Assumes 3%/yr rate increases, 0.5%/yr panel degradation and no federal tax credit (the 30% §25D credit ended for systems installed after Dec 31, 2025). How we calculate
Data approachEIA rates · NREL sun hours · 2026 federal policy · methodology
Short answer: Charging an EV with home solar costs about 2.5¢ per mile over a 25-year system life, compared with about 5.5¢ per mile on average U.S. grid power and about 14.9¢ per mile for a 30-mpg gas car at today’s $4.47 per gallon. A driver covering 12,000 miles a year needs about 3,600 kWh, or roughly 7 extra 400-watt panels. The catch in 2026: homeowners who buy solar no longer get the 30% federal tax credit, so payback depends mostly on what your utility charges per kWh.
Key facts (updated October 1, 2026):
U.S. average residential electricity price: 18.31¢/kWh in July 2026 (EIA).
U.S. average regular gasoline: $4.47/gal for the week of September 28, 2026 (EIA).
Typical installed solar cost: $2.50–$3.50 per watt in 2026, before incentives.
The federal residential solar credit (Section 25D) ended for systems placed in service after December 31, 2025.
The federal home charger credit (Section 30C) ended for chargers placed in service after June 30, 2026.
Solar EV charging works by sending panel output to your car when the sun is up, or by earning utility bill credits for exported power that you later use to charge. The average U.S. household bought about 10,260 kWh of electricity in 2023, or roughly 855 kWh a month (EIA, via the EPA). An EV driven 12,000 miles adds about 3,600 kWh on top of that. This guide shows the math behind cost per mile, panel count, payback and annual savings, so you can plug in your own numbers.
💰 Cost per Mile
What Does It Cost to Charge an EV With Solar Panels?
Solar charging costs about 2.5¢ per mile when you spread the cost of the panels over the electricity they produce in 25 years. That compares with about 5.5¢ per mile when the same EV charges on average grid power and about 14.9¢ per mile for a 30-mpg gas car.
The solar figure comes from a simple levelized calculation. A $2.75-per-watt system costs $2,750 per kW. In an average-sun location it produces about 1,400 kWh per kW in year one, falling about 0.5% a year, for roughly 33,000 kWh over 25 years. That works out to 8.3¢ per kWh. An EV using 30 kWh per 100 miles then costs 2.5¢ per mile. The full assumptions are listed in the Methodology section below.
Data visualization
Fuel cost per mile, 2026. Home solar charging costs about 2.5¢ per mile versus 5.5¢ on grid power and 14.9¢ for a 30-mpg gas car. Assumes $4.47/gal, 18.31¢/kWh, 30 kWh per 100 miles and a 25-year levelized solar cost with no incentives. Source: EIA, DOE AFDC, NREL PVWatts.
Chart summary: Solar-charged driving costs about one-sixth as much per mile as gasoline and about half as much as charging on the average grid rate. Over 12,000 miles that is roughly $300 a year with solar’s levelized cost, $659 on grid power, and $1,786 on gasoline. Gas prices swing more than electricity prices, so rerun the comparison with the current pump price.
Solar costs vary by market. Recent 2026 pricing guides and marketplace data put typical installed prices between $2.50 and $3.50 per watt, with competitive markets such as Texas and Arizona at the low end and the Northeast at the high end. A home charger is a separate cost. Installation prices depend heavily on your electrical panel, so get an electrician’s quote. The federal charger credit expired on June 30, 2026.
If you lease your system or sign a power purchase agreement (PPA), you pay a per-kWh rate to the provider instead of buying the panels. Compare that rate with your grid price over the full contract term, including any annual escalator.
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⚡ System Size
How Many Solar Panels Do You Need to Charge an EV?
Most drivers need about 5 to 9 additional 400-watt panels, depending on annual mileage. The formula is: annual miles × kWh per mile ÷ (panel kW × local kWh per kW per year).
At 30 kWh per 100 miles and about 1,400 kWh per kW per year, one 400-watt panel produces about 560 kWh a year. The EPA’s reference “average sun” run in NREL’s PVWatts calculator (Kansas City, Missouri) yields about 1,430 kWh per kW per year. Sunnier states produce more and cloudier ones less, so check your address in PVWatts.
Annual miles
EV charging need (30 kWh/100 mi)
Extra 400 W panels (rounded up)
Capacity needed
8,000
2,400 kWh
5
about 1.7 kW
12,000
3,600 kWh
7
about 2.6 kW
15,000
4,500 kWh
9
about 3.2 kW
EV efficiency matters. The Department of Energy’s Alternative Fuels Data Center says light-duty EVs use roughly 25 to 40 kWh per 100 miles depending on the vehicle and how it is driven. A compact sedan at 25 kWh per 100 miles needs about a sixth fewer panels than the table shows, while a large truck at 40 kWh per 100 miles needs about a third more. For more on this topic, see our guide to Solar Panels for a 1,500 Sq Ft House.
Where utilities pay less for exported power than they charge for imports, as in California under its 2023 net billing rules, matching charging to solar production hours matters more. A home battery can shift daytime production to evening charging, but it adds thousands of dollars to the project, and the federal credit that once covered batteries ended with 25D. Use our solar system size calculator to size a system for your whole home plus the car.
📈 Payback Period
Calculating the Solar EV Charging Payback Period
Simple payback equals the system cost per kW divided by its yearly output times your electricity price. At $2.75 per watt, 1,400 kWh per kW and the U.S. average of 18.31¢ per kWh, that is about 10.7 years with no federal credit, no rate increases, and every kWh valued at the retail rate. System size does not change the result, because cost and output both scale with kW. For a full cost breakdown by state and system size, see our guide to How Much Do Solar Panels Cost in 2026?.
Your electricity price changes it a lot. The chart applies the same cost and sun assumptions to five real July 2026 residential rates.
Data visualization
Simple payback by local electricity price. A $2.75/W system pays back in about 10.7 years at the 18.31¢ U.S. average and 4.1 to 15.4 years across five states. Assumes 1,400 kWh per kW per year, no federal credit, all output valued at retail. California and Hawaii export rules can lengthen real payback. Source: EIA July 2026 rates, NREL PVWatts.
Chart summary: Paybacks run from about 4 years at Hawaii’s 48¢ per kWh to about 15 years at Louisiana’s 12.7¢. Texas lands near 12 years and the U.S. average near 11 years. The California and Hawaii bars are best-case because export compensation in both states differs from simple retail net metering.
The incentive picture changed sharply. The One Big Beautiful Bill Act, signed July 4, 2025, ended the 30% residential credit (Section 25D) for systems placed in service after December 31, 2025. If you buy solar in 2026, the quote is close to your net cost, apart from state or utility programs. Lease and PPA providers may still claim a commercial credit (Section 48E) under deadlines and sourcing rules, so some offers can be priced below ownership. Ask any provider how its pricing is built and read the contract’s escalator clause. Search DSIRE for state and local programs; our incentive calculator lists what applies by state.
One more lever: if your utility buys exported power at, say, 5¢ per kWh but charges you 18¢ to import, then using solar directly in your car is worth far more than exporting it. That is why timing matters (see the last section).
The line chart below shows the cumulative cash position of the 10 kW example system, which costs $27,500 and produces 14,000 kWh in year one. It uses two electricity-price paths because future rates are the largest unknown.
Data visualization
Cumulative cash flow of a 10 kW system over 25 years. Starting at minus $27,500, the system reaches break-even in year 11 at a flat 18.31¢ rate and reaches $32,883 net by year 25. With 3% yearly rate increases it breaks even in year 10 and nets $59,890. Assumes no federal credit and 0.5% yearly output decline. Source: EIA July 2026 rate, NREL PVWatts, model.
Chart summary: At today’s U.S. average rate the example system turns cash-positive in year 11, and each year after adds about $2,300 to $2,400. If rates climb 3% a year, break-even moves up to year 10 and the 25-year total nearly doubles. Both lines exclude financing, maintenance and inverter replacement.
Solar vs utility company · 25-year comparison
25-year totals: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
What Solar EV Charging Saves Each Year: Worked Examples
These are model results from stated assumptions, not survey results. Your numbers will differ with your rates, mileage and sun.
Example 1: Solar added just for the car. A driver covers 12,000 miles at 30 kWh per 100 miles, which is 3,600 kWh a year. About 2.6 kW of extra panels (7 once rounded up) at $2.75 per watt costs roughly $7,100. At 18.31¢ per kWh that avoids about $659 a year of grid charging, so simple payback is about 10.7 years. For comparison, a 30-mpg gas car driven the same 12,000 miles burns about $1,786 of gasoline at $4.47 per gallon. Switching to an EV on grid power saves about $1,127 a year in fuel, and solar-charging removes the remaining $659.
Example 2: One system for the house and the car. A 10 kW system (about 25 panels) costs about $27,500 at $2.75 per watt. It makes about 14,000 kWh in year one, which closely matches a typical home’s 10,260 kWh plus 3,600 kWh for the EV. At a flat 18.31¢ per kWh, with every kWh valued at retail, that avoids about $2,563 of grid power in year one. With 0.5% annual output decline, 25 years of production is worth about $60,400, or roughly $32,900 more than the system cost. That excludes financing, maintenance, inverter replacement, and future rate changes in either direction.
Net metering terms drive these results. If your utility credits exports at retail, solar produced at noon can offset evening charging. If it pays much less, you need to charge when the panels produce.
⚙️ Savings Tips
How to Maximize Your Solar EV Charging Savings
Charge when the sun is out. Most home systems peak in the middle of the day. Scheduling the car to charge at midday, or using a smart charger that follows solar output, avoids low-value exports. This costs little or nothing.
Know your export rate before you size the system. Ask your utility how it credits exported kWh and whether time-of-use rates apply. If exports earn near-retail credit, size to your total annual use. If they earn far less, favor daytime self-consumption.
Size for the car you will drive. If you are about to buy an EV, include its 3,000–4,500 kWh a year in the quote request. Adding panels later can cost more per watt than including them at installation.
Compare financing options. With no homeowner credit in 2026, compare a cash purchase, a loan, and a lease or PPA on total cost over the term.
Look up local incentives. State, municipal and utility programs vary widely. Search DSIRE for your address.
Watch bidirectional charging. Some current EVs support vehicle-to-home power, which lets the car’s battery serve the house in the evening. Check that your car, charger and utility all support it.
Ready to run your own numbers? Our solar EV charging savings calculator takes your rate, mileage and sun hours and returns payback and 25-year savings.
Methodology, Assumptions and Sources
All cost-per-mile, panel-count, payback and savings figures are our own model calculations using the inputs below. They are estimates, not quotes. Last reviewed October 1, 2026.
Input
Value used
Basis
Installed solar cost
$2.75 per watt
Midpoint of the $2.50–$3.50 range in 2026 pricing guides and marketplace data
Federal credit
None
Section 25D ended for systems placed in service after Dec 31, 2025
Solar yield
1,400 kWh per kW per year
Rounded from NREL PVWatts reference run (about 1,430 in Kansas City, MO)
Output decline
0.5% per year
Common industry planning assumption; 25-year life
Electricity price
18.31¢ per kWh
EIA U.S. average residential, July 2026
EV efficiency
30 kWh per 100 miles
Within the 25–40 kWh range reported by AFDC
Annual driving
12,000 miles
Round-number assumption; table shows 8,000 and 15,000
Gas car
30 mpg at $4.47 per gallon
EIA weekly U.S. regular price, week of Sept. 28, 2026
DSIRE: Database of State Incentives for Renewables & Efficiency
This guide is general information, not tax, legal or financial advice. Confirm incentive eligibility with a qualified tax professional and get written quotes from licensed installers.
Related calculators
Free tools for US homeowners — instant results, all 50 states.
Direct answers for US homeowners — sized for a $157/month electric bill.
About 2.5¢ per mile over a 25-year system life, versus about 5.5¢ per mile on average U.S. grid power (18.31¢/kWh, EIA, July 2026) and about 14.9¢ per mile for a 30-mpg gas car at $4.47 per gallon (EIA, Sept. 28, 2026). This assumes $2.75 per watt installed, 1,400 kWh per kW per year, 30 kWh per 100 miles, and no incentives. After the system pays for itself, fuel cost approaches zero apart from maintenance.
For 12,000 miles a year, most EVs need about 3,600 kWh, which is roughly 7 additional 400-watt panels (about 2.6 kW) in an area with average sun. Drivers covering 8,000 miles need about 5 panels and 15,000 miles about 9. Use this formula: annual miles × kWh per mile ÷ (panel kW × local kWh per kW per year). Efficient EVs need fewer panels; large SUVs and trucks need more.
Mostly no. The 30% residential solar credit (Section 25D) does not apply to systems placed in service after December 31, 2025, and the home EV charger credit (Section 30C) does not apply to chargers placed in service after June 30, 2026. Federal EV purchase credits also ended for vehicles acquired after September 30, 2025. State, local and utility incentives may still apply, so check DSIRE. Lease and PPA providers may use a different commercial credit.
It can be, but the payback depends mainly on your electricity price. At the U.S. average of 18.31¢ per kWh and $2.75 per watt, the simple payback is about 10.7 years without incentives. It is about 12 years at Texas-level rates and about 15 years at Louisiana-level rates. It is much shorter where power costs 30¢ or more per kWh, if exports are credited fairly. Most homeowners get a better return from one system sized for the whole house plus the car.
Not with a standard grid-tied system. Panels only produce in daylight, and grid-tied inverters shut down during outages for safety. To use solar power at night or in an outage you need a home battery or a bidirectional (vehicle-to-home) setup. A 10 kWh battery delivers roughly 30 miles of range at 30 kWh per 100 miles, so most owners charge midday or rely on net metering credits.
$157/month electric bill by state
System size and payback vary by electricity rate and sun hours — see your state.
18.19¢/kWh — US average residential price. Source: EIA Electric Power Monthly, Table 5.6.B (year-to-date through July 2026), residential average retail price (July 2026) (EIA)
Solar production
4.5 peak sun hours/day × 0.82 system derate. Approximate state-average daily solar resource (peak sun hours) based on NREL solar resource data (NSRDB); not location-specific — use NREL PVWatts for an address-level estimate. (NREL PVWatts)
Installed price
$3.00 per watt before incentives. Blended 2026 US residential installed price used by this site; EnergySage marketplace reported about $2.60/W (mid-2026); full-market medians are higher.
Federal tax credit
$0 for homeowner-owned systems installed in 2026 — the 30% §25D credit ended Dec 31, 2025 (IRS)
Net metering
National blend — solar assumed to offset 75% of the bill (87% in full-retail net-metering states, 55–70% elsewhere).
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.