An electric vehicle is usually the largest single load a household adds. A driver covering 12,000 miles a year adds roughly 3,500 to 4,000 kWh of annual consumption, which for many Southern California homes is a 30 to 50 percent increase over previous usage.
That has two consequences. Charging at home costs more here than most national guidance suggests, and a solar system sized before the vehicle arrived will not cover it. Both are solvable, but only if the vehicle is part of the design conversation.
National articles commonly quote around 12 cents per kWh. That figure has nothing to do with this region and using it will lead you to the wrong conclusion.
On SCE, the average residential rate sits near 35 cents per kWh in 2026. Summer peak pricing between 4 p.m. and 9 p.m. reaches roughly 58 cents on the standard TOU-D-4-9PM plan and higher on some others. Off peak rates run considerably lower.
On LADWP, tiered residential rates are generally lower than SCE, and solar offsets your highest tier first.
Put numbers to it. A vehicle consuming roughly 0.3 kWh per mile and driven 12,000 miles a year uses about 3,600 kWh. Charged entirely during the SCE evening peak, that is a materially different annual cost than charging the same vehicle off peak, and different again when solar covers part of it. The timing of your charging matters as much as the fact of it.
This is why an EV changes the conversation rather than simply adding to it.
The cheapest kWh is the one you avoid buying at peak.
Avoid the 4 p.m. to 9 p.m. window. This is when rates are highest and when household demand is already elevated. Plugging in on arrival home is the default behaviour and it is the most expensive option available.
Use scheduled charging. Nearly every EV and every Level 2 charger supports a schedule. Setting charging to begin after the peak window ends is the single highest value change most EV owners can make, and it costs nothing.
Consider your rate plan. SCE’s TOU-D-PRIME is designed for households with an EV, solar, storage or a heat pump and carries a lower off peak rate alongside a higher peak rate. New solar customers are commonly placed on it. Whether it suits you depends on how much load you can move out of the peak window.
From solar directly: yes, when practical. If someone is home during the day or the vehicle sits in the driveway on weekends, charging during production hours converts power that would otherwise export at a low credit into transportation at full retail value. Under net billing that is the most efficient use of your own production.
From your battery: usually not the priority. A home battery holds 10 to 15 kWh per unit. A vehicle charging session can consume a large share of that, which leaves less available for evening household loads and backup reserve. Batteries generally deliver more value covering the home through the peak window than topping up a car.
The better arrangement for most households is solar sized to cover the vehicle across the year, daytime charging where the schedule allows, off peak charging otherwise, and the battery reserved for household peak shaving and outage protection.
There are exceptions. Discuss it during design rather than assuming either way.
A Level 2 charger runs on a 240 volt circuit and charges far faster than a standard household outlet. The installation is more than mounting a unit on a wall.
Your existing service has a finite capacity. Before adding a 240 volt circuit, the total connected load has to be assessed against that capacity. This is a code requirement, not a formality.
Many older Southern California homes have 100 amp service or a full panel with no available spaces. An EV charger, a heat pump and a battery all compete for the same capacity.
If capacity is short, the options are a service upgrade, a subpanel, or a load management device that prevents the charger and other large loads from running simultaneously. Load management is often the less disruptive and less expensive route, and it is frequently not offered by installers who do not do electrical work.
Sized for continuous load with the correct breaker and wire gauge for the distance involved.
Required by your local authority having jurisdiction.
Where the vehicle parks, where the panel sits, and the run between them drive the cost more than the charger itself does.
Two homes with identical current bills can need very different systems if one is adding a vehicle.
Tell your installer about a vehicle you plan to buy, not only one you already own. Adding 3,500 to 4,000 kWh of annual load to a system designed without it produces exactly the disappointing outcome we get called about later.
The design should account for annual vehicle mileage, how much charging can realistically happen during daylight, your rate plan, and whether a second vehicle is likely. Under net billing, the goal is a system where the production you generate lines up with load you actually have, and an EV is a genuinely useful load because it is flexible. You can move it in time in a way you cannot move an air conditioner.
If solar, storage and EV charging are all on your list within the next few years, plan them as one project even if you install them in stages. Doing so means one load calculation, one decision about service capacity, conduit run once, and a battery sized with the vehicle in the picture.
Homeowners who add these piecemeal frequently pay for the same electrical work twice.
It depends on your utility, rate plan and charging time. SCE residential rates average near 35 cents per kWh with summer peak reaching roughly 58 cents, so charging off peak rather than during the 4 p.m. to 9 p.m. window makes a substantial difference.
Yes, most vehicles include a cord for a standard 120 volt outlet, but charging is slow and generally impractical as a primary method for daily driving.
Sometimes. It depends on your existing service capacity and current loads. A load calculation determines this. Load management can sometimes avoid an upgrade.
Usually not as a primary strategy. Household battery capacity is generally more valuable covering evening peak loads and backup than charging a vehicle.
Roughly 3,500 to 4,000 kWh of additional annual production for 12,000 miles of driving, adjusted for your vehicle's efficiency and how much you can charge during daylight.
TOU-D-PRIME is designed for homes with EVs, solar, storage or heat pumps. Whether it is best for you depends on how much load you can shift out of the peak window.
Yes. We install Level 2 chargers and the supporting electrical work as standalone projects.
Green Additions designs and installs custom solar, battery storage, EV charging, and electrical solutions for Southern California homeowners.
Licensed California Solar Contractor
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