When federal and state battery incentives are stacked, the federal part is a single, well-defined claim and the state part is a separate process with its own rules. Treat them as two jobs that share one battery. The federal STC claim goes to the Clean Energy Regulator. The state piece goes wherever that scheme says, on its own timeline, and each can succeed or fail independently.
This article is about how to run that in practice, for installers who sell stacked quotes and households who want to understand what they are agreeing to. For the yes-or-no overview, start with can you stack battery rebates.
Two claims, one battery
| Federal STC claim | State scheme | |
|---|---|---|
| Who runs it | Clean Energy Regulator | State agency or scheme administrator |
| Evidence | Assignment form, photos, serials, compliance | Scheme application, often similar documents plus extras |
| Delivered as | Upfront discount via certificates | Discount, certificates, payment or loan, depending on state |
| Timing | Claim lodged after install | Pre-approval, post-install claim, or both |
| Risk | Rejection or delay on evidence | Funding cap, closure, deadline |
The sequencing is what trips people. A state scheme might need registration before installation, while the federal claim is lodged after. If you miss the early step, the later one cannot rescue it.
A sequence that works
- Check what is open. Confirm the status of every scheme you plan to rely on at the time of quoting.
- Quote with the stack itemised. Federal STC value at a conservative price, state value as the scheme states it, any VPP credit separately.
- Register or pre-approve where required before installation.
- Install and capture evidence once, for both. The same photos and serials often serve both claims, but the state scheme may ask for more.
- Lodge the federal claim with a pre-check.
- Lodge the state claim inside its deadline.
- Reconcile the final invoice against what was actually received.
What the state schemes look like
State incentives differ in design, and this is the point that makes stacking hard to describe in one sentence.
- Certificate-based schemes, like the NSW Peak Demand Reduction Scheme, where a battery that connects to a VPP or provides peak demand reduction earns certificates (PRCs) that are traded, similar in spirit to STCs. The earlier NSW battery incentive moved into the federal program in 2025.
- Direct rebates or discounts, such as Western Australia’s residential battery scheme, which has run with a funding cap and eligibility rules for different network areas.
- VPP-linked incentives, like South Australia’s REPS VPP, where the support is tied to connection rather than purchase.
- Closed or wound-up schemes, where the federal program is the main support.
We do not state dollar amounts here because they change; check the scheme’s official page. Battery rebates by state lists what to look for in each state.
Paperwork that bites
The recurring problems are mundane.
- Name and address mismatches between the state application, assignment form and electrical certificate.
- Photos that satisfy the federal rules but not the state’s, or the reverse.
- Capacity quoted differently in each form. Use usable kWh everywhere.
- Install date outside the scheme window.
- No evidence of VPP enrolment where the state incentive needs it.
Who carries the risk
If the installer applies the state incentive as a discount on the invoice, the installer carries the risk that the scheme does not pay. If the customer claims it, the customer carries the risk. Be explicit, in writing, on the quote. Households should be wary of a price that depends on a payment nobody has confirmed.
For installers, the federal part is the one with the most predictable value, and what makes it work is a clean claim and a fast trader. It is also worth checking how long STC payment should take so you know the real cash cost of carrying the federal discount.
Reconciliation: a worked example
An installer sells a 10 kWh battery in a state with a certificate-based incentive for VPP-connected batteries.
| Item | Amount |
|---|---|
| Battery and installation, before incentives | A |
| Federal STC discount, 68 STCs at $38 | about $2,584 |
| State certificate or payment | as the scheme states, confirmed at quote |
| VPP sign-up credit | delivered by the operator, not the installer |
| Net price to customer | A less the first two lines |
The installer collects the federal value from the trader and the state value from the scheme. The VPP credit is between the customer and the operator, so it should not reduce the invoice unless the installer has the money. Putting it on the quote as a separate “customer receives” line keeps the invoice honest.
When a scheme changes mid-job
If the state scheme changes after the quote but before the install, treat it as you would a factor step: have a clause that says the price adjusts to reflect the incentive in force at installation, or that the installer will honour the quoted price. Households should ask which it is. Silence on the point usually means the customer carries the risk.
Keeping records
Keep each scheme’s confirmation emails, reference numbers and dates in the job folder. If a scheme later queries a claim, or a customer asks why an amount was not paid, the paper trail is what resolves it. For the federal side, retain the evidence for as long as the rules require; our note on how STC audits work explains why. A job folder with two clearly labelled sub-folders, one federal and one state, takes a minute to set up and saves hours later.
What to do next
- Write down which schemes apply in the states you work in and review them every month.
- Add an incentives table to your quote and a “what the customer does” column.
- Keep one evidence pack per job.
- See the program overview, the battery STC page, and our submission guide.
If you want a desk that pre-checks the federal claim so your attention stays on the state piece, talk to us.