Enter your electric bill and utility rate to size a system and see honest payback math — full price, since the 30% federal tax credit expired at the end of 2025.
Updated September 2026 · Free · No sign-up
Estimate your solar payback
Recommended system size
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Cost after incentives
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Payback metric
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The 30% federal tax credit expired December 31, 2025 — this calculator assumes full price. Check dsire.org for state incentives worth real money.
What drives solar payback
Solar payback is a ratio: what you pay divided by what the panels save you every year. Both sides move:
Your utility rate: the single biggest lever. Panels offset kilowatt-hours, so power at 35¢ saves far more per kWh than power at 12¢.
Your sun: production runs from roughly 1,600 kWh per installed kW per year in the Southwest down to about 1,200 in cloudier northern markets.
Price per watt: $2.50 to $3.50 is the 2026 band. Above that, you are paying for complexity — or a fat sales margin.
Incentives: the federal credit is gone, but state credits, rebates and SREC programs now carry the weight. Verify every claimed incentive on dsire.org rather than trusting a sales deck.
How the math works
We convert your bill to kilowatt-hours with your actual rate, size the system to hit your offset target, and price it at your dollars-per-watt input. Savings grow each year with your escalation assumption and shrink about 0.5% a year to panel degradation. We subtract one string-inverter replacement (about $2,000 around year 10 to 15) inside the 25-year figure, because every string-inverter system needs it once.
Tip: if a quote still shows a 30% federal credit, walk. We've seen quotes referencing the expired credit. And never put new panels on a roof with less than 10 years left — a later removal-and-reinstall runs $3,000 to $5,000.
Is solar still worth it without the federal tax credit?
In high-rate states like Massachusetts, California or Connecticut, usually yes — paybacks of 9 to 12 years against 25-plus years of equipment life. In states where electricity runs 11 or 12 cents per kWh, the math is now marginal and sometimes negative. The 30% federal credit expired December 31, 2025, so buyers now pay full price.
How much does a home solar system cost in 2026?
Budget $2.50 to $3.50 per watt installed, or $15,000 to $25,000 for the 6 to 8 kW system most 2,000 square foot homes need. Roof complexity, steep pitch, tile roofing and a two-story layout can add $1,500 to $3,000 or more.
What payback should I expect?
Without the federal credit, expect an 11 to 15 year simple payback in many states, faster where power is expensive and slower where it is cheap. Run your own numbers: system cost divided by first-year savings, using your actual utility rate.
Should I buy with cash, a loan, or a lease?
Cash is cheapest over the system life. A solar loan gets you ownership with no upfront cost, but dealer-fee-loaded loans roll a 15 to 30% fee into the balance — compare the cash price against the loan principal. Treat leases as a last resort: you give up the savings and complicate the home sale.
