If you already have solar panels and your utility charges time-of-use rates, you have a powerful opportunity to cut your electricity bill—but only if you understand the timing. Most solar owners on TOU rates see their panels produce the most power during midday off-peak hours, while their household uses the most electricity during expensive evening peaks. The gap between those two windows is where strategy matters.
What happens when your production doesn’t match demand
Time-of-use (TOU) rates mean electricity costs more at certain hours of the day, and the peak hours cost far more than the rest. Peak pricing usually lands on weekday late afternoons and evenings, often somewhere in the 4 to 9 PM window, when people get home and turn on lights, AC, appliances and the stove. Off-peak hours, such as late night and early morning, are cheaper because demand on the grid is low.
The problem for solar owners is straightforward: your panels produce the most energy during midday when electricity is cheap, but your household uses the most power during evening hours when electricity is expensive. Without a strategy to bridge that gap, you will export cheap power to the grid during the day and buy expensive power back at night.
In 2026, peak prices range from roughly 24 to 74 cents per kWh depending on the utility. PG&E in California has some of the widest spreads for solar and EV owners, with peak prices up to about $0.55 per kWh and off-peak as low as about $0.18. The wider the spread between peak and off-peak pricing, the more valuable your optimization strategy becomes.
Why battery storage changes the equation for TOU rate optimization
Getting the most from TOU rates comes down to using energy at a different time than you produce it, and that’s what a battery does. Your panels peak around midday, while TOU prices peak later. Without storage, you sell surplus solar at low daytime rates and then buy power back at high evening rates.
In arbitrage mode, the battery charges when electricity is cheap and discharges when it’s expensive. With a battery, you can save daytime solar for the 4 to 9 PM peak, when grid power can run $0.31 per kWh or more. Each stored kWh you use then is a kWh you don’t buy at the top rate.
In high-rate states such as California, New York and Massachusetts, solar plus a battery can save roughly $600 to $1,500 a year on TOU rates. That is not a projection—those are real-world outcomes from homeowners who have configured their systems correctly. If you are considering adding a battery to your existing solar system, understanding your utility’s TOU rate structure should be the first step. Learn more about choosing the right battery for your home.
A battery also keeps essentials running when the grid goes down. See does solar work during a power outage.
How to configure your battery for maximum TOU savings
Most home batteries sold today—Tesla Powerwall, Enphase IQ Battery, Franklin WH, and others—include a TOU arbitrage mode or similar setting in their control software. The names vary by manufacturer, but the function is the same: the battery charges during low-rate hours and discharges during high-rate hours based on the schedule you program.
Of SCE’s plans, TOU-D-PRIME has the biggest gap between peak and off-peak prices, which makes each stored kWh more valuable in the evening. Let the panels fill the battery during cheap daytime hours, then run the house from the battery from 4 to 9 PM. Set your battery to prioritize self-consumption during peak hours first, then allow export only if the battery is full and your household loads are covered.
Automation takes the guesswork out. Most battery apps can charge and discharge on your TOU schedule without you touching anything. If your system allows it, configure seasonal adjustments so the battery adapts to summer and winter peak windows. Most utilities shift their TOU schedules by season, and your battery should follow.
Check your inverter or battery app settings monthly. Utility rate schedules can change, and if your system is not updated to reflect the new peak hours, you may be discharging during cheap periods and drawing from the grid during expensive ones.
Load shifting strategies that work without a battery
If you have solar panels but no battery, you can still optimize around TOU rates by shifting when you use power-hungry appliances. Running big appliances and charging EVs outside peak hours is one of the simplest ways to save on TOU. The goal is to use as much of your solar production in real time as possible, then move discretionary loads to the cheapest rate windows.
On a TOU plan, run laundry and the dishwasher and charge the EV outside peak hours. Run your dishwasher, washing machine, and dryer during midday when your panels are producing. If you have an electric vehicle, set the charge timer to start after 9 PM or whenever your utility’s off-peak window begins. If you have a pool pump, program it to run between 10 AM and 2 PM when solar production is high and grid rates are low.
You can also pre-cool the house before peak hours start, so the AC runs less during them. Set your thermostat a few degrees cooler in the late afternoon while your solar is still producing, then let the house coast through the evening peak without heavy AC use. Small adjustments like these can shave 10–20% off your peak-hour consumption without requiring new equipment.
For more guidance on reducing costs and maximizing your system, visit our installer directory to connect with local solar professionals who specialize in TOU rate optimization.
Choosing the right TOU rate plan for your solar system
Not all TOU rate plans are created equal, and the best plan for a solar-only homeowner is often different from the best plan for someone with solar plus storage. Utilities like SCE offer several TOU plans for solar customers, and the three that matter most in 2026 are TOU-D-PRIME, TOU-D-4-9PM and TOU-D-5-8PM.
TOU-D-PRIME is only open to homes with electrification upgrades like an EV, solar, a battery or a heat pump. It charges a fixed 79 cents a day (about $24 a month) in exchange for lower per-kWh prices. Homes with a battery such as a Franklin WH or Enphase IQ Battery usually do best on this plan. The wider spread between peak and off-peak makes battery arbitrage more profitable.
If you have solar but no battery, TOU-D-4-9PM is usually the better fit, since you’ll be buying some power during the 4 to 9 PM peak no matter what. The goal on a solar-only plan is to minimize peak exposure, not eliminate it, because elimination is not possible without storage.
Most utilities allow you to switch rate plans once per year without penalty. If you are unsure which plan is best, request a bill analysis from your utility showing what your last 12 months of usage would cost under each available TOU rate. Many utilities provide this for free. If your usage patterns have changed—you added an EV, you installed a battery, or your household size shifted—it is worth revisiting your rate plan annually.
Your bill shows which rate plan you’re on and how exports are credited. See how to read your solar bill.
How reduced export credits change the math
Under California’s NEM 3.0 and similar policies elsewhere, midday exports earn far less than evening exports, often around 5 to 10 cents per kWh at midday versus 30 to 40 cents in the evening. That gap is the value a battery can capture. Check your bill or net metering statement to see what you’re actually credited for exports. If you installed before your state’s rules changed, you may still be grandfathered. Our guide to net metering changes explains how to check your status and what to do if your credits are cut.
Smart home devices and automation tools for TOU optimization
TOU billing needs a smart meter that records hourly use, and most utilities install one free when you switch. Smart thermostats, water heater controllers and EV charging timers make shifting easier, but plenty of people do fine with basic appliance timers.
Smart thermostats like Nest, Ecobee, or Honeywell Home can be programmed with TOU-aware schedules. Set them to precool or preheat your home during off-peak hours, then reduce heating or cooling output during peak windows. Most models let you configure multiple daily schedules, so weekdays and weekends can follow different patterns.
Smart plugs are inexpensive and effective for controlling devices that do not have built-in timers. Plug your pool pump, dehumidifier, or space heater into a smart plug, then schedule it to run only during your solar production window or off-peak hours. Many smart plugs integrate with home assistants like Alexa or Google Home, so you can create routines that trigger based on time of day or even real-time solar production data if your inverter supports integration.
If you have an electric vehicle, every major EV manufacturer includes charge scheduling in their app or vehicle settings. Program your car to begin charging at 9 PM or midnight, depending on when your off-peak window starts. Some utilities offer special EV rates with even lower overnight pricing—check if your utility has an EV-specific TOU plan before locking into a general residential rate.
Common mistakes solar owners make with TOU rates
The most common mistake is assuming your solar system will automatically optimize for TOU rates. It will not. Solar panels produce power whenever the sun is shining, regardless of what your utility is charging. If you do not actively manage when that power is used or stored, you will waste the price difference.
Another frequent error: undersizing your battery relative to your peak-hour consumption. A battery that’s too small leaves savings behind, and one that’s too big takes longer to pay off. If your household uses 15 kWh between 4 PM and 9 PM but your battery only holds 10 kWh, you are still buying 5 kWh from the grid at peak rates every day. Run the numbers before you buy. Most installers can provide a load profile analysis that shows your actual peak consumption and recommends appropriate battery capacity.
Some homeowners also fail to update their battery or inverter settings when their utility changes rate schedules. SCE’s summer season runs June 1 through September 30, 2026. That’s when TOU-D-4-9PM peaks at 58.3 cents per kWh and peak-hour use costs you the most. If your system is still configured for winter hours in July, you are losing money every single day.
Finally, do not ignore your utility’s export compensation rules. Some TOU plans limit or penalize grid charging—meaning you cannot charge your battery from the grid during cheap hours and discharge during expensive hours unless you have solar. Know the rules before you configure your system, or you could face unexpected charges.
Frequently Asked Questions
Final Thoughts
Time of use rates can either amplify your solar savings or quietly erode them, depending on how well you understand and respond to the timing mismatch between solar production and household demand. The utilities that have implemented TOU rates are not doing it to make your life harder—they are doing it to reflect the real cost of electricity at different times of day and to manage grid stress during peak periods. But that does not mean you have to accept higher bills.
If you already have solar and you are on a TOU rate, the single highest-value upgrade you can make is adding battery storage. If a battery is not in the budget right now, focus on load shifting: move your biggest energy users to midday or late-night hours, automate what you can, and monitor your usage patterns so you know where the waste is happening. Small changes compound over time, and even without a battery, disciplined load management can cut your peak-hour consumption by 20% or more.
EnergyScout exists to help you make informed decisions about your solar system without the sales pressure or jargon. If you are not sure whether your current setup is optimized for your utility’s rate structure, or if you are considering adding a battery and want to talk to someone who knows your local market, use our installer directory to find qualified professionals in your area. Your system is already installed—now make it work as hard as it should.