EcoTrack

Solar Payback Period Calculator

When does solar start saving you money?

System cost ($)

Annual generation (kWh)

Electricity price ($/kWh)

Payback period

12.5 years

Annual savings: 1,200 $

What you entered

System cost ($): 15000Annual generation (kWh): 8000Electricity price ($/kWh): 0.15

1
Annual savings = kWh × price per kWh
8000 × 0.15= 1200
2
Payback period = system cost ÷ annual savings
15000 ÷ 1200= 12.5 years

Result

Payback period: 12.5 years

This solar system pays for itself in about 12.5 years.

Solar payback period by system cost and electricity price

Payback is system cost divided by annual savings, where savings are the generated kilowatt-hours times the price you would otherwise pay.

System cost	Annual output	Electricity price	Annual saving	Payback
$15,000	10,000 kWh	$0.10/kWh	$1,000.00	15.00 years
$15,000	10,000 kWh	$0.15/kWh	$1,500.00	10.00 years
$15,000	10,000 kWh	$0.25/kWh	$2,500.00	6.00 years
$20,000	12,000 kWh	$0.15/kWh	$1,800.00	11.11 years
$10,000	8,000 kWh	$0.20/kWh	$1,600.00	6.25 years
$25,000	14,000 kWh	$0.30/kWh	$4,200.00	5.95 years

Electricity price matters more than system cost: the same $15,000 system pays back in 6 years at $0.25/kWh and 15 years at $0.10. This is a simple payback and ignores subsidies, panel degradation of roughly 0.5% a year, and future price rises.

Cost divided by yearly savings

Payback period is simply the system's total cost divided by how much money it saves each year on electricity bills — a straightforward way to compare solar against its upfront investment.

What this simple version leaves out

This calculation ignores financing costs, panel degradation over time, changing electricity prices, and available tax incentives or rebates — all of which shift the real-world payback period, usually favorably.

Frequently asked questions

My solar system costs $18,000 and saves $2,400 per year on electricity — when does it pay for itself?

Payback period = $18,000 / $2,400 = 7.5 years. After that, the electricity savings are essentially free for the remaining 17+ years of panel life.

How does solar payback compare to the wind turbine power calculator?

Solar payback focuses on the financial break-even of rooftop panels. The wind turbine calculator estimates power output from wind speed and rotor size. Both help evaluate renewable energy investments, but they answer different questions — money vs. watts.

Do tax credits change the payback period?

Significantly. The US federal solar tax credit (30% as of 2024) would reduce an $18,000 system to $12,600 effective cost, cutting payback from 7.5 to 5.25 years. This calculator uses pre-incentive cost — subtract credits manually for a more accurate estimate.

How long do solar panels last?

Most panels are warranted for 25 years and continue producing at 80-85% capacity after that. With a typical payback of 6-9 years, the remaining 16-19 years are net positive return.