Solar Payback Calculator 4kW – Break-Even Period
Estimate solar payback for a 4 kW system at 5.0 peak-sun hours and $0.17/kWh, with the federal tax credit and net metering. Runs in your browser.
Runs locally in your browser — no upload, no trackingTry: System size=4, Peak sun hours=5, Performance ratio (0–1)=0.85, Electricity rate=0.17, Installed cost=2.8, Federal ITC=30, State incentive=0, Annual elec. price rise=0.03, Net metering credit (0–1)=0.85 → 6,205 kWh/yr, $897/yr, $7,840, 8.7 years, $32,690
How to use
A 4 kW system is a common size for a small home. This page pre-fills 4 kW at the U.S. average of 5.0 peak-sun hours and $0.17/kWh; change any value for your own utility and state. Press Calculate to see generation, savings, net cost and payback.
Bigger systems cost more up front but lock in more of your electricity at today's rate. Compare this page with your state's page (linked below) to see how local sun and rates move the break-even year.
FAQ
How long is the payback on a 4 kW solar system?
At the national average (5.0 peak-sun hours, $0.17/kWh, 30% federal ITC) a 4 kW system produces roughly 6,205 kWh a year. Enter your real numbers above for the exact payback period, which is usually in the 6–10 year range.