Solar Payback Calculator by State
Enter your system size and installed price per watt, add any state or utility incentive, and get the estimated payback year and 25-year net savings for the US, with 2026 rules.
Solar payback
D01Scenario A
Sets the electricity rate. Pick US average if you're not sure.
From EIA for US average. Use the rate on your bill if you know it.
Rate used: 18.4¢/kWh · US average · EIA reference 2025–26 · 1,350 kWh per kW of solar · export rule: varies (data as of 2026-09-26) ·
2026 average before incentives is about $3.00/W.
Estimated payback
10,800 kWh a year in US average; export credit rule: varies.
- Year-1 production
- 10,800 kWh
- Year-1 savings
- $794.88
- Net cost (no federal 25D credit)
- $24,000.00
- Payback
- 23 years
- Net savings over 25 years
- $3,021.17
- Net metering factor used
- 0.4 (varies)
Estimate. Formula and sources are under “How it works”. Change any input; the result updates as you type.
2026 note: The federal 25C and 25D tax credits ended for installations after Dec 31, 2025. Our numbers use 2026 rules. State rebates, HEAR/HOMES programs and utility programs may still apply.
Formula
How it works
- Year-1 production (kWh) = system kW × your state's kWh per kW per year
- Savings in year n (n = 0, 1, 2…) = production × (1 − 0.005 × n) × rate × 1.03ⁿ × net metering factor
- Net cost = kW × 1,000 × $ per watt − state or utility incentive
- Payback = the first year in which cumulative savings reach the net cost (checked out to 30 years)
- 25-year net savings = the sum of savings for years 0–24 − net cost
No federal credit in the net cost. The federal 25D residential clean energy credit ended for systems placed in service after Dec 31, 2025, so the net cost only subtracts the state or utility incentive you enter.
The net metering factor is how much of your production is worth the full retail rate. It comes from your state's rule in our data: retail net metering = 1.0; net billing = 0.6 (about half the output exported at roughly a quarter of the retail rate); limited or utility-dependent = 0.5; anything else = 0.4. Panels lose 0.5% of output a year, and the rate is assumed to rise 3% a year. Every payback and 25-year figure is an estimate: the system size, the price per watt and the incentive are editable, and the state's production, rate and rule are shown under the result.
Sources: production per kW from NREL PVWatts v8 (tilt = latitude, south-facing, 14% losses); installed cost of about $3.00/W before incentives from LBNL Tracking the Sun and EnergySage; 0.5%/year degradation from NREL; 3%/year rate escalation from the EIA 2000–2025 history (≈2.8%); net metering rules from DSIRE and state commissions; electricity rate from EIA Electric Power Monthly table 5.6.A. 25D ended by the One Big Beautiful Bill Act (July 2025).
Worked example
A worked example
A 6 kW system in California makes an estimated 6 × 1,550 kWh = 9,300 kWh in its first year. California is on net billing (NEM 3.0), so we use a net metering factor of 0.6: at 32.0¢/kWh, the first year is worth about $1,785.60. With no federal credit, the net cost is the full 6,000 W × $3.20 = $19,200.00. Cumulative savings pass that in year 10, and after 25 years the estimate is $41,499.74 ahead of the net cost.
Reference
By state, at the default inputs
Estimated payback, with this page's default inputs and each state's reference prices (EIA reference 2025–26, data as of 2026-09-26).
| US average | 23 years | 18.4¢/kWh |
|---|---|---|
| Alabama | 22 years | 15.5¢/kWh |
| Alaska | 12 years | 25.0¢/kWh |
| Arizona | 17 years | 15.0¢/kWh |
| Arkansas | 22 years | 13.0¢/kWh |
| California | 10 years | 32.0¢/kWh |
| Colorado | 11 years | 16.0¢/kWh |
| Connecticut | 8 years | 30.0¢/kWh |
| Delaware | 13 years | 17.0¢/kWh |
| District of Columbia | 12 years | 19.0¢/kWh |
| Florida | 13 years | 15.0¢/kWh |
| Georgia | 24 years | 14.5¢/kWh |
| Hawaii | 11 years | 42.0¢/kWh |
| Idaho | 23 years | 12.0¢/kWh |
| Illinois | 13 years | 17.0¢/kWh |
| Indiana | 21 years | 15.5¢/kWh |
| Iowa | 15 years | 13.5¢/kWh |
| Kansas | 13 years | 14.5¢/kWh |
| Kentucky | 24 years | 13.0¢/kWh |
| Louisiana | 23 years | 12.5¢/kWh |
| Maine | 9 years | 26.0¢/kWh |
| Maryland | 12 years | 19.0¢/kWh |
| Massachusetts | 8 years | 29.0¢/kWh |
| Michigan | 18 years | 19.5¢/kWh |
| Minnesota | 14 years | 15.5¢/kWh |
| Mississippi | 22 years | 13.5¢/kWh |
| Missouri | 15 years | 13.0¢/kWh |
| Montana | 15 years | 13.0¢/kWh |
| Nebraska | 15 years | 12.0¢/kWh |
| Nevada | 17 years | 15.0¢/kWh |
| New Hampshire | 9 years | 27.0¢/kWh |
| New Jersey | 10 years | 22.0¢/kWh |
| New Mexico | 11 years | 15.0¢/kWh |
| New York | 10 years | 25.0¢/kWh |
| North Carolina | 21 years | 14.5¢/kWh |
| North Dakota | 17 years | 11.5¢/kWh |
| Ohio | 14 years | 16.5¢/kWh |
| Oklahoma | 14 years | 13.0¢/kWh |
| Oregon | 16 years | 14.5¢/kWh |
| Pennsylvania | 12 years | 18.5¢/kWh |
| Rhode Island | 8 years | 29.0¢/kWh |
| South Carolina | 20 years | 15.0¢/kWh |
| South Dakota | 30 years | 13.0¢/kWh |
| Tennessee | 26 years | 13.5¢/kWh |
| Texas | 21 years | 15.5¢/kWh |
| Utah | 22 years | 12.0¢/kWh |
| Vermont | 11 years | 22.0¢/kWh |
| Virginia | 13 years | 15.5¢/kWh |
| Washington | 19 years | 12.0¢/kWh |
| West Virginia | 15 years | 15.5¢/kWh |
| Wisconsin | 13 years | 17.5¢/kWh |
| Wyoming | 15 years | 12.5¢/kWh |
Questions
FAQ
Is solar still worth it in 2026 without the tax credit?
It depends on your state's rate and net metering rule far more than on the panels. At $3.00/W and 8 kW with no incentive, our estimates range from 8 years in Massachusetts (29.0¢/kWh, retail net metering) to 21 years in Texas (15.5¢/kWh, utility-dependent export credit). Pick your state for its number.
What is net billing vs net metering?
With retail net metering, every kWh you send to the grid earns a credit at the retail rate, so all your production is worth the full rate (factor 1.0). With net billing, exports earn less than retail, so the same panels are worth less (factor 0.6 in our model). California's NEM 3.0 is net billing; New York is retail in our data. The Net Metering Savings calculator shows the dollar gap for your state.
How much does solar cost in your state?
Our default is $3.00 per watt installed before incentives, about $24,000 for 8 kW (LBNL Tracking the Sun, EnergySage). Your quote may differ, so type in its price per watt; at $2.50/W the same 8 kW system in Texas pays back in an estimated 18 years instead of 21.
Does a state rebate change the payback much?
In California, a $3,000 incentive on the 6 kW example lowers the net cost from $19,200.00 to $16,200.00 and the payback from 10 to an estimated 9 years. Look up programs in your state in the DSIRE database, then enter the approved amount.
Why does the calculator say more than 30 years?
When cumulative savings don't reach the net cost within 30 years, we don't print a year. That happens with a low rate, weak sun, a limited export credit, a high price per watt, or all of them together.
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