can pre-heat or pre-cool, but not every household can avoid peak-hour HVAC use without sacrificing comfort.
That is why electrification alone does not guarantee TOU savings. Electrification creates bigger electrical loads, but the savings only show up if those loads are flexible enough to follow the cheaper hours.
If TOU is part of a broader electrification plan that may also require electrical work, Watt Wallet's electric panel tax credit guide is the best companion on the project-cost side.
Whole-home TOU vs EV-specific, battery, solar, and electric-home rate options
Before you enroll in the default whole-home TOU plan, check whether your utility has a better fit for your setup.
SCE publishes TOU options for EVs, batteries, and electric heat-pump systems for space or water heating. It also says eligible TOU customers with a heat-pump water heater receive an additional baseline allocation. PG&E similarly separates TOU, solar, EV, and electric-home paths in its rate-plan finder.
That matters because the best answer is not always the standard whole-home TOU option. An EV household, a battery household, and an all-electric home may not want the same rate structure.
Solar adds another layer. Unitil says its whole-house TOU option cannot be combined with net metering, while an EV-specific TOU path may still make sense in some solar setups. That does not mean solar and TOU never mix. It means you should not assume the default TOU offering is compatible with your rooftop system or your current export arrangement.
If your TOU decision sits inside a larger water-heating upgrade, Watt Wallet's heat pump water heater tax credit guide can help on the equipment-incentive side while you compare the utility-rate side separately.
What to compare before switching
Do not choose a TOU plan based on generic peak-hour advice alone. Use this checklist instead.
1. Compare your actual usage, not a generic household average
PG&E is right to frame this as an actual-usage question. A plan that works for one household may be wrong for another even on the same utility.
2. Check the exact weekday, weekend, and seasonal schedule
The difference between 3 p.m. to 8 p.m. and 6 p.m. to 10 p.m. can change whether dinner-hour cooking, cooling, and charging help or hurt you. A summer super-peak block can change the answer again.
3. Look for EV, solar, battery, or electric-home alternatives
Your utility may offer separate rate paths that fit your equipment mix better than the basic whole-home TOU option.
4. Read the fine print on commitment rules and calculators
Con Edison says customers who switch to its TOU rate must stay enrolled for one year. Rocky Mountain Power has a 12-month commitment plus a first-year bill guardrail. Some utilities also publish comparison tools that can help you test the switch before you commit.
5. Check solar or net-metering compatibility before you enroll
This is where households can get tripped up. A whole-house TOU option may interact differently with solar exports, a battery, or a separate EV meter than expected.
If you are weighing TOU as part of a broader home-upgrade budget, Watt Wallet's guide to comparing rebates, tax credits, and installer quotes is the best next read after this one.
Practical ways to make a TOU plan work
A TOU plan only helps if your behavior, automation, or equipment controls actually follow the lower-cost windows.
The simplest moves are usually:
- scheduling EV charging to start after off-peak begins,
- using delay start on the dishwasher and washing machine,
- moving hot-water-heavy tasks away from the most expensive hours,
- pre-heating or pre-cooling when your comfort and your rate schedule allow it,
- saving flexible chores for weekends if your plan treats them as cheaper,
- and checking your first few bills after the switch instead of assuming the plan is working.
The practical goal is not to optimize every kilowatt-hour. It is to move the biggest flexible loads first.
FAQ
Are time-of-use electricity plans worth it?
They can be, especially if you have flexible loads like overnight EV charging or delay-start appliances. But they are not automatic savings. If most of your usage stays in the expensive window, the standard rate may be better.
What are peak and off-peak electricity hours?
Peak hours are the periods when electricity costs more. Off-peak hours are the periods when it costs less. The exact times vary by utility and sometimes by season.
Are weekends always off-peak?
No. Many utilities make weekends cheaper, and Unitil treats all weekend and holiday hours as off-peak, but you still need to check your own tariff because not every TOU plan works the same way.
Are TOU plans good for EV owners?
Often, yes. EV charging is usually the easiest large electrical load to automate into cheaper hours. It is one of the clearest cases where TOU can make sense.
Can solar or net metering change whether TOU makes sense?
Yes. Solar, batteries, and net-metering rules can change both compatibility and economics. Some utilities also offer separate solar, EV, or electric-home rate options that may fit better than the default whole-house TOU plan.
How do I know whether TOU will save me money?
Compare your real usage pattern against the exact TOU schedule, then check whether your biggest loads can shift out of peak hours. If your utility provides a rate-plan comparison tool, use it before switching.
Bottom line
Time-of-use electricity plans can be a smart fit for electrified homes, especially when EV charging, laundry, dishwashing, or water heating can move into cheaper hours. They are not automatic savings, and there is no universal peak-hour schedule to memorize.
Before you switch, compare your actual usage against the exact TOU schedule, check for EV, solar, battery, or electric-home alternatives, and make sure the plan still works with the rest of your electrification roadmap.
If you are also trying to lower the cost of the equipment that would move into those off-peak hours, use Watt Wallet's heat pump rebates by state guide or browse the full incentives library.