Construction & Home
Solar Panel Savings Calculator
Estimate annual kWh production, lifetime savings, and payback period for a residential solar array. Customize by state sun hours and utility rate.
kW
¢/kWh
$
%
30% federal through 2032
Annual production
12,755 kWh
Annual savings
$2,296
Payback
7.3 yr
25-yr net
$40,596
Net savings curve
Cumulative savings minus install cost
How this is calculated
Annual production estimate uses the NREL PVWatts methodology:
annual kWh = system kW × peak sun-hours × 365 × 0.78
The 0.78 derate accounts for inverter losses, soiling, wiring, and shading. Sun-hour averages by US state come from the NREL TMY3 dataset.
Federal tax credit
The 30% Residential Clean Energy Credit applies through 2032 (Inflation Reduction Act). It reduces your installed cost dollar-for-dollar before the payback calculation.
Reality check
This is a planning-grade estimate. Quotes from local installers will vary based on roof angle, shading, panel efficiency, and net-metering policy in your state.
Frequently asked
- 6–10 years in most US states with current panel prices and the 30% federal tax credit. Higher utility rates and more sun hours move it under 6.