SCE Time-of-Use Rates Explained: How Solar Homeowners in Temecula Pay Less by Timing Their Consumption

Adrian Marin|Independent Solar Advisor, Temecula CA

Helping Riverside County homeowners navigate SCE rates and solar options since 2020

Every new solar customer in SCE territory is on a time-of-use rate schedule. That means the same kilowatt-hour costs 14 cents at 1am and 34.5 cents at 6pm. If you understand when rates are cheap and expensive, and align your consumption and storage accordingly, your solar investment performs significantly better. Here is how it works in plain terms.

What Time-of-Use Rates Mean and Why SCE Uses Them

A flat electricity rate charges the same price regardless of what time of day you use power. Time-of-use (TOU) rates charge different prices based on when you consume electricity. SCE moved all solar customers to TOU pricing because the timing of solar production and grid demand are fundamentally misaligned, and pricing that reflects real-time grid conditions encourages customers to shift consumption to periods when power is abundant.

Solar panels in Southern California produce peak power from roughly 10am to 2pm. Grid electricity demand peaks from 4pm to 9pm, when air conditioners are still running hard after a hot afternoon and households return home to cook, watch television, and run appliances. During the solar peak, the grid has an abundance of cheap solar power. During the late afternoon and evening peak, solar is declining and the grid must rely on natural gas peaker plants that are expensive to run and have high carbon emissions.

TOU pricing translates that reality into your electricity bill. Using power when it is abundant costs little. Using power when it is scarce costs more. For a solar homeowner who understands this, TOU rates are an opportunity to strategically reduce bills far below what a flat-rate customer can achieve.

SCE TOU-D-PRIME: The Rate Schedule That Applies to You

All new solar customers who interconnected under NEM 3.0 (after April 14, 2023) are placed on TOU-D-PRIME by default. Many existing NEM 2.0 solar customers have also migrated to TOU-D-PRIME. This is the rate schedule you need to understand.

TOU-D-PRIME divides each day into three pricing windows:

Super Off-Peak: Your Cheapest Hours

Super off-peak applies from midnight to 6am and from 10am to 2pm on weekdays. On weekends during winter months, additional hours may qualify as super off-peak depending on the rate schedule year. The approximate rate is 14-17 cents per kWh.

The midnight to 6am window is cheap because demand is at its daily minimum. Nearly all air conditioners are off, industrial loads have stopped, and the grid has surplus power. For an EV owner or anyone running a dishwasher on a delay timer, this is the window to target.

The 10am to 2pm window is cheap because solar production across California is at its daily maximum, flooding the grid with low-cost electricity. For solar homeowners, this window is when your panels are producing most of their daily output. Any home consumption during these hours draws on your own solar at effectively zero grid cost. Any excess production can charge a battery at the super off-peak rate for later use.

Off-Peak: The Transition Periods

Off-peak hours on weekdays are roughly 6am to 10am, 2pm to 4pm, and 9pm to midnight. The approximate rate is 28-31 cents per kWh, about double the super off-peak rate.

The morning off-peak window (6am to 10am) is when solar production is ramping up but has not yet reached its peak. Many households have high morning consumption (coffee makers, showers, blow dryers, morning TV). A solar homeowner in this window benefits from rising production offsetting morning loads, but may still import some grid power at the off-peak rate before solar fully covers the home.

The afternoon off-peak window (2pm to 4pm) is a transition period: solar production is declining from its noon peak but still strong, and on-peak pricing has not yet started. The 9pm to midnight window is post-peak: air conditioner loads are dropping, the household is winding down, and grid stress is easing.

On-Peak: The Hours to Avoid

On-peak applies from 4pm to 9pm every day of the year on TOU-D-PRIME. The rate is approximately 34.5 cents per kWh. In summer months (June through September), additional demand charges may apply on top of the energy rate for high-usage customers.

34.5 cents is more than twice the super off-peak rate. For a home drawing 3 kW during the 4pm to 9pm window (a moderate air conditioner plus normal appliances), that is $5.18 in on-peak charges for those five hours alone. Repeated every day of summer, that is $155 per month from just the 4-9pm window.

For a solar homeowner without battery storage, the 4-9pm window is the most expensive period of the day, and it is precisely the window when solar production is declining. A system producing 10 kW at noon may produce only 2-4 kW at 4pm and nothing by 6:30pm. The home imports increasing amounts of expensive grid power through the entire on-peak period.

How to Read Your SCE Bill to Find TOU Charges

Your SCE bill itemizes consumption by TOU tier. Here is what to look for:

On the "Electric Charges" section of your bill, you will see line items separated by tier: "On-Peak kWh," "Off-Peak kWh," and "Super Off-Peak kWh" with the consumption in kilowatt-hours and the rate applied to each. The "NEM Credit" line shows what SCE credited for your solar exports during each tier, with NEM 3.0 export credits appearing as a separate credit at the Avoided Cost Calculator rate (typically 5-8 cents per kWh rather than the retail rate).

The most useful number to find is your on-peak consumption in kilowatt-hours per month. This tells you exactly how much expensive grid power you are importing during the 4pm to 9pm window. If that number is high, a battery system that covers your on-peak load with stored solar has a larger financial opportunity to capture.

SCE's online portal at sce.com shows your hourly consumption data for the past 24 months if your meter is a smart meter (which all new meters in SCE territory are). Downloading your hourly data and sorting by hour of day gives you a clear picture of when you consume power and how much of that falls in each TOU tier.

The Production-Demand Mismatch: Why Solar Peaks at Noon but Rates Peak at 4pm

This is the central challenge for solar homeowners under TOU pricing. Your panels are at maximum output from roughly 11am to 2pm. SCE charges the most from 4pm to 9pm. Those windows do not overlap. Every kilowatt-hour your solar system produces at noon has two possible fates:

• Consumed immediately by your home: this replaces a kilowatt-hour that would cost 14-17 cents (super off-peak) from the grid. Value: 14-17 cents.
• Exported to the grid: SCE credits you approximately 5-8 cents under NEM 3.0 Avoided Cost Calculator rates. Value: 5-8 cents.
• Stored in a battery: the battery discharges at 5pm, replacing a kilowatt-hour that would cost 34.5 cents from the grid. Value: 34.5 cents.

The battery path captures 2-6 times as much value as the export path for the same kilowatt-hour of solar production. This is the mathematical foundation of battery storage economics under NEM 3.0 and TOU-D-PRIME.

Without a battery, a solar system in Temecula under NEM 3.0 gets most of its value from avoiding daytime grid imports (which are already at the cheap super off-peak rate during the highest production hours) and earns poor export credits. With a battery, the system also eliminates on-peak imports at 34.5 cents, capturing the largest rate differential available.

Battery Arbitrage: Storing Noon Solar to Discharge at Peak

Battery arbitrage under TOU-D-PRIME has a clear daily cycle. From 10am to 4pm, your solar system produces more than your home consumes. That excess charges the battery rather than exporting to the grid. At 4pm, the on-peak period begins. The battery management system switches to discharge mode, drawing down stored energy to power the home instead of importing from the grid at 34.5 cents.

For a 3,000 square foot Temecula home with central air conditioning, a dishwasher, refrigerator, and typical appliance loads, on-peak consumption from 4pm to 9pm on a summer day is typically 8-12 kWh. A 13.5 kWh Tesla Powerwall 3 can cover that entire five-hour window from stored solar, with energy to spare for the post-peak wind-down.

The daily arbitrage value: 10 kWh at 34.5 cents avoided (plus the export credit you would have earned if you had exported instead of stored). The avoided grid purchase is $3.45. The foregone export credit at 6 cents is $0.60. Net daily arbitrage benefit: $2.85 per day, or roughly $1,040 per year. This calculation varies by home size, consumption patterns, and the season, but illustrates why battery storage paired with TOU-D-PRIME is a different economic decision than battery storage was under NEM 2.0's near-retail export credits.

Smart Thermostat Programming for TOU Rates

Air conditioning is typically the largest on-peak electricity consumer in a Temecula home. In July and August, afternoon temperatures reach 100-108 degrees, and an air conditioner running at full load during the 4pm to 9pm on-peak window can easily draw 4-6 kW continuously. At 34.5 cents, that is $1.38-2.07 per hour, or $6.90-10.35 for the full five-hour peak window.

A smart thermostat programmed for TOU rates uses the house itself as a thermal battery. The strategy is pre-cooling: set the thermostat to cool the home more aggressively during the 10am to 2pm super off-peak window (when your solar is producing at maximum and grid power is cheapest), then allow the home to drift warmer during the 4pm to 9pm on-peak window.

Concretely: cool to 73-74 degrees by 3:45pm, then set the thermostat to 78-80 degrees during the peak window. The thermal mass of a well-insulated Temecula home (concrete slab, stucco walls, ceiling insulation) holds coolness for 2-4 hours. If the home drifts from 74 to 78 degrees between 4pm and 7pm, the air conditioner runs little or not at all during the most expensive hours.

At 7-8pm, as outdoor temperatures begin dropping below 90 degrees, the air conditioner catches up more efficiently. By 9pm when off-peak rates resume, the home is comfortable and the overnight cooling load is modest.

Ecobee and Nest both offer TOU-aware scheduling. SCE's Rate Ready program can connect your thermostat directly to rate schedules so it optimizes automatically without manual programming. This integration allows the thermostat to pre-cool aggressively before a peak period even if your normal schedule would not call for it.

A well-executed pre-cooling strategy in a Temecula home can reduce on-peak HVAC consumption by 40-60%, translating to $40-80 per month in summer bill savings from thermostat programming alone.

EV Charging Timing Under TOU-D-PRIME

An electric vehicle adds a substantial new electricity load to a home. The timing of that charging has enormous cost implications under TOU rates. Here is the math for a typical EV with a 60-70 kWh battery pack:

Charging midnight to 6am (super off-peak): 60 kWh at 14-17 cents costs $8.40-10.20. This is the cheapest possible scenario: no solar needed, pure off-peak grid power. Most EV owners program their charger to a midnight start and wake up to a full battery.

Charging 10am to 2pm from solar (super off-peak + self-consumption): if you work from home or have a Level 2 charger, charging directly from solar production during peak sun hours means the EV is running on solar electrons at effectively zero grid cost. For a home with sufficient solar production, this is the optimal daytime strategy.

Charging 4pm to 9pm (on-peak): 60 kWh at 34.5 cents costs $20.70. This is the most expensive scenario and should be avoided entirely. An EV plugged in at 6pm on a default charging setting will often draw 7-11 kW for several hours, adding $7-11 in on-peak charges per session. If your household drives and charges daily, this mistake costs $150-200 per month in avoidable on-peak charges.

All major EV manufacturers (Tesla, Ford, GM, Rivian, Hyundai/Kia) allow scheduled charging in the vehicle's settings or companion app. Set the schedule to begin at midnight and end before 6am. If you have a home energy management system or smart charger (ChargePoint, JuiceBox, Emporia), connect it to your TOU schedule for automatic rate-aware charging.

How NEM 3.0 Export Values Align With TOU Rates

Under NEM 3.0, export credits are not calculated at the retail TOU rate you pay for imports. They are calculated at the Avoided Cost Calculator (ACC) rate, which reflects the marginal cost of the power the grid avoids generating when you export. The ACC rate varies by time of day and season.

The ACC rate peaks during on-peak hours (4pm to 9pm) when the grid is avoiding its most expensive peaker plant generation. During off-peak and super off-peak hours when the grid has surplus solar, the ACC rate is lowest. For 2026, typical ACC rates for SCE territory are approximately:

• On-peak exports (4pm to 9pm): 10-20 cents per kWh, depending on season
• Off-peak exports: 5-10 cents per kWh
• Super off-peak exports (noon): 3-6 cents per kWh

This structure creates an interesting incentive: if you are going to export solar, exporting during the 4pm to 9pm window earns 2-4 times the export credit as exporting at noon. A battery can be programmed to partially discharge at 4pm (raising its on-peak export when it is most valuable), charge again if needed after 9pm at the super off-peak rate, and optimize this cycle for maximum financial return.

However, the on-peak export credit of 10-20 cents is still substantially less than the on-peak import cost of 34.5 cents. Self-consumption of stored solar during the on-peak window is always more valuable than exporting that same solar. The battery's primary financial job is avoiding on-peak imports, not earning on-peak export credits.

A Concrete Monthly Example: 3,000 Square Foot Temecula Home

To illustrate how TOU optimization translates to real bill savings, consider a typical 3,000 square foot home in Temecula or Murrieta with the following profile:

• Annual consumption: 1,400 kWh per month average, peaking at 1,800-2,000 kWh in July-August
• 10 kW solar system, producing approximately 1,500-1,600 kWh per month in peak summer
• On TOU-D-PRIME with a 13.5 kWh Powerwall 3
• EV charged on midnight schedule
• Smart thermostat programmed to pre-cool before 4pm

Without TOU optimization (solar only, no battery, no behavioral changes):

Solar produces 50-55 kWh per day. On-peak consumption (4-9pm): 12 kWh imported from grid at 34.5 cents = $4.14. Off-peak and super off-peak imports for overnight and morning loads: 15 kWh at 22 cents average = $3.30. Daily grid cost: $7.44. Monthly: approximately $220-230. Annual: $2,640-2,760.

With TOU optimization (battery + thermostat pre-cooling + midnight EV charging):

Battery covers 10-12 kWh of on-peak load: $0 imported during 4-9pm window. Smart thermostat reduces on-peak HVAC runtime by 50%: half the remaining on-peak load is covered by stored solar. EV charges at midnight at 14-17 cents instead of on-peak. Daily grid cost: $2.80-3.50. Monthly: approximately $85-105. Annual: $1,020-1,260.

Annual savings from TOU optimization: $1,380-1,740 per year on the electricity bill, in addition to the direct bill offset from solar production. Over 25 years at conservative assumptions, TOU optimization adds $20,000-30,000 in cumulative savings relative to having solar without optimizing when and how you use power.

The Other Appliances Worth Scheduling on TOU

Beyond HVAC and EV charging, several common appliances add meaningful on-peak load that can be shifted with simple timer programming:

• Dishwasher: a dishwasher draws 1.2-1.8 kW for 60-90 minutes. Running it at 10pm (off-peak) instead of 6pm (on-peak) saves 18-27 cents per run. At five runs per week, that is $47-70 per year from one schedule change.
• Clothes dryer: a heat pump dryer draws 1.5-2 kW. An electric resistance dryer draws 4.5-5.5 kW. Running it before 4pm or after 9pm saves $0.15-0.55 per load. A family running six loads per week saves $47-171 per year.
• Pool pump: a variable-speed pool pump running 8 hours per day is a significant load. Programming it to run 10am to 2pm (super off-peak) and midnight to 6am (super off-peak) instead of the default afternoon hours saves $15-40 per month on a pool home in Temecula.
• Water heater timer: if you have a standard electric water heater, adding a simple outlet timer or a smart water heater controller prevents it from drawing 4-5 kW during on-peak hours. Most daily hot water heating can be completed by 3:30pm and the tank will hold temperature until morning.

Frequently Asked Questions

What is SCE TOU-D-PRIME and why are solar customers required to use it?

TOU-D-PRIME is SCE's mandatory rate schedule for all new solar customers under NEM 3.0. It charges different prices by time of day: 14-17 cents per kWh super off-peak (midnight to 6am and 10am to 2pm), 28-31 cents off-peak, and 34.5 cents on-peak (4pm to 9pm). SCE moved solar customers to TOU because solar production peaks at noon while grid demand peaks at 4-9pm. TOU pricing reflects that mismatch and incentivizes customers to shift loads to cheaper hours.

What are the exact TOU-D-PRIME time windows and rates?

On weekdays: super off-peak from midnight to 6am and 10am to 2pm (14-17 cents), off-peak from 6am to 10am, 2pm to 4pm, and 9pm to midnight (28-31 cents), on-peak from 4pm to 9pm (34.5 cents). Summer months may include additional demand charges. Rates adjust periodically; check your bill or SCE's current rate schedule for exact figures.

Why does solar production peak at noon but SCE charge the most at 4-9pm?

Solar panels produce peak power when the sun is highest, around 11am to 2pm. Grid peak demand occurs in late afternoon and evening when solar is declining but air conditioners, cooking, and home electronics all run simultaneously. The 4-9pm on-peak window is when the grid has the least solar supply and the most demand. Battery storage captures noon solar and releases it at 4pm, bridging that gap.

How does battery storage use TOU rate arbitrage in Temecula?

Solar charges the battery during the 10am to 4pm super off-peak window. At 4pm, the battery discharges to cover the home instead of importing from the grid at 34.5 cents. The rate difference between storage cost (6 cents foregone export) and avoided import (34.5 cents) is roughly 28 cents per kWh. A 13.5 kWh Powerwall cycling this arbitrage daily captures $840-985 per year in avoided on-peak charges.

What is the cheapest time to charge an EV on SCE in Temecula?

Midnight to 6am is the cheapest window at 14-17 cents per kWh. A 60 kWh charge costs $8.40-10.20. Charging at 6pm during on-peak costs $20.70 for the same charge. Set your EV charger to a midnight schedule and save $10-15 per full charge cycle. During the day, 10am to 2pm solar production can charge the EV at effectively zero grid cost for homes with sufficient solar capacity.