Installers in Queensland, South Australia, Western Australia, Tasmania, the ACT and the Northern Territory often ask whether a state rebate changes the STC claim on a solar job. It does not. The STC calculation depends on the system’s rated output, the postcode zone and the deeming period, and those are federal.
How the claim is calculated
For small-scale solar the deeming period is 5 years for 2026 installs, 4 for 2027, falling to 1 year in 2030, with the scheme ending on 31 December 2030. Zone ratings are 1.622, 1.536, 1.382 and 1.185. Perth, Brisbane, Adelaide and Canberra are zone 3, Hobart is zone 4, Darwin is zone 2 and Alice Springs is zone 1. Use the STC calculator and see deeming period and zone ratings. If the system is above 100 kW, read mid-scale solar STCs instead.
What states add on top
The state layer is mostly about batteries, loans and VPP incentives rather than a solar panel grant. At the time of writing:
- Queensland: the Battery Booster has closed. See closed battery schemes and our Queensland rebate page.
- South Australia: battery support has changed; see the SA scheme and the SA rebate page.
- Western Australia: the battery scheme is active and VPP-required; see the WA scheme and the WA rebate page.
- Tasmania: the Energy Saver Loan has closed; see the Tasmania rebate page.
- ACT: support has centred on the Sustainable Household Scheme and its loans; see the ACT answer and the ACT rebate page.
- Northern Territory: the battery scheme has closed; see the NT rebate page.
We do not quote state dollar amounts here because they change. Confirm on the relevant government page.
What it means at the quote stage
A state loan or grant affects what the customer pays, not what you claim. Show the STC discount as its own line on the invoice and treat any state benefit as a separate line, with its own paperwork. Our guide on stacking federal and state battery offers covers the battery side.
From the desk: If a state scheme requires its own pre-approval or a particular installer status, confirm that before installation. A job that misses a state pre-condition cannot be fixed after the panels are on the roof, even though the STC claim itself is fine.
What this means for installers
Run every solar job the same way: correct postcode zone, correct deeming period, complete evidence, signed assignment. Handle any state benefit as a parallel track. For the claim itself, see the STC trading pillar, how it works and pricing. New and existing installers can start trading once the job file is complete.