Solar payback calculator
What a system would generate where you live, what share of it you would actually use, and how long it takes to pay for itself — priced at your own electricity rate rather than a national average.
The part most calculators leave out is the third question, and it is the one that decides the answer.
Your roof and your household
Your bill gives it, usually as a daily average — multiply by 365. Leave it and we estimate from your household size.
The rate the savings are priced at
These are New South Wales’s published reference rates. They are a starting point, not what you necessarily pay — put the numbers from your own bill in and every figure on this site changes with them.
The usage rate on your bill, sometimes called the peak or anytime rate.
Saved in this browser and nowhere else. No account, no email, nothing sent to a server.
Which size, for your household
Each of these is the same roof, the same household and the same day pattern. What changes is how much of the generation has somewhere to go.
What moving load into daylight is worth
This is the part no other Australian solar calculator can do, because it needs to know what your hot water and your pool pump actually cost — and this site has already worked both out for your household.
Nothing here needs new equipment. It is a timer setting.
Tick anything you could move into the middle of the day and this will price it. Nothing here needs new equipment — it is a timer setting.
What your exports are worth
In New South Wales the model prices exported solar at 5.0c per kilowatt hour, against a retail rate of 33.1c for the same unit used at home. Using it is worth 7 times as much as selling it.
Retailer-set: Retailer-set. IPART publishes a non-binding benchmark range of 4.8c to 7.3c for 2026; the model uses the bottom of it.
The benchmark is guidance, not a floor. Retailers are free to pay less and some do.
The federal rebate on this system
A 6.6 kW system in New South Wales creates 45 certificates — 6.6 kW × 1.382 (zone 3) × 5 years of deeming, rounded down — worth about $1,710 at $38 each.
Australian installers almost always quote a price with that already taken off, so it is shown here for information rather than subtracted again. If a quote does not say, ask.
It shrinks every year. The deeming period falls by one year each January and the scheme ends in 2030. The same system installed next year creates 36 certificates, worth $1,368 — $342 less for waiting.
What this does not include
Batteries, which are a separate decision with separate arithmetic. Meter changes, which some retailers charge for. Any state rebate or interest-free loan, because those come and go — the rebate pages track the ones that apply to water heating and heating and cooling, and a solar equivalent is coming.
It also assumes the panels degrade at half a per cent a year and that you keep the system twenty years, and it deliberately does not escalate electricity prices or discount future savings. Both of those adjustments would shorten the payback, which is exactly why they are not here: a payback figure is easier to trust when nobody has had a thumb on the scale.