Solar Payback Calculator (2026 rules)

The 30% federal residential solar credit (25D) ended December 31, 2025. Most calculators online still include it. This one doesn't.

Estimates use typical statewide production factors. Get a per-roof estimate from NREL's PVWatts before signing anything.

Your state

System size (kW)

Installed cost ($/watt)

State/utility incentives ($, if any)

Check what your state still offers. The federal credit is gone but some states pay.

Net system cost

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Year-1 bill savings

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Simple payback

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Honest assumptions

Production = system size × your state's typical annual output per kW (derived from NREL modeling). Savings = production × your state's current residential rate, assuming most generation offsets your own use. Real-world payback depends on your roof, shading, and your utility's export compensation, which has been cut sharply in several states.

Without the federal credit, payback in cheap-electricity states can exceed 15 years, but in high-rate states with good sun it can still be under 9. Rising electricity prices shorten payback every year the trend holds.