The federal STC discount is the baseline everywhere in Australia. State and territory programs add to it, sometimes generously and sometimes not at all, and they come and go quickly. So “do STCs stack with state rebates” gets an honest answer of “usually, but check”.
How the layers work
- Federal STC discount. For solar, a certificate count based on size, zone and deeming years. For batteries, the Cheaper Home Batteries Program factor. Applied at the point of sale.
- State or territory rebate. A grant, loan or incentive from the government of where you live. These are separate from STCs.
- Network or retailer incentives. For example VPP sign-up credits.
The federal discount is applied first, and the state benefit then applies to your net price or to a set amount, depending on the scheme.
What is available, at the time of writing
- Victoria. Solar Victoria’s rebate has an income cap that dropped to $150,000 on 1 July 2026. Victorian Energy Upgrades, run by the Essential Services Commission, covers other products. The Victoria Solar Battery Loan has closed.
- NSW. The NSW battery incentive moved into the federal program in 2025, with a PDRS incentive for VPP connection. The PDRS BESS1 activity was suspended from 1 July 2025, and a commercial battery incentive started from 1 September 2026, as reported.
- WA. The residential battery scheme is active and requires VPP participation. See WA’s scheme and the federal rebate.
- ACT. The Sustainable Household Scheme has supported zero-interest loans. See the ACT scheme.
- Closed. NT battery scheme, Tasmania Energy Saver Loan and Queensland Battery Booster.
For dollar amounts and caps, use the official page for each scheme, because they change.
Traps to check
- Eligibility cut-offs such as income, property type or rental status.
- Product lists. State schemes may require products different from the federal approved list.
- Double dipping. A few schemes forbid combining benefits for the same item.
- Installer approval. Some programs require installers to be approved by the scheme.
What this means for you
Start with the federal discount, using the STC calculator or battery calculator, then layer on what your state offers. See VPP battery rebates for the credits tied to VPP. Your homeowners guide is the starting point for the full picture, and installers can see how certificates settle at STC trading and battery STCs.