Solar Rebate Calculator Australia
Estimate how Australia’s solar rebate works, why your discount changes by postcode and installation year, and what to check before comparing solar quotes.
Estimate my solar rebateHow does the solar rebate work in Australia?
Australia’s main rooftop solar incentive is the Small-scale Renewable Energy Scheme. It reduces the upfront cost of eligible rooftop solar systems through small-scale technology certificates, often called STCs.
In most cases, homeowners do not claim and sell these certificates themselves. Instead, the installer or retailer applies the STC value as an upfront discount in the solar quote.
Energy.gov.au explains that the Small-scale Renewable Energy Scheme reduces the cost of most new residential and business rooftop solar systems, and the Clean Energy Regulator says households may be able to receive an upfront discount on eligible rooftop solar systems.
This page is general guidance only. STC values, eligibility, state programs and quote discounts can change, so always check current government information and your installer’s quote.
Solar rebate calculation formula
The number of STCs created by a solar system depends mainly on the system size, installation year and postcode zone rating.
The Clean Energy Regulator says the deeming period estimates how many years a system will generate renewable energy and decreases by one year each year until the scheme ends in 2030.
STC deeming period by year
The rebate reduces over time because the deeming period falls each year. That means the same system can create fewer certificates if it is installed later.
| Installation year | Deeming period | What it means |
|---|---|---|
| 2026 | 5 years | Highest remaining deeming period in this table |
| 2027 | 4 years | Fewer STCs than the same system installed in 2026 |
| 2028 | 3 years | The discount continues to reduce |
| 2029 | 2 years | Only two deemed years remain |
| 2030 | 1 year | Final year of the scheme |
Why the same system gets a smaller rebate later
Because the deeming period decreases each year, the number of STCs a new system can create also falls over time.
Estimated STCs for a 6.6kW system in Zone 3
This example uses a 6.6kW system and Zone 3 rating of 1.382.
Calculation: 6.6kW × Zone 3 rating × deeming period, rounded down.
Estimated 2026 STCs for a 6.6kW system by zone
The same system can create different STC counts depending on postcode zone.
Calculation: 6.6kW × 2026 deeming period × postcode zone rating, rounded down.
What affects your solar rebate?
- System size: larger systems can usually create more STCs, up to scheme limits.
- Installation year: later years have a shorter deeming period.
- Postcode zone: sunnier zones generally have higher zone ratings.
- Eligibility: systems must meet scheme requirements.
- STC market value: the dollar value can fluctuate.
- Installer quote method: most quotes show the STC value as an upfront discount.
Why postcode matters
Australia is split into solar postcode zones for STC calculations. A system in a higher-rated solar zone can create more certificates than the same-sized system in a lower-rated zone.
This does not mean one state is always better than another for solar. Your actual savings also depend on your electricity usage, electricity rates, feed-in tariff, roof space and system design.
Is the rebate paid to me?
Usually, no. For many residential installs, the homeowner assigns the STCs to the installer, retailer or registered agent, and the value is applied as a discount on the quoted system price.
This is why your solar quote may show a gross system price, an STC deduction and a final out-of-pocket amount.
Do state rebates also apply?
Sometimes. Separate state or territory programs may offer rebates, loans or battery support, but they vary by location and eligibility.
Energy.gov.au says government subsidies, rebates and loan options may help with rooftop solar or associated batteries, so it is worth checking current programs before accepting a quote.
Example rebate calculation
Here is a simplified example for a 6.6kW solar system installed in 2026 in Zone 3.
| Calculation step | Value |
|---|---|
| System size | 6.6kW |
| Postcode zone rating | 1.382 |
| 2026 deeming period | 5 years |
| Estimated STCs | 6.6 × 1.382 × 5 = 45.606, rounded down to 45 STCs |
This estimates the certificate count, not the final dollar rebate. The final discount depends on the STC value used in your quote.
Solar rebate vs solar savings
The solar rebate helps reduce the upfront cost of an eligible system. Solar savings are different. Savings come from using your own solar electricity instead of buying as much electricity from the grid.
A larger rebate does not automatically mean the best financial outcome. A well-sized system that matches your electricity usage may perform better than a larger system that exports too much electricity at a low feed-in tariff.
Estimate your solar rebate and savings
Use our free solar calculator to estimate your system size, upfront cost, rebate, yearly savings and payback period based on your address and electricity bill.
Solar rebate FAQs
Is there still a solar rebate in Australia?
Yes. Australia’s Small-scale Renewable Energy Scheme still helps reduce the upfront cost of eligible rooftop solar systems, but the available certificate entitlement reduces as the scheme approaches 2030.
What are STCs?
STCs are small-scale technology certificates. Eligible systems can create certificates based on factors such as system size, postcode zone and installation year.
Why does the rebate reduce each year?
The deeming period decreases by one year each year until the scheme ends in 2030. A shorter deeming period means fewer certificates can be created for the same system.
Does every solar system get the same rebate?
No. The rebate can vary by system size, postcode zone, installation year, equipment eligibility and the STC value applied by the installer or agent.
Can I claim the rebate myself?
In many residential quotes, the STCs are assigned to the installer, retailer or registered agent in exchange for an upfront discount. Ask your installer how the STC value is being applied.
Do batteries get rebates too?
Some battery support may be available through federal, state or territory programs, depending on eligibility and timing. Check current government sources before relying on a battery rebate estimate.
Sources and further reading
For official information about solar rebates, STCs and consumer guidance in Australia, visit: