Guide, checked 5 November 2026
The next step-downs worked out from the regulator's tables, then a log of rule and scheme changes, newest first, each with its date and source.
Panel STCs fall by a year of deeming every 1 January, and battery STCs step down every six months. The table counts a 6.6 kW system and a 13.5 kWh battery, and the figures follow the date this page was last built.
| Date | What changes | Effect on a job |
|---|---|---|
| Mid to late November 2026 | The regulator expects mid-scale solar STC applications to open | A system of 100 kW to 1 MW installed from 1 October 2026 can apply once applications open |
| 1 January 2027 | Panel deeming period falls from 5 to 4 years Battery STC factor falls from 6.8 to 5.7 | 6.6 kW system: 9 fewer STCs in zone 3 (Sydney, Brisbane, Perth, Adelaide), 8 fewer in zone 4 (Melbourne, Hobart) 13.5 kWh battery: 15 fewer STCs, from 91 to 76 |
| 30 June 2027 | Victoria: current Solar Homes arrangements stay until this date, then solar support moves into the Victorian Energy Upgrades program from 1 July 2027 | Check Solar Victoria for how the new arrangements work as they are published |
| 1 July 2027 | Battery STC factor falls from 5.7 to 5.2 | 13.5 kWh battery: 6 fewer STCs, from 76 to 70 |
| 1 January 2028 | Panel deeming period falls from 4 to 3 years Battery STC factor falls from 5.2 to 4.6 | 6.6 kW system: 9 fewer STCs in zone 3 (Sydney, Brisbane, Perth, Adelaide), 8 fewer in zone 4 (Melbourne, Hobart) 13.5 kWh battery: 8 fewer STCs, from 70 to 62 |
Step-down figures use the tables on the deeming period and battery STCs pages, which follow the regulator's tables. The install date decides which row applies to panels, and the date a battery is certified for compliance decides which applies to a battery.
Changes to the STC rules and the schemes around them, newest first. Each entry was read from the page linked under it. This is not our price or offer: that is on STC price, with its date.
Solar Victoria says the Victorian Government announced on 17 October that support for households to install solar PV will transition into the Victorian Energy Upgrades program from 1 July 2027. Current program arrangements, including rebates with the option of an interest-free loan, stay in place until 30 June 2027.
Our guide: Selling STCs in Victoria
The Clean Energy Regulator says the expanded eligibility applies to eligible systems installed from 1 October 2026. Applications are expected to open in mid to late November 2026, and a system installed on or after 1 October can apply once they do.
Source: Clean Energy Regulator: Changes to mid-scale solar apply from today (1 October 2026); Clean Energy Regulator: Mid-scale solar (updated 7 October 2026)
Our guide: Mid-scale solar STCs
The Clean Energy Regulator reported that the regulations had been amended to expand eligibility for solar PV under the Small-scale Renewable Energy Scheme from 100 kW to 1 MW, for systems installed from 1 October 2026. Eligible mid-scale systems get a fixed five-year deeming period.
Source: Clean Energy Regulator: Mid-scale solar is now legislated (17 September 2026); Clean Energy Regulator: Mid-scale solar (updated 7 October 2026)
Our guide: Mid-scale solar STCs
The Clean Energy Regulator's June quarter 2026 report says the clearing house surplus peaked at 14.4 million STCs in May, with average waits of more than 4 weeks. By the end of the quarter the surplus was 2.5 million STCs and the average wait was 13 days.
Our guide: The STC clearing house
On 5 August 2026 the Australian Government announced that solar PV systems with a total onsite capacity between 100 kW and 1 MW will be eligible to create STCs, where before they could only create large-scale generation certificates. It intended the change to apply to systems installed from 1 October 2026.
Source: Clean Energy Regulator: Expansion of solar PV eligibility under the SRES (August 2026)
Our guide: Mid-scale solar STCs
NSW gazetted updates to the scheme on 1 July 2026, adding battery incentives for apartment buildings and businesses and changing eligibility and onboarding for its virtual power plant incentive. IPART's August 2026 fact sheet says the scheme's incentive for batteries is only available through approved programs, such as an Exempt Energy Program, or at eligible sites such as NSW and local government sites.
Source: NSW Government: Peak Demand Reduction Scheme (updated 12 October 2026); IPART: Thinking of getting a battery? BESS1 fact sheet, version 2.1 (August 2026)
Our guide: Selling STCs in New South Wales
For batteries certified for compliance from 1 May 2026 the STC factor is 6.8 per kWh of usable capacity, down from 8.4 for January to April. Capacity from 14 to 28 kWh counts at 60% of the factor and from 28 to 50 kWh at 15%, and the factor steps down every six months to 2030.
Source: Clean Energy Regulator: Calculate STC entitlements (updated 29 October 2026); DCCEEW: STCs for batteries, and government purchases (updated 9 July 2026)
Our guide: Battery STCs
Each entry is also in an RSS feed, so a feed reader can tell you when a new change is added. We add an entry when the regulator, the department or a state agency publishes a change to the STC rules or the schemes around them.
Checked on 5 November 2026. Rules and market prices change. General information only, not tax, legal or financial advice: check your own position with your accountant.
FAQ
1 January 2027: Panel deeming period falls from 5 to 4 years; Battery STC factor falls from 6.8 to 5.7. 6.6 kW system: 9 fewer STCs in zone 3 (Sydney, Brisbane, Perth, Adelaide), 8 fewer in zone 4 (Melbourne, Hobart). 13.5 kWh battery: 15 fewer STCs, from 91 to 76.
For panels, yes: the regulator sets the deeming period by installation year. For batteries, the regulations set the factor by the date the battery is certified for compliance, which the DCCEEW puts as the date it is installed and certified, so a battery installed in late December and certified in January gets January's factor. Check the guides linked in the log for the details.
Changes to the STC rules and the schemes around them, each with its date and a link to the page it came from. It does not cover our own price or offer: that is on the STC price page, with its date.
The $40 price, the transfer list, the surplus, and when selling there makes sense.
Why panel STCs fall every January, by how much, and what a year's delay costs on a job.
Factors by install date, the taper, and the paperwork that holds up claims.
The 2026 expansion of the scheme: who is eligible, the fixed five-year deeming period, and when claims open.
There is no cost, lock-in or minimum, and you can keep your current trader.