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Solar Panel Payback Calculator

Estimate how many years until a solar panel system pays for itself. Enter your system size, installed cost, local sun, and electricity rate to see year-one production, annual savings, lifetime savings, and your cost per watt — generic, evergreen math with no perishable incentive assumptions.

kW
$
h
%
$/kWh
yr
Know your panel count & wattage?
W
= 7.2 kW

Payback period

11.9 yr

Lifetime savings (25 yr): $19,896
Annual production
9,198 kWh
Annual savings
$1,516/yr
Cost per watt
$2.57/W
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Payback = installed cost ÷ the yearly value of the electricity it offsets. Enter the cost net of any rebate you qualify for — we don't model incentives, which change. Results depend on your sun, rate, and cost; panels typically last ~25–30 years.

Frequently asked questions

Payback is the installed cost divided by the yearly value of the electricity the system offsets. Annual production is your system size (kW) times daily peak sun hours times 365, reduced by a real-world derate (~80%) for inverter, wiring, soiling, and temperature losses. Multiply that yearly kWh by your electricity rate to get annual savings, then divide the cost by that figure.

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Sources & standards

This tool's methodology and data follow US standards and authoritative public datasets: