Solar Payback Calculator
See how long a rooftop system takes to break even: install cost minus the federal credit, against what the production is worth at your state's rate.
cost/W × size − ITC
production × rate × value
years to break even
3% rate escalation, 0.5%/yr degradation
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
What actually drives solar payback
Payback is net cost divided by annual savings, and each side has one dominant lever. On cost, the federal Investment Tax Credit takes 30% off the top for qualifying homeowners, turning a $19,600 install into roughly $13,700. On savings, your utility rate matters more than your sunshine: a system in Massachusetts at 31¢/kWh pays back faster than the same roof in sunnier Arizona at 15¢, because every produced kWh offsets a more expensive one.
The subtle input is the "bill value" of a solar kWh. Under full retail net metering, every kWh you export is worth what you'd have paid — 100%. Under net billing regimes like California's NEM 3.0, exports earn far less than retail, so the blended value of production depends on how much you self-consume. That's what the value slider models, and it's why batteries changed the California calculus — they convert low-value exports into full-value self-consumption.
Realistic modeling also includes 0.5% annual panel degradation and utility rate escalation around 3%; both are built into the 25-year figure above. A payback of 6–10 years against a 25+ year equipment life is the normal shape of a good project.