By EV Charge Cost Editorial Team. Published September 28, 2026, updated October 26, 2026.
Solar panels and EVs are a natural pair: one makes electricity at home, the other uses a lot of it. But the savings are easy to overstate. The key is to value solar power correctly, and that depends on your electricity rate and on how your utility treats power you send to the grid.
How to value solar power for charging
Once a solar system is installed, its output has no fuel cost. What it saves is the electricity you would otherwise have bought. So the value of a solar kWh used to charge your car is roughly your retail price per kWh, including delivery charges that scale with usage.
If you are on net metering, where exported power is credited at or near the retail rate, it makes little difference whether the car charges while the sun shines or at night. If your utility credits exports at a lower rate, solar power used directly is worth more than solar power exported, and daytime charging becomes more valuable. Net metering and export rules vary by utility and state and change over time, so check your own.
How much of a solar system an EV uses
A 33.5 kWh/100 mi EV driven 13,500 miles a year uses about 4,523 kWh, or around 12.4 kWh a day. To make that concrete, take an illustrative home system producing 6,000 kWh a year. Real output depends on system size, location, roof orientation, shading and weather.
- The EV would use about 75% of that illustrative system's yearly output.
- On an average day the system would make about 16.4 kWh, against the EV's 12.4 kWh.
- Output is much higher in summer than in winter, while EVs use more energy in winter, so monthly coverage varies.
What it is worth by state
The value of powering the EV from solar is simply what that electricity would cost from the grid. It is highest where grid power is expensive.
| Where | Grid price | Value per year | Value per month |
|---|---|---|---|
| Nevada (cheapest) | 12.72¢/kWh | $575 | $47.94 |
| Alabama (near median) | 16.33¢/kWh | $739 | $61.54 |
| Hawaii (most expensive) | 47.18¢/kWh | $2,134 | $177.81 |
| U.S. average | 18.16¢/kWh | $821 | $68.44 |
These are values of the electricity, not net savings on a solar purchase. Whether a solar system pays off also depends on its cost, financing, incentives and lifespan, which this site does not track.
When exports earn less than retail
If your utility credits exported solar at less than the retail rate, the power you export and later buy back at night is worth less. The table shows, for illustration only, what 4,523 kWh of charging would be worth at the U.S. average under different assumed export credits, if all charging happened at night from exported-and-reimported power.
| Assumed export credit | Credit per kWh | Value per year | Lost vs direct use |
|---|---|---|---|
| 100% of retail | 18.16¢/kWh | $821 | $0 |
| 75% of retail | 13.62¢/kWh | $616 | $205 |
| 50% of retail | 9.08¢/kWh | $411 | $411 |
In that situation, shifting charging to sunny hours captures the full retail value. Cars that sit at home during the day, or a charger that follows solar output, help.
Practical tips
- Know your export rule before choosing when to charge.
- Charge at midday on weekends and days at home if exports earn less than retail.
- Check time-of-use windows. In some places off-peak hours now include midday; see the cheapest time to charge.
- Use your real rate. Enter it in the charging cost calculator to see the grid cost solar replaces, and compare states on the rankings page.