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Solar payback calculator

Return on a rooftop system.

Built and reviewed by Dovanic, Founder and editor, FreeByteLast reviewed: 2026-08-18
$
$
60%
$

Payback

15.9 yr

Yearly benefit

$596

With these inputs, payback comes to 15.9 yr. Yearly benefit works out to $596. The result assumes kwh generated per year stays at 4200%.

25-year value
$14,910
Net gain
$5,410

What moves the number · Payback

Input−10%Now+10%
System cost14.3 yr15.9 yr17.5 yr
kWh generated per year17.7 yr15.9 yr14.5 yr
Rate per kWh17.3 yr15.9 yr14.7 yr
Used at home16.8 yr15.9 yr15.2 yr
Export rate per kWh16.2 yr15.9 yr15.6 yr

Solve for an input

Whatmakesequal

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Return on a rooftop system.

A worked example

Starting figures

System cost
$9,500
kWh generated per year
4,200
Rate per kWh
$0.19
Used at home
60%
Export rate per kWh
$0.07

What it returns

Payback
15.9 yr
Yearly benefit
$596
25-year value
$14,910
Net gain
$5,410

How to read the results

With the defaults above, payback works out at 15.9 yr.

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