How it works
This deliberately simple model excludes exports, degradation, maintenance, financing, battery cost, tariffs and incentives. It is not a quotation.
FormulaAnnual savings = solar generation × self-use fraction × electricity price.
HOME & ENERGY / HOME INVESTMENT
← All toolsSolar payback estimator
Estimate annual bill savings and simple payback time for a solar installation.
Your numbers
Loading calculator...
◈ Your values stay in your browser. No account needed.
YOUR RESULT
Enter your numbers to see a result.
Solar payback estimator: a worked example
With installation cost 6,500, estimated annual generation (kwh) 3,500, solar used at home (%) 65, import electricity price / kwh 0.27, the estimated annual savings is $614.25.
| Installation cost | 6,500 |
|---|---|
| Estimated annual generation (kWh) | 3,500 |
| Solar used at home (%) | 65 |
| Import electricity price / kWh | 0.27 |
| Estimated annual savings | $614.25 |
|---|---|
| Simple payback time | 10.58 years |
| Annual solar used at home | 2,275 kWh |
| 10-year simple net savings | -$357.50 |
Amounts are shown in US dollars for illustration. Choose your own currency in the calculator above; it labels amounts and does not convert them.
Make the numbers useful
Try changing one input at a time. The live result helps you see which assumption has the greatest effect.
Use Save scenario A, change an input, and compare both results side-by-side. You can also share your settings using a link.
Modelled results are estimates. Independently check decisions involving health, finances or safety.
Frequently asked questions
How is the solar payback estimator calculated?
Annual savings = solar generation × self-use fraction × electricity price. This deliberately simple model excludes exports, degradation, maintenance, financing, battery cost, tariffs and incentives. It is not a quotation.
What does the solar payback estimator example show?
With installation cost 6,500, estimated annual generation (kwh) 3,500, solar used at home (%) 65, import electricity price / kwh 0.27, the estimated annual savings is $614.25. Simple payback time: 10.58 years; Annual solar used at home: 2,275 kWh; 10-year simple net savings: -$357.50.
What assumptions and limits apply?
This is an estimate based on the inputs and assumptions shown on this page, not professional advice. Check anything with financial, health or safety consequences independently.
Is my data private?
Yes. Calculations run in your browser and your numbers are not sent to a server. A share link contains the inputs you choose to share, so check it before sending it to anyone.
Can I use my own currency?
Yes. Pick from 33 currencies and the amounts are labelled to match. The selector does not convert between currencies, so enter prices in your own currency.