SolarIs Solar Worth It in 2026? What Changed After the Federal Tax Credit Ended
The 25D federal credit ended for systems installed after 2025. Here is what now decides whether solar pays off, and how to estimate your own payback.
Solar panel calculator: size, cost and payback
Estimate the solar system size, cost, first-year savings and payback for your home. No federal tax credit is included, because the 25D credit does not apply to systems installed after 2025.
State rates are 12-month residential averages from EIA, through August 2026. Use the rate on your own bill for the most accurate result.
How to use the solar panel calculator
- Choose your state – its solar production per kW (NREL PVWatts), average usage and rate load automatically.
- Replace the usage and rate with the numbers on your bill.
- Adjust the installed cost per watt to match a quote you received.
- Read the system size, cost, savings and payback.
Formula
System size (kW) = annual kWh ÷ kWh produced per kW, rounded up to whole 400 W panels. Cost = size × $ per watt. Savings each year = the lower of production and your use × your rate; panels lose 0.5% output a year. Payback is when total savings pass the cost.
Worked examples
| State | kWh per kW/yr | Size for avg home | Cost | Payback |
|---|---|---|---|---|
| Hawaii | 1,622 | 4.0 kW | $10,280 | 3.8 yrs |
| California | 1,677 | 4.0 kW | $10,280 | 5.2 yrs |
| Massachusetts | 1,302 | 5.6 kW | $14,392 | 6.6 yrs |
| Rhode Island | 1,294 | 5.2 kW | $13,364 | 6.9 yrs |
| Maine | 1,319 | 5.2 kW | $13,364 | 7.1 yrs |
| New York | 1,291 | 5.6 kW | $14,392 | 7.2 yrs |
| Connecticut | 1,291 | 6.8 kW | $17,476 | 7.6 yrs |
| District of Columbia | 1,391 | 5.6 kW | $14,392 | 7.7 yrs |
| New Hampshire | 1,258 | 6.4 kW | $16,448 | 7.9 yrs |
| New Jersey | 1,305 | 6.4 kW | $16,448 | 8.6 yrs |
| Maryland | 1,392 | 8.4 kW | $21,588 | 8.9 yrs |
| New Mexico | 1,779 | 6.8 kW | $17,476 | 9.0 yrs |
Solar estimates by state
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently asked questions
How many solar panels do I need?
Divide your yearly kWh by the kWh one kW of panels produces where you live, then divide the kW by your panel size. The calculator does this using NREL production data for your state.
Is the federal solar tax credit included?
No. The residential clean energy credit (25D) does not apply to expenditures made after 31 December 2025, so these estimates include no federal credit. State or utility incentives may still apply.
How long does solar take to pay for itself?
It depends on sunshine, your electricity rate and the installed price. The table shows the states with the fastest payback for an average home under our assumptions.
Are these numbers a quote?
No. They are planning estimates. Compare real quotes, which reflect your roof, shading and local prices.
Related guides
Solar
SolarHow Many Solar Panels Do I Need? A Simple Sizing Guide
Divide your yearly kWh by production per kW to get system size, then by panel wattage to get a panel count. Worked examples and a roof-space check.
SolarSolar Lease vs Buy vs PPA: Which Is Better for You in 2026?
Owning, leasing or signing a PPA changes who gets the savings, who handles upkeep and what happens when you sell. Here is how they compare in 2026.
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Net metering credits you for solar power sent to the grid, but export rates and credit rules vary by state and utility. Here is how it works.
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