Most weeks the Clean Energy Regulator (CER) says nothing that changes how an installer gets paid. A handful of times a year it does, and the installers who read the notice the week it lands are the ones who do not spend a quarter fixing rejected claims. This is a working summary of the 2026 announcements that touch STC creation and trading, written at the start of October, with what each one means in practice.
We have kept this to what is published and verifiable. Where a detail can still move, we say “at the time of writing” and point to the CER page you should check before you act.
Nothing here replaces the regulator’s own notices. Treat it as the map, and the CER as the territory.
The 2026 small-scale technology percentage
Each year the CER sets the Small-scale Technology Percentage (STP), the share of their electricity that liable entities (mainly retailers) must cover with STCs. For 2026 it is 11.67%. The CER’s projections behind that number used the consultants’ high scenario, specifically to allow for extra certificates from home batteries under the Cheaper Home Batteries Program, and the percentage is consistent with roughly 3.4 GW of rooftop solar.
Why you care: the percentage is demand. A higher STP means retailers must buy more certificates, which supports the price. It is the main reason the spot market has held roughly $38 to $40 against a $40 clearing house ceiling through 2026. Our explainer on the clearing house and the spot price shows how the ceiling and the percentage work together.
Battery evidence and photo rules
From 1 March 2026 the CER tightened the evidence required for battery claims under the Cheaper Home Batteries Program. Photos, serial numbers and installer attestations are checked more closely, and a claim with a weak photo set is now more likely to sit in a queue than clear on the first pass.
This is the announcement most likely to cost a working installer money. A 14 kWh battery at the current factor of 6.8 creates about 95 STCs. At roughly $38.50 that is around $3,660 of certificates waiting on a photo someone forgot to take. The battery submission guide and the CER battery photo guide cover what to capture on the day.
The 1 May 2026 tier change
Since 1 May 2026 the first 14 kWh of usable capacity earns STCs at 100% of the factor, 14 to 28 kWh at 60%, and 28 to 50 kWh at 15%. This is a program rule change rather than a CER ruling, but the CER is the body that applies it to your claim.
| Battery size | Calculation at factor 6.8 | STCs created |
|---|---|---|
| 10 kWh | 10 x 6.8 | 68 |
| 14 kWh | 14 x 6.8 | 95 |
| 20 kWh | 95.2 + (6 x 6.8 x 0.6) | 119 |
| 28 kWh | 95.2 + (14 x 6.8 x 0.6) | 152 |
The jump from 14 to 28 kWh doubles the battery but adds about 60% to the certificates. Customers asking for the biggest battery on the roof should hear that before they sign. See the tier breakdown for the full schedule.
Mid-scale solar moves into the SRES
This is the biggest structural announcement of the year. Systems above 100 kW and up to 1 MW installed from 1 October 2026 now create STCs, with a fixed five-year deeming period, instead of being limited to LGCs. The Renewable Energy (Electricity) Regulations were amended in 2026, and the CER has said applications open in mid to late November 2026. Systems at or below 100 kW are unchanged, and anything above 1 MW stays in the LGC world.
For a commercial installer the arithmetic changes. A 200 kW system in a zone 3 postcode (Sydney, Brisbane, Perth) gives 200 x 1.382 x 5 = 1,382 STCs. At roughly $38.50 that is about $53,200 up front, rather than a stream of LGCs trading at a few dollars each through the year (LGCs have been roughly $6 to $9 in September 2026, after a low near $4 in February). We cover the detail on mid-scale solar and STCs, and the older argument in LGC versus STC.
Projections, the Quarterly Carbon Market Report and the 2030 horizon
Twice a year the CER publishes consultants’ STC projections, and each quarter it publishes the Quarterly Carbon Market Report with creation volumes, registry data and price commentary. These are not headlines, but they are the best free evidence of where supply is heading. The January 2026 projections, for example, were the base for the 11.67% figure.
The scheme itself still ends on 31 December 2030, with the deeming period stepping from five years in 2026 to four in 2027 and one in 2030. Our piece on the deeming change in January 2027 walks through what that does to a standard job.
From the desk: Put the CER’s installer notices page in a monthly calendar reminder, and put the Quarterly Carbon Market Report in a quarterly one. Ten minutes each. Every evidence-rule change we have seen has been signalled weeks before it bit, and the installers who got caught were not caught by surprise, they were caught by not looking.
What the regulator does not do
The CER does not set the STC price, and it does not tell you which trader to use. It sets the percentage, runs the registry, audits claims and publishes data. It does take compliance seriously: claims are checked, installers can be audited, and certificates can be invalidated after the fact. If you want to know how that looks from the inside, read how STC audits work. A notice that begins “the Regulator has identified” is worth reading to the end, because it usually describes a pattern someone else already paid for.
How to read an announcement quickly
Ask four questions of any CER notice:
- Does it change what I must capture on site, such as photos, serials or forms?
- Does it change how many certificates a job creates?
- Does it change who can claim, for example accreditation or eligible equipment?
- Does it start on a date that affects jobs I have already quoted?
If the answer to the first or fourth is yes, brief your crew that week. If the second, re-run your quotes in the STC calculator or the battery STC calculator. If the third, check with your accreditation body before the date, not after.
What to do next
- Read the CER’s own pages for the 2026 STP and the battery program, and note the date you read them
- Re-quote any pending battery or commercial solar job against the tier and mid-scale rules above
- Check how your trader handles evidence problems, using the certificate trader checklist
- See today’s published rate on the pricing page, and read about how STC trading works
For the wider run of dated changes, the scheme changes hub keeps the list in one place.