Most payback calculators assume every kWh is worth your full retail rate. Here, power you use and power you export are valued separately, with no federal credit, so you can see what your state's rules do to break-even.
Same system and rates as above. Years to break even; the highlighted cell is closest to your inputs.
Bars below the line mean you are still paying the system off; above it, the system is net positive.
The 80% factor and state defaults (rate, sun hours, price per watt, export credit) match the figures on our state pages, so numbers line up across the site. Everything is editable: if you have a real quote, enter its price per watt and your bill's actual rate.
Charging an EV? See how much extra solar it needs. Adding a battery? Test it in the home battery payback calculator. Financing interest, battery cost, time-of-use rates, fixed grid fees, panel replacement and inverter replacement are not included, and the federal credit for homeowners (Section 25D) is not applied because it ended for systems placed in service after 2025. Commercial and lease structures can differ. Treat the result as a comparison tool, then check it against written quotes. For the plain bill-offset method, see the Solar Payback Period Calculator; for how export credits work, the Net Metering Calculator.
No for most homeowners: the residential clean energy credit (Section 25D) does not apply to systems placed in service after December 31, 2025. This calculator assumes no federal credit; use the rebate field for any state, utility or local incentive you qualify for.
Power you use as it's produced offsets the full retail rate. Power you send to the grid is credited at your utility's export rate, which can be much lower under net billing. The less you self-consume and the lower the credit, the longer the payback.
Without a battery, many homes self-consume roughly 30 to 60 percent of their solar output, depending on when they're home. Homes with batteries can reach 70 to 90 percent, but a battery adds its own cost, which this tool does not include.