Residential Solar Payback Calculator
Estimate how long it will take for a rooftop solar system to pay for itself based on realistic local economics. This calculator focuses on typical U.S. residential systems and explains how panel production, incentives, and electricity savings contribute to the payback timeline.
Why Payback Matters
The payback period indicates when the value of avoided utility costs equals the net cost of the solar installation. Homeowners combining a 6 kW array with a federal tax credit often see a payback of 7 to 12 years in sunny states. Every input below directly influences that timeline, so understanding your own cost per watt, incentives, and local rates will help you project the long-term benefit accurately.
Input Your Project Assumptions
Realistic Example
A homeowner in Phoenix installs a 6.4 kW array at $2.80 per watt. With 6.5 peak sunlight hours per day, a 78% performance ratio, a $0.14/kWh electricity rate (rising 3.5% annually), and a 30% federal tax credit, the system generates roughly 11,850 kWh per year, saving over $1,650 annually. The payback comes in under a decade and the 25-year net benefit approaches $32,000 after accounting for escalating rates.
The calculator mirrors this workflow so you can replace those numbers with your local costs. Review the projected annual production, compare the savings to your current electric bill, and adjust the incentive to see how it shortens or lengthens the payback period.