Solar Panel Payback Calculator

Estimate how many years solar panels take to pay for themselves from system cost, incentives, yearly kWh produced and your electricity rate.

$
Total quoted price before incentives. Example rate — enter your own.
Your rate is remembered on this device.
$
Utility or state rebates and tax credits you actually qualify for. The U.S. federal residential clean energy credit is not available for systems placed in service after December 31, 2025.
kWh/yr
From your installer’s proposal or a production estimate such as NREL’s PVWatts.
$per kWh
Example rate — enter your own. Your retail rate for power used on site; if exports are credited at less, use a blended figure.
Your rate is remembered on this device.
%
Assumed yearly rise in your rate. Set to 0 for today’s prices only.
Your rate is remembered on this device.
%
Many panel warranties assume a loss of around 0.5% per year; check yours.
$per year
Cleaning, monitoring and a reserve for inverter replacement.
Your rate is remembered on this device.
years
Panel warranties commonly run 25 years.
Simple payback (today’s prices)
14.7 years
Payback with price changes & panel ageing
13.4 years
Net cost after incentives
$20,000.00
First-year savings
$1,360.00
Total savings over 25 years
$40,834.30
Net benefit over 25 years (savings − net cost)
$20,834.30
Return on net cost over 25 years
104.2 %
Cost per kWh produced over 25 years
$0.11
Net cost ÷ lifetime production (no upkeep, no discounting). Compare with your electricity rate.

Estimate generated with SortedSums: https://sortedsums.com/solar-payback-calculator/. For informational purposes only; verify before relying on it.

Estimate only. This tool is for informational and educational purposes. Results depend on your inputs and simplifying assumptions, and are not a substitute for professional engineering, design or financial advice. Always verify with a qualified professional and applicable codes before purchasing, building or making decisions.

How it’s calculated

Payback is how long the electricity a system saves takes to add up to what it cost after incentives.

Net cost = system cost − incentives Simple payback = net cost ÷ (kWh per year × rate − upkeep) Savings in year y = kWh × (1 − loss%)^(y−1) × rate × (1 + increase%)^(y−1) − upkeep Payback = first year in which cumulative savings ≥ net cost (interpolated)

Example (default example values): $20,000 system, no incentives, 8,000 kWh/yr at $0.17/kWh. First-year savings = 8,000 × 0.17 = $1,360, so simple payback = 20,000 ÷ 1,360 = 14.7 years. With prices rising 2% a year and output falling 0.5% a year, yearly savings grow by about 1.5%, and payback comes at about 13.4 years, and 25 years of savings total about $40,834.

This is a planning estimate, not financial advice. It ignores financing interest, the time value of money, net-metering and export rules, fixed utility charges, insurance, roof work and property-tax effects. Production depends on location, tilt, shading and weather; get an independent production estimate and several written quotes before deciding.

Frequently asked questions

What is a good solar payback period?

It depends on local electricity prices, sunshine and incentives. A payback well inside the panel warranty (often 25 years) leaves years of savings afterwards; a payback close to or beyond it means the system may never come out ahead.

How do I estimate yearly production?

Use the kWh figure in your installer’s proposal, and cross-check it with a free tool such as NREL’s PVWatts, which models output for your address, roof direction and tilt.

Is there still a federal tax credit for home solar?

The IRS residential clean energy credit (30%) applies only to property placed in service by December 31, 2025. Check state and utility programs, which vary widely.

What if I export power to the grid?

If exported kWh earn less than the retail rate, the value of each kWh is lower. Use a blended rate weighted by how much you use on site versus export.

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Sources

Formulas are taken from the free public references above. Results are provided “as is” for informational and educational purposes only. See our disclaimer.

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