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CalculatorRates verified August 2, 2026

Solar Payback Calculator

Pick your state (rates pre-loaded from EIA data), set your system size and price, and see what your solar power actually costs per kWh, how long it takes to pay for itself, and what you net over 25 years.

Run the numbers

Solar Payback Calculator

Live August 2026 data: state electricity rates (EIA) and marketplace pricing (EnergySage). Every field is editable.

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System cost (no federal credit in 2026)
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Production, year 1
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Bill savings, year 1
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Pays for itself in
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Net savings over 25 years
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Your solar electricity costs

 

Assumes 0.5%/year panel degradation and no electricity-price inflation — both conservative: rising rates shorten payback, and this ignores maintenance or an inverter replacement, which lengthen it. Production varies hugely by location (roughly 1,000–1,200 kWh per kW in the Pacific Northwest and Northeast, 1,300–1,450 in the Southeast, up to ~1,800 in the desert Southwest) — run your address through NREL PVWatts and put the real figure in. Rates: EIA Electric Power Monthly (May 2026). Pricing: EnergySage Marketplace, both retrieved August 2, 2026. Section 25D expired for installations completed after December 31, 2025, so no federal credit is applied. Estimates only, not a quote.

How the math works

Solar is a power plant you buy up front, so the honest way to judge it is cost per kilowatt-hour — the same unit your utility bills you in:

  • System cost = system size in watts × your price per watt. No federal credit is applied: Section 25D expired for installations completed after December 31, 2025.
  • Year-1 production = system size (kW) × annual production per kW. That production figure is the weakest input in any solar estimate — get yours from NREL PVWatts rather than a national average.
  • Annual savings = production × the share you actually use at retail rate × your electricity rate.
  • Payback is computed year by year with 0.5%/year panel degradation applied, not as a flat cost ÷ year-one-savings shortcut, so the crossover year is accurate.
  • Cost per kWh = system cost ÷ total kWh you use over 25 years. Compare it directly against your utility rate — if it's lower, you're ahead.

The calculator deliberately assumes no electricity-price inflation, which is conservative: rates rose about 6% nationally in the past year, and persistent rises pull payback in. It also excludes maintenance and an eventual inverter replacement (roughly $1,500–$3,000 around year 12–15), which push it out.

Data sources & dates

Electricity rates for all 50 states plus D.C. come from the U.S. Energy Information Administration's Electric Power Monthly(May 2026 data, the latest available state-level figures), retrieved August 2, 2026. The default price per watt is the EnergySage Marketplace national average of $2.60/W (updated June 30, 2026) — note that quotes from a single door-to-door installer often run nearer $3.50/W, which is worth two to three years of payback on its own. Rates and pricing change; this page is re-verified on a schedule.

Related reading

For the full picture, read is solar worth it in 2026, the 51-state payback table, the complete solar cost breakdown, and what happened to the federal solar tax credit.