Solar Panel Payback Period
Calculate the payback period, annual savings, and 25-year ROI for a rooftop solar installation after tax credits.
Results
What is it?
The solar payback period is the time it takes for your electricity savings to recover the net cost of your solar installation (after tax credits and rebates). After payback, the system generates essentially free electricity. Most residential solar systems pay back in 6-12 years and have a 25-year warranty life.
How to use
1. Enter the total installed system cost before incentives. 2. Enter the federal ITC percentage (30% through 2032 for US homeowners). 3. Add any state or local rebates in USD. 4. Enter system size in kW and your location peak sun hours (find via NREL PVWatts). 5. Enter your current electricity rate. 6. Review payback period, annual savings, and long-term ROI.
Example scenario
A 7 kW system costs $15,000. With the 30% federal ITC: incentive = $4,500, net cost = $10,500. At 5 peak sun hours, annual generation = 7 x 5 x 365 = 12,775 kWh. At $0.15/kWh, annual savings = $1,916. Payback = $10,500 / $1,916 = 5.5 years. 25-year net savings = $1,916 x 25 - $10,500 = $37,400.
Pro tip
Electricity rates have historically risen 2-3% annually. This calculator uses a flat rate, which understates long-term savings. Adding a battery (e.g., Tesla Powerwall at $10,000-$12,000) typically extends payback by 3-5 years but provides backup power and time-of-use arbitrage benefits. Always get multiple installer quotes — prices vary by 20-30%.