TOU Charges on Your Electricity Bill: What They Mean & How to Save
TOU stands for time-of-use. A time-of-use electricity rate charges different prices per kilowatt-hour depending on when you use power, with peak hours costing more and off-peak hours costing less. Your exact TOU schedule and rates depend on your utility and rate plan. If you see TOU charges on your electricity bill, those charges reflect when you used electricity, not just how much you used.
The average U.S. household now pays around $160 a month for electricity, and that number keeps climbing in many markets. Many homeowners ask what is a TOU rate the first time they see one on their bill. Once you know your utility's schedule, you can shift tasks like laundry or EV charging and lower your bill without cutting how much power you use overall.
What Are TOU Charges on an Electricity Bill?
If you see TOU charges in electricity bill details, your utility is pricing electricity based on when you use it. This is different from a flat rate, where every kilowatt-hour costs the same no matter the time of day.
During peak demand hours, usually late afternoon into evening, electricity costs more. During off-peak hours, when fewer people are pulling from the grid, it costs less. Some plans also include a shoulder or mid-peak window that sits between the two.
TOU rate schedules are set by your electricity provider and, for regulated utilities, are typically reviewed or approved by the state's public utility commission. According to the U.S. Energy Information Administration, each utility designs its own rate structure and files it for approval with its state's public utility commission. That is why your peak and off-peak hours depend entirely on where you live and which company serves your home.
Seeing TOU in electricity bill details usually means your utility has moved you to a time-of-use rate structure, either by default or because you opted in. TOU charges are easiest to understand when you compare the kWh used during peak and off-peak windows side by side.
How to Find TOU Charges on Your Bill
Look for line items labeled peak, off-peak, mid-peak, or super off-peak
Compare the kWh used in each time period
Check the per-kWh rate listed next to each usage bucket
Watch for seasonal rate changes or delivery and supply charges listed separately
What Is a Time-of-Use (TOU) Rate?
A TOU rate is an electricity price that changes throughout the day. You pay more during peak demand hours and less during off-peak hours. Some plans also add a shoulder or mid-peak period that falls between the two.
Time-of-use pricing, sometimes called TOU pricing or a time-of-use tariff, works the same way: it charges a different rate depending on when you use electricity rather than one flat price all day.
A time-of-use rate can help flexible households save, but it can raise costs for homes that use most of their power during peak hours. For a deeper breakdown of how these plans are structured across the country, EnergySage's guide to time-of-use rates is a solid resource.
It helps to see how a TOU rate compares to the other common electricity pricing structures.
Rate Type | What Changes | Best For |
Flat rate | Same price per kWh all day, every day | Homes with little schedule flexibility |
Tiered rate | Price increases after you cross a monthly usage threshold | Lower-usage households |
TOU rate | Price changes based on the time of day you use power | Homes that can shift usage to off-peak hours |
Example: How TOU Pricing Changes Your Bill
Usage | Rate | Cost |
10 kWh during peak hours | $0.40/kWh | $4.00 |
10 kWh during off-peak hours | $0.15/kWh | $1.50 |
In this example, shifting 10 kWh of use from peak to off-peak hours saves $2.50. Actual rates vary by utility, season, and rate plan, so check your own bill for the numbers that apply to you.
That's a fixed example. For your own usage and rates, use our TOU savings calculator further down this page.
When Are Peak Hours Under Time-of-Use Rates?
Peak times happen when your neighborhood's overall electricity demand is highest. For most utilities, that means weekday afternoons and evenings, especially in summer when air conditioners are running everywhere at once.
Your exact peak window depends on your utility and rate plan. Some set peak hours from 4 to 9 p.m. Others use a shorter window, like 5 to 8 p.m., or a different schedule entirely.
Signs You're in a Peak-Pricing Window
It's late afternoon or early evening
Your neighborhood's overall demand is high
HVAC, cooking, laundry, or EV charging overlaps
Your utility app or bill shows a higher rate period
It's a hot summer weekday
When Are Off-Peak Hours for Time-of-Use Rates?
Off-peak times happen when demand drops off. This is usually overnight or early morning. Some utilities also offer a midday off-peak or super off-peak window in areas with high daytime solar generation. Your utility sets the exact hours, and they often shift a bit between summer and winter.
Running your dishwasher, washing machine, or EV charger during these windows can lower your bill without cutting how much electricity you use overall. Small shifts in timing add up over a full billing cycle.
If you have solar, your monitoring app can help show when your system produces the most power and when your home pulls from the grid instead. Our solar billing guide walks through how to read that data alongside your utility bill.
Pros and Cons of TOU Billing
Whether a TOU rate saves you money depends on when your household uses electricity and how much of that usage you can shift away from peak hours. It also depends on your appliances and whether you have solar or a battery.
Pros of TOU Rates for Your Home
Save money during off-peak hours by shifting laundry or dishwashing to cheaper times
Build more mindful energy habits over time
Reduce strain on the grid during its busiest hours
Get more value from a home battery by charging it during cheap hours and using it during expensive ones
Save on EV charging by plugging in overnight
Real-world results back this up. A Department of Energy case study of Oklahoma Gas & Electric's two-year SmartHours pilot found that customers with programmable thermostats reduced peak demand by about 30 percent, while participants overall saved an average of more than $150 on their summer bills.
Cons of TOU Rates at Home
Harder to manage if your schedule is fixed during peak hours
Air conditioning can drive up costs since it often runs during the hottest, priciest part of the day
EV charging gets expensive fast if it isn't scheduled for off-peak hours
Solar without a battery may not fully offset evening peak rates, since panels produce less power right when prices rise
Rate structures can be confusing to track without help from your utility's app or website
Wondering if your solar and battery setup lines up with your utility's peak hours? The GreenLancer team can help you check. Complete the form below to get started.
How to Tell If a TOU Rate Will Save You Money
Find your utility's peak, off-peak, and seasonal rates on your bill or account portal
Review your hourly or 15-minute usage data if your utility provides it
Add up how much electricity you use during peak hours right now
Identify flexible loads you could shift, like EV charging, laundry, or dishwashing
Compare your estimated bill under the TOU schedule with your current rate plan
If you have solar, compare production and export timing with the rate schedule
If you have a battery, factor in usable capacity, round-trip efficiency, and the peak/off-peak price gap
TOU Savings Calculator
Want the numbers without doing the math yourself? Use our calculator below.
Who Saves the Most With a TOU Rate Plan?
Not every household benefits equally from a TOU rate plan. Your savings depend mostly on how flexible your schedule and appliances are.
Homeowners Who Typically Save
EV owners who can charge overnight
Battery owners who can discharge stored power during peak hours
Remote workers with more control over daytime energy use
Solar homeowners paired with battery storage
Households using smart thermostats or app-controlled appliances
Homeowners Who May Not Save
Households with most of their usage packed into the 4 to 9 p.m. window
Homes running heavy air conditioning through the evening
Anyone who can't shift laundry, dishwashing, water heating, or EV charging to off-peak hours
What Is a TOU Rate Plan? Real Utility Examples
TOU windows vary by utility, season, location, and specific rate plan. Always confirm your current schedule directly on your utility's website before changing your habits around it.
Here is a quick look at example residential TOU plans from six major utilities. Most of these utilities offer more than one TOU option, so treat this as a starting point rather than the full picture.
Utility | Typical Peak Hours | Typical Off-Peak Hours |
4 to 9 p.m. daily (E-TOU-C) | All other hours, including overnight and midday | |
4 to 9 p.m. daily, or 5 to 8 p.m. weekdays depending on plan | Overnight, plus a winter midday super off-peak window | |
8 a.m. to midnight, every day (higher in summer, plus a weekday summer super-peak add-on from 2 to 6 p.m.) | Midnight to 8 a.m., every day | |
Weekday afternoons and evenings, varies by state | Overnight discount period | |
4 to 9 p.m. daily | Midday and overnight super off-peak windows | |
2 to 7 p.m. weekdays, June through September | All other hours |
PG&E's E-TOU-C plan, for example, lists peak pricing from 4 to 9 p.m. every day, with all other hours priced lower as off-peak. Even neighboring utilities in the same state can set different windows, so it always pays to check your own plan directly.
TOU Rates and Solar: What Homeowners Need to Know
Solar panels usually produce the most power in late morning through mid-afternoon. Many TOU peak windows fall later, in the early evening. That gap is a big reason solar alone does not always fully offset TOU charges in electricity bill totals.
Without a battery, your system may still pull expensive grid power right when your panels slow down for the day. Pairing solar with battery storage lets you store cheap daytime power and use it during peak hours instead. Under California's NEM 3.0, export values vary by time, which can make battery scheduling more important for solar homeowners.
How Do Batteries Help With Time-of-Use Rates?
A home battery can lower TOU costs by changing when your home draws power from the grid. Paired with solar, the battery stores excess daytime generation and discharges it during the pricier peak window. Some systems can also charge from the grid during cheap off-peak hours and discharge as rates rise, depending on your rate plan and equipment.
Whether this actually saves money comes down to the gap between your peak and off-peak prices, battery efficiency, cycling limits, and how much peak-hour usage you can realistically shift.
Ways Solar Homeowners Can Make TOU Rates Work Harder
Schedule EV charging for off-peak overnight hours. NREL research shows that delayed or managed charging can meaningfully lower costs.
Add a battery to store midday solar production for evening peak hours. Our guide to adding batteries to an existing solar system walks through what that upgrade involves.
Compare battery backup to a generator if you're weighing resilience options.
Check your solar payback period, since TOU savings can shorten it.
Review current solar panel incentives while comparing your options.
Use your monitoring app to track production against usage throughout the day.
If your solar system was designed before TOU pricing became common in your area, it might be worth a second look. GreenLancer can help you troubleshoot performance, check your battery settings, and find repair or optimization options that fit your rate plan. Complete the form below to get started.
FAQs About TOU on Your Electricity Bill
What does TOU mean on my electricity bill?
TOU stands for time-of-use. It's a billing structure where the price of electricity changes depending on when you use it, with higher rates during peak demand hours and lower rates during off-peak hours.
What is a time-of-use (TOU) rate?
A TOU rate is a specific pricing plan built around that structure. Instead of one flat price per kilowatt-hour, your utility charges different rates for different times of day, and sometimes different rates by season as well.
What's the difference between TOU rates and tiered rates?
Tiered rates charge based on how much electricity you use in a billing period, with the price increasing once you cross a usage threshold. TOU rates charge based on when you use electricity, regardless of your total monthly usage.
Is a time-of-use rate cheaper than a flat electricity rate?
A time-of-use rate can be cheaper than a flat rate if you can shift enough electricity use into lower-priced off-peak hours. It may cost more if you use a lot of electricity during expensive peak periods. Compare your actual hourly usage with your utility's TOU schedule before switching plans.
What electric companies offer TOU billing plans?
Many major U.S. utilities offer TOU billing, including PG&E, Southern California Edison, Con Edison, Duke Energy, SDG&E, and Georgia Power. Coverage and plan details vary widely, so check directly with your provider for your area's options.
Are weekends considered peak or off-peak TOU rates?
Sometimes, but not always. Some TOU plans treat weekends as off-peak, while others keep the same evening peak window every day of the week, including weekends. Check your specific utility rate schedule to confirm how your plan handles it.
Does TOU billing apply year-round?
TOU rates typically apply year-round, but the specific hours and prices often shift by season. Summer months usually carry higher peak pricing due to increased air conditioning demand.
Why are summer electricity bills so big under TOU billing?
Summer bills climb because air conditioning use spikes right during peak pricing hours. That combination of higher usage and higher per-kWh rates can add up quickly if habits don't shift toward off-peak times.
Will I save money on electricity bills with TOU rates?
It depends on your flexibility. If you can shift energy-heavy tasks like laundry, dishwashing, or EV charging to off-peak hours, a TOU plan can lower your bill. If most of your usage happens during peak hours and can't move, you may end up paying more.
Is there a calculator to estimate my own TOU savings?
Yes. This page includes a TOU savings calculator that compares your current flat-rate cost with an estimated TOU cost, based on the rates and usage you enter, and shows how much shifting electricity to off-peak hours could save.
Do electric vehicle owners benefit from TOU billing?
Often, yes. Charging an EV overnight during off-peak hours can meaningfully cut charging costs compared to charging during peak windows or on a flat rate plan.
Can solar panels help lower TOU peak-hour costs?
Solar can help, especially when paired with a battery. Panels alone may not cover peak-hour usage since production often drops before evening peak pricing begins, but stored solar energy can fill that gap.
How can I find my utility's peak and off-peak hours?
Check your bill, your online utility account, or your rate schedule. Search for your specific rate plan by name rather than relying on general estimates, since TOU windows vary by utility, season, and customer class.
Comments