STC calculator: what are the solar and battery rebates worth at your address?
You've got a quote with an STC discount on it and no way to tell if it's right. Type your postcode, the system size and the price per certificate on the quote. The certificate count and the dollar figure appear as you type, and the count should match the quote exactly. Victorian postcodes now; other states as each zone table is verified. Checked 23 September 2026.
off a 6.6 kW system installed in 2026. $37 is a few dollars under the spot price ($39.60 to $39.90 at the last check) to allow for trader fees; change it to the price on your quote. The certificate count should match the quote exactly.
State rebates stack on this figure: every one, by state, on Rebate Index.
Why two quotes for the same roof show different rebates.
- Certificates depend on your postcode zone (rating 1.185 across most of Melbourne, 1.382 in Bendigo) and round down, so a 6.6 kW system creates 39 or 45 of them, never a flat amount.
- Each installer sets its own price per certificate after trader fees, usually a few dollars under the spot price, and some round the total.
- Batteries use their own factor per usable kWh, taper above 14 kWh and step down on 1 January 2027.
How the STC calculator works: certificates = kW × zone rating × years left in the scheme.
Rounded down to a whole certificate, then multiplied by the certificate price. Zone 3 (rating 1.382) covers most of regional Victoria and Melbourne's north and west. Zone 4 (rating 1.185) covers most of Melbourne, Geelong and Gippsland. 2026 installs get 5 years, 2027 installs get 4.
| Incentive | Certificates or factor now | Value now | From 1 January 2027 | Checked |
|---|---|---|---|---|
| Solar STCs, 6.6 kW, Zone 3 postcode (e.g. Bendigo, Ballarat) | 45 certificates | about $1,650 | 36 certificates, about $1,350 | 23 September · cer.gov.au |
| Solar STCs, 6.6 kW, Zone 4 postcode (e.g. most of Melbourne, Geelong) | 39 certificates | about $1,450 | 31 certificates, about $1,150 | 23 September · cer.gov.au |
| Solar STCs, 10 kW, Zone 3 | 69 certificates | about $2,550 | 55 certificates, about $2,050 | 23 September · cer.gov.au |
| Federal battery discount, per usable kWh (first 14 kWh) | factor 6.8 | about $252 | factor 5.7, about $211 | 23 September · cer.gov.au |
| Federal battery discount, 10 kWh battery | factor 6.8 × 10 kWh | about $2,520 | about $2,110 | 23 September · cer.gov.au |
| Federal battery discount, 13.5 kWh battery | factor 6.8 × 13.5 kWh | about $3,400 | about $2,850 | 23 September · cer.gov.au |
Battery rebate calculator: the Cheaper Home Batteries Program discount by size and date.
Usable kWh times the factor times the certificate price. Factor 6.8 until 31 December 2026, 5.7 from 1 January 2027, 5.2 from 1 July 2027, 4.6 from 1 January 2028. The first 14 kWh get the full rate, 14 to 28 kWh get 60% of it, and 28 to 50 kWh get 15%. Eligible batteries are 5 kWh to 100 kWh usable, with certificates on the first 50 kWh.
off a 10 kWh usable battery installed in 2026, before the installer's certificate fee. Full rate on the first 14 kWh, 60% from 14 to 28 kWh, 15% from 28 to 50 kWh. It needs an approved battery of 5 kWh or more and an approved installer, and sits alongside solar.
Every battery size, with the 2027 step-downs: battery rebate calculator. What a certificate is worth this week: STC price today.
Three steps to check a quote.
- Run the STC calculator. Postcode, system size and the price per certificate on your quote. The certificate count and the dollar figure appear as you type.
- Ask for the count. Every quote can show the certificate count and the price per certificate. The count should match this page exactly for your postcode and size.
- Match it or ask why. If the count matches, the discount is right. If it doesn't, ask the installer why before you sign, or ask us by email. Then check the state rebates that stack on top and the eligibility rules for your situation.
Which upgrade are you looking at?
Pick one, answer four short questions, and the next page shows the published figures for your postcode, what waiting costs on your bill, and the checks to run on any quote. No email, no phone number.
No email, no phone number. The figures appear on the next page, and the only thing we ask after that is whether you'd like to call.
If you sign without checking
Without the count you're trusting a dollar figure nobody can check.
If you check first
With the count, the discount on your quote is arithmetic you've done yourself.
Questions people ask.
What is the current value of STC certificates?
The spot price was $39.60 to $39.90 a certificate at the last check. Installers pass on a few dollars less after trader fees, which is why the STC calculator defaults to $37 and lets you type the price on your quote instead.
How much does the battery rebate drop on 1 January 2027?
The factor goes from 6.8 to 5.7 certificates per usable kWh. At $37 a certificate that is about $252 to about $211 a kWh, so a 10 kWh battery drops from about $2,520 to about $2,110. It steps down again to 5.2 on 1 July 2027 and 4.6 on 1 January 2028.
Why does my quote show a different STC amount from this calculator?
Each installer sets its own certificate price after fees, usually a few dollars under the spot price, and some round the total. The certificate count shouldn't differ: it depends only on your postcode zone, the system size and the install year. Ask for the count and the price per certificate on the quote and compare the count with this page.
How is the solar rebate calculated?
System size in kW, multiplied by your postcode's zone rating, multiplied by the years left in the scheme (5 for a 2026 install, 4 for 2027), rounded down to a whole certificate, then multiplied by the certificate price. At $37 a certificate a 6.6 kW system in Zone 4 comes to about $1,450.
How much is the battery rebate on a 13.5 kWh battery?
About $3,400 for an install before 31 December 2026, and about $2,850 from 1 January 2027, at $37 a certificate. The battery must be on the Clean Energy Council approved list and installed by an accredited installer.
Is this a government website?
No. It's an independent reference published by Timeless Energy Pty Ltd. It doesn't administer any rebate and doesn't decide eligibility. Every figure links to the government body that does.
How current are the figures?
Every figure carries the date it was last checked against the source. The current check date is 23 September 2026. When a program changes, the figure, the date and the note change together.
Why does every amount say 'up to'?
Because that's how the programs work. The published figure is a maximum. What you receive depends on your system size, postcode zone, install date and eligibility, and the installer's paperwork.
How does the site make money?
If you ask a question or request a call, we may refer you to a partner business that can quote the work, and that partner may pay a referral fee. The figures on the site don't change based on who you're referred to.
What this site is, and isn't.
Who publishes it
Timeless Energy Pty Ltd (ABN 22 647 048 520), Suite 101, 68-72 York Street, South Melbourne VIC 3205. Contact hello@rebateindex.com.au.
What it isn't
A government website, a rebate administrator, or an installer. We don't decide eligibility and we can't promise any amount.
How figures are checked
Each figure is read from the body that runs the program (the Clean Energy Regulator, Solar Victoria, the Essential Services Commission and their equivalents in each state) and stamped with the check date. When a source changes, the figure and the date change together.
How we make money
Rebate Calculator is a referral service. If you send your details through the check or ask a question, we match you with accredited installer partners who can quote the work, and we may receive compensation from them. The figures on this site don't depend on it.