Applies to solar interconnected after April 15, 2023

Charging your EV on solar surplus with SDG&E (NEM 3.0 / net billing)

Under NEM 3.0, San Diego Gas & Electric pays you 5.5¢ for each kWh of solar you export, and charges about 40¢ for each kWh you buy back. Putting that surplus into your car instead of the grid keeps the difference.

See your number How the math works
The spread

What SDG&E pays for solar vs. what it charges for power

Export credit
5.5¢/kWh
What an exported kWh earns
Blended import rate
40¢/kWh
What a kWh from the grid costs, averaged

A kWh you keep is worth 7× what it earns exported.

Tariff: NBT Solar Billing Plan (EV-TOU-5) · Rates as of July 2026. A reference figure, not a bill quote — your own rate depends on your plan, season and time of use.

Under the Solar Billing Plan, SDG&E credits exports at the CPUC's avoided-cost values, which change hour by hour — a small fraction of what you pay to import. EV-TOU-5's peak and super-off-peak prices sit far apart, so your blended import rate depends on when you use power.

Worked example

One July month: export it, or drive on it?

An 8 kW system with 20 kWh/day of July surplus, and an EV driven 40 miles a day at 3.5 mi/kWh (about 11.4 kWh/day). The car can absorb 11.4 of the 20 kWh, so 343 kWh a month goes to the car instead of the grid.

Where the 343 kWh goesRatePer month
Exported to SDG&E5.5¢/kWh credit$18.86
Charged into your EV (grid imports avoided)40¢/kWh avoided$137.14
Difference from charging on solar$118.29

Illustrative; the calculator uses your zip and plan.

Does this apply to me?

Three things to check

Interconnected before April 15, 2023? You're most likely on NEM 2.0 (typically a DR or TOU-DR plan), which credits exports near the retail rate for 20 years from your permission-to-operate date. The gap on this page mostly doesn't apply to you until that term ends — though SundialEV still keeps EV charging off peak-rate grid power.

Compatible gear

Works with the equipment SDG&E homes already have

Tesla Powerwall

Solar, grid and battery from your Powerwall, with a battery-priority setting.

How it works →

Enphase

Enphase production, plus grid and IQ Battery when your system meters them.

How it works →

Wallbox Pulsar Plus

Any EV, charged on surplus. SundialEV throttles the charger over OCPP.

How it works →

Your SDG&E number, from your zip

The calculator starts from SDG&E's rates for your zip and plan, then lets you adjust your system size and driving.

For solar interconnected after April 15, 2023 (NEM 3.0).

FAQ

Frequently asked questions

Does SundialEV work with SDG&E's EV-TOU-5?
Yes. SundialEV charges your EV from whatever solar your home would otherwise export, on any SDG&E plan. Your plan matters for the savings math: SundialEV values each kWh at your plan's rates (NBT Solar Billing Plan (EV-TOU-5) by default, and you can change it), and you can set avoid-hours so grid top-ups skip your peak window.
Do I need to install anything?
No. SundialEV connects through the cloud APIs of the gear you already own — your Tesla, your solar or battery system, or your wall charger. No extra meter, no new wall connector, no electrician.
How much will I save with SDG&E?
It depends on how much surplus you export and how much you drive. In the illustrative example on this page (20 kWh/day of July surplus, 40 miles a day), charging the car instead of exporting is worth about $118.29 a month at SDG&E's rates as of July 2026. The calculator runs the same math with your zip and plan.
Does this work without a Powerwall?
Yes. A Powerwall adds battery-priority options, but SundialEV works with solar and an EV alone: when there's surplus, it goes to the car.
Do I need a Tesla?
No. Tesla vehicles are controlled directly, and any other EV works through a supported wall charger — the Wallbox Pulsar Plus over OCPP, or an Emporia charger through Emporia's cloud — which SundialEV starts, stops and throttles to match your surplus.

Keep your SDG&E surplus in the car

SundialEV charges from your surplus automatically.

Get started on web Estimate your savings →