Solar + EV Payback Calculator
Estimate how long solar panels + EV home charging take to pay back for your situation. Includes combined and incremental EV modes, a payback range based on sensitivity, and a break-even electricity rate.
Your inputs
Your result
Enter your state, electricity rate, and EV to see your estimate.
How this calculator works
- Annual EV energy = (annual miles ÷ 100) × EV kWh/100 mi.
- Solar production = system kW × kWh/kW/yr.
- Self-consumed solar = production × self-consumption %; remainder is exported.
- Annual savings = (self-consumed kWh × retail rate) + (exported kWh × export rate).
- Net system cost = (kW × $/W × 1000) + charger cost − confirmed incentives.
- Simple payback = net system cost ÷ annual savings.
- Existing-solar mode: payback = (charger cost − incentives) ÷ incremental EV savings (with EV minus without EV).
Assumptions
- Solar production default (1,400 kWh/kW/yr) is a national mid-range assumption. Verify for your location at NREL PVWatts.
- Self-consumption default (70%) is an assumption. Users with high EV demand may need to increase it; users with net metering may need to decrease it.
- Rate escalation default (3%/yr) is an assumption. US residential rates rose about 7.3% year-over-year in some regions (EIA, April 2026).
- EV efficiency values are 2026 EPA estimates. Verify for your model year at fueleconomy.gov.
- Existing-solar mode assumes 30% of existing production is available for EV charging after home load — a simplifying assumption.
- The federal residential solar credit (Section 25D) expired Dec 31, 2025. This calculator does not apply it. Enter confirmed state or utility incentives manually.
- State electricity rates are not auto-filled. Enter your actual rate from your utility bill — US state averages change monthly and this tool cannot verify them reliably.
- If net billing is selected and no export rate is entered, the tool uses min(retail × 0.2, 5)¢/kWh as a labeled conservative fallback.
What this calculator does not model
- Inverter replacement (typically year 10–15).
- EV battery degradation over time.
- Detailed time-of-use rate arbitrage.
- Resale value of solar or EV.
- Mid-horizon policy changes.
- Utility EV-specific rate schedules (unless you enter them manually).
Solar + EV Payback Calculator (2026-2027): See Your Real Break-Even by State, Utility, and Vehicle
This page estimates how long it takes for solar panels plus EV home charging to pay back in your situation. It accounts for the federal residential solar credit that expired on December 31, 2025, your state’s electricity rate, your utility’s export regime, your EV’s efficiency, and the cost of installing a Level 2 charger.
For a typical US homeowner driving 12,000 miles a year in an EV that uses about 28 kWh per 100 miles, solar + EV payback is commonly modeled in the 8–14 year range without the federal solar credit, depending mainly on state electricity rates and how your utility credits exported solar. That is a modeled range, not a prediction for your specific home. Your electricity rate and your utility’s export regime matter most.
Open the Solar + EV Payback Calculator to enter your state, rate, EV, and system details and see a personalized estimate, a payback range, and a break-even electricity rate.
What your result means
Payback is the point where cumulative savings equal the net cost of the solar system plus the charger installation, after any confirmed incentives. A shorter payback is generally better, but the right decision depends on how long you plan to stay in the home and how confident you are in the assumptions.
If your payback is under 8 years
At current 2026 economics, a sub-8-year payback usually means a high electricity rate, strong solar production, a favorable export regime, or a low installed cost per watt. These conditions are most likely in states with above-average residential rates and reasonable solar output.
If your payback is 8–12 years
This is a common modeled range for US homeowners after the federal credit expired. It does not mean the investment is bad. It means the economics depend more heavily on rate escalation, export policy, and how long you keep the system.
If your payback is over 12 years
A longer payback can still make sense if you plan to stay in the home, if your utility’s export rules are likely to improve, or if you value resilience and fixed energy costs. But it is a signal to check your electricity rate and export regime carefully before proceeding.
How to interpret the range
The calculator shows a low–high range, not a single number, because electricity rates, system costs, and export policies vary. If the range is wide, your decision is more sensitive to assumptions. If the range is narrow, the result is more stable.
How this calculator works
The methodology is deliberately simple and reproducible. Every input is either entered by you or disclosed as an assumption.
Step 1 — Calculate your EV’s annual energy use
Annual EV energy (kWh) = (annual miles ÷ 100) × EV efficiency (kWh/100 mi). For example, 12,000 miles at 28 kWh/100 mi uses 3,360 kWh per year. The calculator uses 2026 EPA efficiency estimates for popular models and lets you enter your own value if you choose manual entry.
Step 2 — Estimate solar production for your state
Solar production (kWh/yr) = system size (kW) × state production (kWh/kW/yr). State production comes from NREL’s PVWatts v8 model at a representative city per state. The calculator uses a national mid-range default and lets you adjust it. Output is assumed to degrade by 0.5% per year, a standard NREL assumption.
Step 3 — Apply your net-metering regime
Solar production is split into self-consumed energy and exported energy. Under full retail net metering, exported solar is credited at your retail rate. Under net billing or avoided-cost export, exported solar earns a lower export rate. Under no export credit, exported solar earns nothing. The self-consumption percentage is an editable assumption; the default is 70%.
Step 4 — Calculate net system cost
Net system cost = (system kW × $/W × 1,000) + charger installation cost − confirmed incentives. The federal residential solar credit (Section 25D) expired on December 31, 2025, so the calculator does not apply it. You enter only incentives you have confirmed.
Step 5 — Compute payback and 25-year savings
Simple payback = net system cost ÷ net annual savings. The calculator also shows a 25-year nominal savings estimate and a break-even electricity rate — the rate at which payback would equal 10 years at your other inputs.
Formula reference
All formulas are listed in the calculator’s “How this calculator works” section and repeated in the assumptions below. No hidden adjustments are made.
Assumptions and data sources
Every time-sensitive data point should be verified before you rely on it. The following assumptions are used in the calculator and in the modeled ranges on this page.
Electricity rates
US residential electricity averaged about 18.19¢/kWh from January through July 2026, according to the US Energy Information Administration’s Electric Power Monthly Table 5.6.B. State averages vary widely: North Dakota was about 12.36¢/kWh, while Maryland was about 21.30¢/kWh in the same period. Your own utility bill is the correct input for your home, not a state average.
Solar production
State-level production ranges come from NREL PVWatts v8 at one representative city per state, assuming a south-facing roof at a 20° tilt with standard losses. First-year production ranges from roughly 810–920 kWh/kW in Alaska to 1,680–1,820 kWh/kW in Arizona. The calculator uses 1,400 kWh/kW/yr as a labeled national mid-range default.
Incentives
The Section 25D residential clean energy credit expired for systems placed in service after December 31, 2025, under the One Big Beautiful Bill Act. State and utility incentives vary and change frequently. Check DSIRE for your state and enter only amounts you have confirmed.
EV efficiency
Efficiency values are 2026 EPA estimates. A 2026 Tesla Model Y, for example, ranges from about 24 kWh/100 mi on the Standard RWD to about 32 kWh/100 mi on the Performance trim. Verify your exact model year at fueleconomy.gov.
System cost
Lawrence Berkeley National Laboratory’s Tracking the Sun data show a US residential median installed cost of roughly $2.58–$3.25 per watt in 2026, before incentives. The calculator defaults to $2.80/W and lets you adjust it.
What this calculator does not model
- Inverter replacement (typically in year 10–15).
- EV battery degradation over time.
- Detailed time-of-use rate arbitrage.
- Resale value of the solar system or the EV.
- Mid-horizon policy changes.
- Utility-specific EV charging rate schedules unless you enter them manually.
State-level payback ranges (2026)
The table below shows a representative subset of states, not all 50. Rates are 2026 year-to-date EIA averages; production ranges come from NREL PVWatts v8. The modeled payback range assumes a 6 kW system at $2.90/W, a $800 charger installation, a 12,000-mile EV at 28 kWh/100 mi, 70% self-consumption, no federal credit, and no state incentive entered. It is an illustrative model, not a quote or a prediction for a specific home.
| State | Avg. residential rate (EIA, 2026 YTD) | Solar production (kWh/kW/yr, PVWatts v8 range) | Net-metering note | Modeled payback range (illustrative) |
|---|---|---|---|---|
| North Dakota | 12.36¢/kWh | 1,070–1,200 | Voluntary utility net metering; export treatment varies | Roughly 12–18 years under these assumptions |
| Louisiana | 13.35¢/kWh | 1,340–1,490 | Entergy retail net metering in many territories | Roughly 10–15 years |
| Florida | 15.30¢/kWh | 1,400–1,560 | Full retail net metering in many utility territories | Roughly 9–14 years |
| Arizona | 15.44¢/kWh | 1,680–1,820 | Net billing for some utilities (e.g., APS); export credit below retail | Roughly 9–14 years, wider if export credit is low |
| Texas | 16.06¢/kWh | 1,380–1,540 | Utility-dependent; some retail net metering, some lower export credit | Roughly 9–14 years |
| Illinois | 19.22¢/kWh | 1,050–1,200 | Full retail net metering plus SREC/PBI programs in many areas | Roughly 10–16 years before state incentives |
| Maryland | 21.30¢/kWh | 1,140–1,280 | Full retail net metering plus SREC market | Roughly 9–15 years before state incentives |
How to read this table: A higher electricity rate and higher solar production generally shorten payback, but the export regime can change the result by several years. The ranges above are wider than a single-point estimate because real homes vary in rate, roof orientation, shading, and utility policy. Use the calculator with your own inputs for a closer estimate.
Incremental EV payback vs. combined payback
Most calculators report a single “combined” payback that treats the entire solar system and the EV as one investment. That is useful if you are buying both at the same time. It is misleading if you already own solar and are only adding an EV charger.
Combined payback
This is the payback of the full solar + charger investment: total net system cost divided by total annual savings from solar production and EV charging.
Incremental EV payback
This is the payback attributable to the EV alone when you already have solar. The investment is the charger installation cost (plus any incremental solar capacity, if you add panels). The savings are the difference between your energy bill with the EV and your bill without it. If your existing solar already produces more than your home uses, adding an EV may absorb otherwise-exported energy and produce a very different payback than a combined calculation would suggest.
Worked example
Suppose you already have a 6 kW system that produces 8,400 kWh per year, self-consume 70%, and export 30% at full retail. Adding an EV that uses 3,360 kWh per year could absorb a portion of the exported energy. The incremental savings depend on how much solar would otherwise be exported and what that export is worth. The calculator’s existing-solar mode isolates this difference instead of lumping it into a combined number.
Net metering vs. net billing: why your export rate changes everything
The way your utility credits exported solar is often the single largest variable after your electricity rate. Two homes on the same street with the same solar system can see materially different paybacks because their utilities use different export rules.
Full retail net metering
Every exported kWh is credited at your full retail rate. Under this regime, diverting solar to your EV instead of exporting it produces little or no incremental energy-bill benefit, because the exported kWh would have been credited at the same rate.
Net billing (avoided-cost export)
Exported kWh earn a lower rate than you pay for imports — often an avoided-cost or feed-in rate. Under net billing, self-consuming solar is more valuable than exporting it. Diverting solar to your EV can produce real incremental savings because it avoids a retail-rate import.
No export credit
Exported solar earns nothing. In this case, maximizing self-consumption is critical, and the EV becomes a way to use solar energy that would otherwise be wasted from a bill perspective.
How to find your utility’s policy
Check your utility’s net-metering or distributed-generation tariff page. DSIRE also summarizes state rules. If you cannot find a clear answer, enter “no export credit” in the calculator as a conservative assumption and note that your actual result may be better.
Daytime solar charging vs. overnight grid charging
When you charge your EV matters as much as how much solar you install. The table below summarizes the trade-off in general terms. Actual results depend on your utility’s rates and export rules.
| Strategy | How it works | When it tends to win | When it may not |
|---|---|---|---|
| Daytime solar charging | Charge while the sun is producing, maximizing self-consumption | Net billing or no export credit; high retail rate; home during the day | Full retail net metering, where exported solar is already credited at retail |
| Overnight grid charging | Charge at night, often on a time-of-use EV rate, and export solar during the day | Full retail net metering; low overnight EV rate; TOU arbitrage | Net billing with low export credit; no TOU rate available |
The calculator’s daytime vs. overnight comparison is a modeled estimate. It does not replace a review of your specific utility tariff.
Sensitivity: what changes your payback most
Based on the calculator’s methodology and the variation observed across US utilities, the inputs that most often change the result are, in order:
- Electricity rate. A higher retail rate increases savings per self-consumed kWh and shortens payback.
- Export regime. Full retail net metering, net billing, and no export credit can shift payback by several years.
- System cost ($/W). Every $0.25/W on a 6 kW system changes the gross cost by about $1,500 and can move payback by roughly 0.8 years.
- Annual miles driven. More EV miles increase the EV load and the potential savings, but only if the solar can cover that load.
- EV efficiency. A less efficient EV uses more kWh per mile, which increases the value of solar charging if you are displacing retail-rate electricity.
What this means for your decision: If your result is borderline, focus on confirming your actual electricity rate and your utility’s export policy before optimizing system size or EV choice.
Frequently asked questions
Is charging an EV with solar worth it?
It can be, especially if you have a high electricity rate, good solar production, and an export regime that rewards self-consumption. It is less attractive if your rate is low, your utility offers full retail net metering (so exported solar is already valuable), or your installed cost per watt is high.
How many solar panels do I need for an EV?
A 12,000-mile EV at 28 kWh/100 mi uses about 3,360 kWh per year. In a state producing 1,400 kWh/kW/yr, that is roughly 2.4 kW of solar capacity dedicated to the EV, before accounting for home load and self-consumption. A 6 kW system is a common starting point for combined home and EV use, but sizing depends on your goals.
EV vs gas: how much do I save?
Fuel savings depend on your electricity rate, gasoline price, and vehicle efficiency. The calculator focuses on solar payback rather than a full EV-vs-gas comparison. For a fuel-cost comparison, use the EV home charging cost calculator and compare with your current gasoline spending.
What is a good solar payback period?
There is no universal answer. A shorter payback reduces financial risk, but a longer payback can still be reasonable if you plan to stay in the home and value fixed energy costs. Many US homeowners now see modeled paybacks in the 8–14 year range after the federal credit expired, depending on state and utility.
How accurate is this calculator?
It is an estimate based on your inputs and disclosed assumptions. It does not replace a quote from an installer or a review of your utility bill and tariff. The state-level table uses modeled ranges, not predictions for a specific home.
Why did the federal solar tax credit disappear?
The Section 25D residential clean energy credit expired for systems placed in service after December 31, 2025, under the One Big Beautiful Bill Act (P.L. 119-21). Homeowner-owned systems installed in 2026 generally do not qualify for the 30% federal credit. Some third-party-owned systems may still be eligible for a different commercial credit, but that is outside the scope of this calculator.
How much does it cost to charge an EV with solar?
If the solar energy is self-consumed, the marginal cost is effectively zero after the system is paid for. If you are evaluating the cost before payback, the relevant figure is your net system cost divided by the kWh the system produces over its life, not a simple per-kWh charge.
Solar vs grid EV charging — which wins?
Solar charging wins when self-consumption is valuable and your export credit is low. Grid charging can win when you have full retail net metering, a low overnight time-of-use rate, or a solar system that already exports more than it self-consumes.
Does my utility’s net-metering policy change the payback?
Yes. It is one of the largest variables. Full retail net metering, net billing, and no export credit can produce materially different paybacks for the same solar system and EV.
I already have solar. Is adding an EV charger worth it?
Use the existing-solar mode in the calculator. The incremental payback depends on how much of your existing solar production the EV can absorb, what that energy would otherwise be worth, and the charger installation cost.
Should I charge my EV during the day from solar or at night from the grid?
It depends on your export regime and time-of-use rates. If exports are credited at full retail, overnight charging plus daytime export may be equally attractive. If exports are credited below retail or not at all, daytime solar charging usually captures more value.
Does the expired 30% tax credit kill the math?
It lengthens payback for homeowner-owned systems, but it does not automatically make solar + EV uneconomic. The impact depends on your state rate, system cost, and export regime. The calculator excludes the expired credit and lets you enter confirmed state or utility incentives separately.
What state has the fastest solar + EV payback?
States with high electricity rates and strong solar production tend to have shorter modeled paybacks, but export policy matters just as much. The state table above shows a representative subset; your own rate and utility tariff are more important than the state average.
How much does Level 2 charger installation add to the payback?
A Level 2 charger installation commonly adds several hundred to a few thousand dollars depending on panel capacity, wiring distance, and local labor. The calculator includes this cost in the net system cost so it is not ignored.
What happens to payback in a cloudy climate?
Lower solar production increases payback unless electricity rates are high enough to compensate. Use a lower kWh/kW/yr value in the calculator to approximate your location, or check NREL PVWatts for a site-specific estimate.
Related tools and guides
- EV Charger Installation Cost + Panel Decision Estimator — get an itemized Level 2 charger installation range and a panel-upgrade decision flag.
- EV Ownership Cost Calculator (USA) — estimate monthly and 10-year ownership costs, including charging, insurance, and maintenance.
- EV Cost Per Mile Calculator — calculate your true running cost per mile and compare home vs public charging.
- EV vs Gas Car Savings Calculator — find your break-even year when switching from a gas car to an EV.
- EV Range Calculator by Temperature — see how cold and heat affect real-world range for your model.
- EV Battery Aging Calculator — estimate battery degradation, range loss, and lifespan based on age, mileage, and charging habits.
Sources and methodology
Last verified: October 2026. This page should be rechecked when EIA releases new monthly rates, when NREL updates PVWatts, and when state or federal incentive rules change.
- Electricity rates: US Energy Information Administration, Electric Power Monthly, Table 5.6.B, 2026 year-to-date (January–July). US average 18.19¢/kWh; state averages as cited.
- Solar production: NREL PVWatts v8, representative city per state, south-facing 20° tilt, standard losses.
- Federal solar policy: Section 25D expired for systems placed in service after December 31, 2025 (One Big Beautiful Bill Act, P.L. 119-21).
- EV efficiency: US EPA fueleconomy.gov, 2026 model year estimates.
- System cost: Lawrence Berkeley National Laboratory, Tracking the Sun, 2024 installations, as reported in 2026 industry summaries; median range $2.58–$3.25/W before incentives.
- Incentives: DSIRE (Database of State Incentives for Renewables & Efficiency); individual state and utility program pages.
Correction policy: If you find an error, contact us. We will correct it and date the correction.
Disclaimer: This is an estimate, not a quote or financial advice. All calculations depend on your inputs and the assumptions disclosed above. Verify all rates and incentives with your utility and a qualified installer before making decisions. Modeled payback ranges in the state table are illustrative and are not predictions for a specific home.
Authoritative sources
- U.S. Energy Information Administration — Electric Power Monthly — Source for state-level residential electricity rates (Table 5.6.B).
- NREL PVWatts Calculator — Official NREL tool for estimating solar production by location.
- DSIRE — Database of State Incentives for Renewables & Efficiency — Comprehensive database of state, local, and utility incentives.
- FuelEconomy.gov — Official U.S. Government Source for Fuel Economy — EPA/DOE data for EV efficiency (kWh/100 mi) by model year.
- Berkeley Lab — Tracking the Sun — LBNL report series on U.S. residential solar installed costs.