Southern California Edison EV rate analysis.

Why we focus on utility rate design

As we've discussed and demonstrated through multiple head-to-head case study comparisons on this site, the absence of the federal EV tax credit has made the economic argument for EVs more challenging. While the California CCVRP $2,000 rebate remains active, the recurring analytical finding throughout Drive Economics is that utility electric vehicle rates or time-of-use rates are critical to a total cost of ownership edge for EVs. Get the rate wrong and the operational advantage that EVs are supposed to deliver can shrink to nothing — or worse.

Given SCE's relatively higher $ per kWh than most of the country, it's especially important for Southern California EV drivers to be cognizant of their utility rate options and understand the pros and cons of each. The rate choice matters more in California than almost anywhere else in the country because California electricity is expensive by any comparison. Small percentage differences translate to real dollars quickly.

SCE electric rate options at a glance

SCE offers several residential rate schedules. Three matter for most EV owners. Summer rates shown; winter rates are modestly lower.

Path 1: TOU-D-4-9PM — the default TOU with no fixed EV charge

TOU-D-4-9PM is SCE's default residential TOU rate. The structure is straightforward: off-peak hours are cheaper, peak hours (4-9 PM weekdays) are dramatically more expensive. Summer off-peak rate for a disciplined EV charger locking to overnight or weekend hours is approximately $0.34/kWh all-in (supply plus delivery combined). No fixed monthly EV surcharge beyond the customary basic customer charge that all SCE residential customers pay.

For an EV owner charging 4,500 kWh/year (15,000 mi/yr at 30 kWh/100mi), TOU-D-4-9PM produces approximately $1,530 in annual EV charging cost, or $7,650 over 5 years. This is the baseline against which TOU-D-PRIME is measured.

Path 2: TOU-D-PRIME — the marketed EV rate

TOU-D-PRIME is SCE's dedicated EV and electric appliance rate. SCE's marketing positions it as the natural choice for EV owners — lower off-peak per-kWh rates (approximately $0.26 vs $0.34 for TOU-D-4-9PM summer) and structural rewards for time-shifting large loads to overnight and midday hours. Enrollment is exclusive to homes with a qualifying device: an EV, home battery storage system, or heat pump.

An interesting wrinkle that drivers need to factor is the $24 monthly grid service charge — approximately $288 per year in fixed costs that customers on TOU-D-4-9PM never pay. Fortunately, the ~$0.09/kWh spread between the two rates' summer off-peak charges makes this fixed charge relatively easy to amortize for typical residential mileage, as shown in the graph below.

TOU-D-PRIME does deliver value for typical and high mileage EV owners: single-EV households at typical mileage, two-EV households, drivers with long commutes plus significant weekend driving, rideshare drivers, delivery drivers. For these buyers, the fixed charge is amortized across enough kWh that the per-kWh savings dominate. The plan is analytically sensible for a much broader audience than the fixed-charge structure might initially suggest.

The break-even math: at what mileage does TOU-D-PRIME pay back?

The chart below plots annual EV electricity cost across a range of annual mileage for both rate options. The lines cross at exactly the break-even mileage — above which TOU-D-PRIME saves money, below which it costs more. The finding, based on current SCE published rates, is that TOU-D-PRIME pays off for the majority of SCE EV owners.

The crossover happens at approximately 10,700 miles per year. Below that mileage, TOU-D-4-9PM is cheaper by up to $153 per year (at 5,000 mi/yr). Above 10,700 mi/yr, TOU-D-PRIME saves money — modestly at first ($117/year at 15,000 mi/yr, or $585 over 5 years), then more substantially at higher mileage. For a typical Southern California EV owner driving above 12,000 mi/yr, TOU-D-PRIME delivers real savings over the default rate — assuming they qualify for enrollment (EV, battery, or heat pump ownership required). It's worth noting that TOU-D-PRIME is particularly well-suited for heavy, flexible energy loads that can be shifted to off-peak hours — such as charging an EV overnight, running a home battery backup system, or operating a heat pump. This is something we'll explore in a future case study.

The savings scale meaningfully with mileage. At 20,000 mi/yr, TOU-D-PRIME saves approximately $252 per year, or $1,260 over 5 years. At 30,000 mi/yr, savings reach approximately $522 per year, or $2,610 over 5 years. For higher-mileage households, two-EV Southern California homes, or drivers with heat pump or home battery loads to shift, TOU-D-PRIME materially reduces electricity costs.

Rate option summary

At this point, we should clarify that this analysis has focused solely on the time-of-use rate options. We found the ~10,700 mile per year balance point an interesting find — well below typical annual mileage for Southern California residents. This means TOU-D-PRIME enrollment is the analytically correct choice for most SCE EV owners who qualify. Additional characteristics that impact the economics:

• Actual mileage across all household EVs. Under 10,000 mi/yr combined (rare for a Southern California household): stay on TOU-D-4-9PM. The default rate saves up to $153 per year at very low mileage. Between 10,000 and 12,000 mi/yr: TOU-D-PRIME edges out the default slightly — modest savings. Above 12,000 mi/yr (which describes most SCE EV households): TOU-D-PRIME saves meaningfully, with savings growing to $500+/year at higher mileage.
• Availability of Wi-Fi-enabled Level 2 smart charging with schedule enforcement. If yes: either rate works for capturing off-peak savings. If no: TOU-D-4-9PM is the only viable choice — without automation, you cannot reliably capture the off-peak rate on either plan, but TOU-D-4-9PM has no fixed penalty for imperfect discipline.
• Summer AC exposure during 4-9 PM weekday afternoons. Both rates have punishing peak rates during this window (~$0.55-$0.62/kWh in summer), so heavy peak-hour AC use is expensive on either plan. If your household unavoidably runs AC during 4-9 PM summer peak, model your realistic total electricity bill carefully — the $288/yr TOU-D-PRIME fixed charge stacks on top of high peak-hour costs.

The Southern California summer heat factor

SCE rate options have punishing peak rates during 4-9 PM weekday windows — approximately $0.58-$0.74/kWh in summer months, depending on the specific rate. In Southern California, this window falls squarely inside the daily air conditioning demand curve. Inland Empire summer afternoons routinely hit 100-110°F; LA basin summers regularly hit 90-95°F even without extreme heat events. Households cannot meaningfully avoid running AC during 4-9 PM in July, August, and September.

This creates a structural challenge that no rate plan can fully solve. Even a household with perfect EV charging discipline (100% off-peak) will accrue meaningful peak-hour costs from summer AC. For a typical Inland Empire home running 3-5 kWh per hour of AC during 4-9 PM peak (15-25 kWh per day), the summer peak-hour electricity cost is $9-15 per weekday, or $200-$350 per month during peak summer.

The practical implication for EV rate choice: the fixed peak-hour cost of running summer AC is much larger than the difference between TOU-D-4-9PM and TOU-D-PRIME. Neither rate plan makes summer AC affordable. What matters for the EV rate decision specifically is not summer peak exposure (both plans have it), but rather how the $288/yr TOU-D-PRIME fixed charge compounds on top of the already-high summer bills. For households already stretched by summer electricity costs, TOU-D-PRIME's fixed charge is real additional pain without commensurate benefit for typical EV mileage.

See it in our case studies

The LA Ioniq 5 vs Tucson Hybrid case shows the SCE rate choice in practice with a real buyer scenario. Elena is a Pasadena product designer driving approximately 12,000 miles per year with a mix of Metro rail commuting and short-radius errands.

How this compares to peer utility EV plans

SCE's TOU-D-PRIME sits alongside SDG&E EV-TOU-5 as the two US utility EV rates with substantial fixed monthly charges. The comparison across peer utilities highlights how unusual the SCE structure is:

Rates are approximate and reflect published tariffs as of publication.

Three observations. First, SCE TOU-D-PRIME's $24 fixed charge is the highest EV-rate fixed charge in the library — 50% higher than SDG&E's $16 EV-TOU-5 charge and totally absent on midwest utilities and PG&E EV-2A. But with SCE's substantial ~$0.09/kWh off-peak rate spread, that fixed charge is easily amortized for typical mileage. Second, PG&E in northern California has a similar high-cost rate landscape but without SCE's exclusivity requirement (TOU-D-PRIME requires EV, battery, or heat pump ownership), making PG&E EV-2A the more universally-accessible California rate structure. Third, the SCE default TOU-D-4-9PM rate is competitive with peer utilities on both rate and lack of fixed charge — it is a perfectly good rate for typical EV owners without requiring the TOU-D-PRIME upgrade.

Rate figures reflect SCE published tariffs as of September 2026 and are approximate. TOU-D-4-9PM summer off-peak of ~$0.34/kWh represents effective rate for disciplined off-peak charging (winter off-peak drops to ~$0.33-$0.37/kWh depending on tier). TOU-D-PRIME summer off-peak of ~$0.26/kWh and winter super off-peak of ~$0.24/kWh are averaged in the chart at a blended ~$0.25/kWh. Actual seasonal split varies by household usage pattern. Grid service charge of ~$24/month reflects TOU-D-PRIME basic service charge and is subject to change. Peak rates of ~$0.58/kWh (TOU-D-4-9PM), ~$0.74/kWh (TOU-D-5-8PM), and ~$0.59/kWh (TOU-D-PRIME) reflect summer weekday exposure and vary by season, tier, and specific tariff schedule. Baseline credits reduce first-tier usage rates by approximately $0.10/kWh. Break-even mileage of ~10,700 mi/yr assumes 30 kWh/100mi EV efficiency and blended summer/winter rates; actual break-even varies with vehicle efficiency, seasonal usage patterns, and specific rate tier. Actual rates vary based on SCE's current published tariff, CPUC-approved adjustments, and individual customer usage patterns. Verify current rates at sce.com before making enrollment decisions. CCVRP rebate amounts are administered by the California Air Resources Board and vary by household income tier; verify current program terms at cleanvehiclerebate.org. Peer utility rates in the comparison table are similarly approximate and reflect the utilities' published EV rate tariffs; see individual utility program pages for detail on each.