What is the federal STC rebate?
STCs, Small-scale Technology Certificates, are a federal incentive legislated under the Renewable Energy (Electricity) Act 2000. Every accredited solar install earns certificates, and those certificates are tradable on a regulated market. In practice, your installer keeps the STCs in exchange for an upfront discount on your invoice, so you never claim anything; the rebate is baked into the quote.
It is the largest single solar discount available to Australian households, applies in every state and territory, and stacks with state programs like Victoria's $1,400 Solar Homes rebate. The scheme winds down on a fixed schedule: the "deeming period" in the formula drops by one year every 1 January until the rebate reaches zero for 2031 installs.
How the STC rebate is calculated (the honest formula)
STCs = floor(system kW × zone rating × deeming years)
rebate = STCs × STC price
As of July 2026:
- System size: your panel capacity in kW (typical residential: 6.6 kW)
- Zone rating: 1.185 (Melbourne, Hobart) up to 1.622 (Zone 1, remote north-west). Table below.
- Deeming years: 5 for 2026 installs, dropping one year every 1 January until it hits zero in 2031
- STC price: spot price $39.90; the clearing house caps it at $40 ex GST, and installer pass-through is typically $37–$40
- The floor matters: the certificate count is rounded down, never up
For a 6.6 kW system in Sydney (Zone 3, rating 1.382), installed in 2026:
floor(6.6 × 1.382 × 5) = 45 STCs × $39.90 = $1,796 off the invoice
Plenty of pages still quote $2,500 or more for a 6.6 kW system. Those figures come from the old 6-year deeming period, which ended on 31 December 2025. For 2026 installs the deeming period is 5 years, and a 6.6 kW Sydney system creates 45 STCs worth about $1,796 at today's $39.90 certificate price. If a quote or website shows a bigger federal rebate than that, it is running last year's numbers; check the date before you rely on it.
Are solar rebates being cut in 2026? The step-down, year by year
Yes, on a schedule. Every 1 January the deeming period drops by one year, and the rebate falls with it. Here is what a 6.6 kW system in Sydney (Zone 3) gets by install year, at today's $39.90 STC price:
| Install year | Deeming years | STCs (6.6 kW, Zone 3) | Rebate value |
|---|---|---|---|
| 2026Now | 5 | 45 | $1,796 |
| 2027 | 4 | 36 | $1,436 |
| 2028 | 3 | 27 | $1,077 |
| 2029 | 2 | 18 | $718 |
| 2030 | 1 | 9 | $359 |
| 2031 | 0 | 0 | $0 (scheme ended) |
Install a 6.6 kW system in Zone 3 this year and the federal rebate is $1,796; wait until January 2027 and it is $1,436, a permanent loss of $360. On a 10 kW system the gap is $558 ($2,753 this year vs $2,195 next). The rebate is set by the date the system is installed and registered, so December quotes need realistic install lead times.
STC zones: what each city gets in 2026
Australia is split into four STC zones by solar irradiance. Same system, different postcode, different rebate. Computed at the current $39.90 certificate price for 2026 installs:
| Zone | Rating | Example cities | 6.6 kW rebate | 10 kW rebate |
|---|---|---|---|---|
| Zone 1 | 1.622 | Remote NT and far-north WA (no capital cities) | $2,115 | $3,232 |
| Zone 2 | 1.536 | Darwin | $1,995 | $3,032 |
| Zone 3 | 1.382 | Sydney, Brisbane, Adelaide, Perth, Canberra | $1,796 | $2,753 |
| Zone 4 | 1.185 | Melbourne, Hobart | $1,556 | $2,354 |
Zone ratings are set per postcode, so outer-metro and regional addresses can differ from their capital. The rebate calculator resolves your exact postcode.
How many STCs does your system create?
Bigger systems create more certificates, and the count is always rounded down. For 2026 installs in Zone 3 (Sydney, Brisbane, Adelaide, Perth, Canberra) at the current $39.90 price:
| System size | STCs created (Zone 3) | Rebate value |
|---|---|---|
| 5 kW | 34 STCs | $1,357 |
| 6.6 kW | 45 STCs | $1,796 |
| 8 kW | 55 STCs | $2,195 |
| 10 kW | 69 STCs | $2,753 |
| 13.2 kW | 91 STCs | $3,631 |
What is the STC price in 2026?
STCs trade on an open market, so the dollar value of each certificate moves with supply and demand. The spot price is $39.90 (week ending 10 July 2026), just under the $40 ex GST cap set by the Clean Energy Regulator's clearing house. Installer pass-through is typically $37–$40 per certificate. Because the market sits so close to the cap, most installers lock in a fixed STC value when they quote, so the discount you are shown is the discount you get even if the market dips slightly before your system is registered.
How to claim the STC rebate
You don't need to file anything yourself. The process is:
- Choose an accredited installer. (We match you with one for free.)
- Sign the install contract. The STC discount is shown as a line item.
- Installation. Usually completed in a single day.
- Within 1–2 weeks, the installer registers the system with the Clean Energy Regulator and creates the STCs.
- The installer keeps (or sells) the STCs and your invoice reflects the discount already.
That's it. The only paperwork you handle is the install contract itself. If your installer ever asks you to file STC paperwork yourself, that's a red flag: they're either not accredited or trying to charge full price and pocket the rebate.
STC rebate vs. state rebate vs. feed-in tariff
These three get confused all the time. Here's the difference:
| What it is | When you get it | Typical value |
|---|---|---|
| Federal STC rebate | Once, at point of sale (lower invoice) | $1,556–$1,995 on 6.6 kW in the capitals (2026) |
| State rebate (varies) | Once, at point of sale (where applicable) | Up to $1,400 solar (VIC) · battery and VPP incentives elsewhere |
| Feed-in tariff | Ongoing, in cents per kWh exported | $200–$500/yr typical |
Common questions
Are solar rebates being cut in 2026?
Yes, on a legislated schedule rather than by surprise. The federal STC rebate steps down every 1 January as the deeming period drops by one year: 5 years for 2026 installs, 4 in 2027, 3 in 2028, 2 in 2029, 1 in 2030, then zero from 2031. In dollars, a 6.6 kW system in Sydney gets about $1,796 for a 2026 install and about $1,436 from January 2027. The scheme is winding down as planned, not being scrapped early.
How much is the solar rebate on a 6.6 kW system?
For a 2026 install at the current $39.90 certificate price: about $1,556 in Melbourne and Hobart (Zone 4), $1,796 in Sydney, Brisbane, Adelaide, Perth and Canberra (Zone 3), and $1,995 in Darwin (Zone 2). The rebate is applied as a point-of-sale discount on your invoice, not paid to you in cash.
How do I calculate STCs?
STCs = system size (kW) × your zone rating × the deeming years, rounded DOWN to a whole certificate. Example for 6.6 kW in Sydney installed in 2026: 6.6 × 1.382 × 5 = 45.6, floored to 45 STCs. At the $39.90 market price that is about $1,796 off your invoice. Deeming is 5 years for 2026 installs and drops by one year every 1 January.
When does the solar rebate end?
31 December 2030 is the last day a new install earns STCs; from 2031 the rebate is zero. Before then it shrinks every 1 January as the deeming period drops: a 6.6 kW Sydney system gets about $1,796 in 2026, $1,436 in 2027, $1,077 in 2028, $718 in 2029 and $359 in 2030.
Do I claim the STC rebate myself?
No. Your accredited installer creates the STC certificates and either keeps them in exchange for the upfront discount on your invoice, or sells them on the STC market and passes the proceeds to you as a discount. Either way, you never fill in a form; the rebate just lowers your invoice.
Is the STC rebate the same as a solar feed-in tariff?
No, they're different things. The STC rebate is a one-off upfront discount on your system. A feed-in tariff is the ongoing per-kWh credit your retailer pays for solar you export to the grid. You get both, but the STC discount is by far the bigger ticket item, and with feed-in tariffs now at a few cents per kWh in most states, it is the part worth timing correctly.