Home › Tools › Solar + EV charging calculator
How many solar panels does your EV need?
Pick a city and a car. We simulate every hour of a typical year, match your roof's output to when you actually plug in, and apply your state's rule for solar you send back to the grid.
Loading the solar model…
Panels—
Upfront cost—
Saved in year one—
Pays for itself—
EV charging per year—
Solar made per year—
Went straight into the car—
Sent to the grid—
Solar cost per kWh—
Month by month
Charged the car directly
Sent to the grid
Car's charging need
What changes the answer most
Years to pay back for your setup, by charging habit and by how your utility credits exported solar. Your current choice is outlined.
How each state credits solar you send to the grid
This is the rule the calculator starts with for each city: the main utility's tariff for new home solar customers, checked 2026-09-30. Rules change, and co-ops and city utilities often follow different ones, so the calculator also lets you pick a share of retail or type in your own export rate.
| State | Utility | Export credit | What it means |
|---|---|---|---|
| Arizona | APS | 5.55¢ per kWh | APS pays 5.55¢ per kWh for exported solar from 1 September 2026, locked for 10 years from when you connect. The Arizona Corporation Commission has cut the rate for new customers by 10% a year since 2018. Salt River Project (SRP) customers are on a different, lower export rate. PV Tech: ACC cuts Arizona solar export rate to 5.5 cents |
| California | PG&E | about 4.7¢ per kWh | Under California's Net Billing Tariff (often called NEM 3.0), exports earn hourly avoided-cost rates instead of the retail price. The California Solar & Storage Association puts the average at about 4.7¢ per kWh. Homes connected before April 2023 keep the older net metering rules. SolarReviews: NEM 3.0 in California |
| Colorado | Xcel Energy | full retail | Xcel Energy credits exported solar at the full retail rate and carries extra credit forward month to month. Credit still left at the end of the year is paid out at a lower rate. Apollo Energy: How Colorado net metering works in 2026 |
| Florida | FPL | full retail | FPL credits exported solar one-for-one at the retail rate and carries extra credit forward within the calendar year, under Florida PSC rule 25-6.065. Solar Learning Lab: FPL rates and solar rules in 2026 |
| Illinois | ComEd | about 10.1¢ per kWh, supply only | Since 1 January 2025, new ComEd solar customers get credit for exports against the supply part of the bill only, not delivery charges. ComEd's supply price is 10.103¢ per kWh from October 2026 to May 2027 and changes with the season. Illinois also pays a one-time rebate of about $300 per kW for systems with a smart inverter, which this calculator does not include. Citizens Utility Board: ComEd fall power price, SolarInsure: Net metering 2.0 in Illinois |
| Iowa | MidAmerican Energy | full retail | MidAmerican uses inflow-outflow billing: exported energy is credited at the retail volumetric rate, riders included. Iowa law lets utilities ask for a separate value-of-solar rate after 1 July 2027. Iowa Code 476.49, Iowa Utilities Commission: On-site generation |
| Nevada | NV Energy | 75% of retail | NV Energy credits exported solar at 75% of the retail rate for new customers, locked for 20 years at the address where the system was installed. Public Utilities Commission of Nevada: Net Metering |
| New Jersey | PSE&G | full retail | PSE&G credits exported solar one-for-one at the retail rate. Any surplus left at the annual true-up is paid at a wholesale rate. New Jersey's regulator is studying a successor program. NuWatt: New Jersey net metering guide 2026 |
| New York | Con Edison | full retail | Con Edison credits exported solar at the retail rate under net metering, with extra credit rolling forward month to month. Newer systems also pay a small monthly charge based on system size (the Customer Benefit Contribution), which this calculator does not include. Solarfy: Con Edison net metering in Queens |
| Oklahoma | OG&E | full retail | Oklahoma utilities net your solar against what you use in each billing period at the full retail energy rate. Only production above that month's use is paid at the utility's lower avoided cost. Oklahoma Corporation Commission: Net Metering |
| Virginia | Dominion Energy | full retail | Dominion nets exports against your use over 12 months at the full retail rate. The State Corporation Commission kept this in its NEM 2.0 order of 30 April 2026 and added a $1 monthly fee. Only a surplus left after 12 months is paid at the lower avoided cost. pv magazine: Virginia approves Dominion NEM 2.0 |
How this is calculated
- Solar output. Hour-by-hour simulation using the PVWatts v8 method on a typical weather year for each city: 20° roof, 14% system losses, 1.2 DC-to-AC ratio. Our model reproduces NREL's own PVWatts v8 reference case (Phoenix) within 0.4% for the year. Weather: NREL NSRDB and TMY3 station data.
- Charging match. Each day the car needs its average daily energy. Solar made while the car is plugged in charges it directly; the rest goes to the grid. The array is treated as serving only the car, which is conservative: in a real home some of that surplus would run other appliances.
- Export credit. "Full retail" assumes your home uses more electricity each month than the panels make, which is normal for a system sized to a car. Percentage rules rise with the retail price; fixed ¢/kWh rates are held flat for all 25 years.
- Electricity price. U.S. Energy Information Administration average residential price by state, Sep 2025 to Aug 2026. Enter your own rate from your bill for a closer answer.
- Vehicle efficiency. Natural Resources Canada 2024 combined ratings (same five-cycle test as the EPA), converted to kWh per 100 miles.
- Installed price. Default $3.00 per watt. EnergySage's marketplace averaged $2.48/W in the first half of 2025; Berkeley Lab's Tracking the Sun puts most 2023 home installs between $3.20 and $5.50/W. Small systems cost more per watt.
- Tax credit. The federal residential clean energy credit ended for homeowner-owned systems installed after 31 December 2025.
- Not included yet: time-of-use rates, cold-weather drop in EV efficiency, state and utility rebates, batteries, shading on your roof, and days when the car needs more or less than average.
- Cities available: Phoenix, AZ, Las Vegas, NV, Fresno, CA, San Francisco, CA, Denver, CO, Oklahoma City, OK, Des Moines, IA, Chicago, IL, Miami, FL, Northern Virginia (Dulles), VA, Newark, NJ, New York City, NY.
In Texas, where you can choose your electricity plan, see which Texas plans make EV charging cheapest.
Data updated 2026-10-26