In short: on 5 August 2026 the federal government announced that Small-scale Technology Certificates (STCs) will extend from the current 100 kW cap up to 1 MW of solar. The change is intended to apply to systems installed from 1 October 2026 and is worth roughly $272 per kilowatt upfront at today’s certificate prices — about $68,000 off a 250 kW system. One big caveat: it is an announcement, not law. The regulations have not been made yet, and some design details that matter for quoting are still open.
What Was Announced
Climate Change and Energy Minister Chris Bowen used a National Press Club address on 5 August 2026 to announce an expansion of the Small-scale Renewable Energy Scheme (SRES). Solar PV systems with a total onsite capacity between 100 kW and 1 MW will be able to create upfront, deemed STCs instead of registering as a power station and earning Large-scale Generation Certificates (LGCs) year by year. The government’s framing is the “missing middle”: Australia has roughly 22 GW of residential rooftop solar and only about 5.6 GW of commercial rooftop, against an estimated 80 GW-plus of commercial roof space that could host panels.
The intended start date is 1 October 2026, applying to systems installed from that date. Both the ministerial release and the Clean Energy Regulator qualify it the same way: “subject to regulations being made.” As of the announcement, no amending regulation exists on the Federal Register, so the 100 kW limit is still the law today. The date can slip if the regulations are not finalised in time.
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What It Is Worth
The government’s own worked examples put the upfront discount at about 20% of installed cost. They also scale exactly linearly, which tells us something useful: the numbers match the existing STC formula (system size × zone rating × deeming years × certificate price) applied unchanged above 100 kW, with no taper and no cap.
| System size | STCs (zone 3, 2026 install) | Upfront value at ~$39.40 | Source |
|---|---|---|---|
| 99 kW | ~684 | ~$27,000 | Available today |
| 250 kW | ~1,727 | ~$68,000 | Minister’s example |
| 500 kW | ~3,455 | ~$136,000 | Minister’s example |
| 850 kW | ~5,873 | ~$232,000 | Minister’s example |
| 1 MW | ~6,910 | ~$272,000 | Our extrapolation |
Zone matters: the deeming calculation uses a postcode zone rating between 1.185 and 1.622, so the same system is worth more in Brisbane than in Hobart. The examples above use zone 3 (1.382), which covers most of the east-coast capitals. Certificate price is the spot STC price, which has sat just under the $40 clearing house cap all year.
For context on why installers care: the 100 kW line is the reason the 99 kW system exists. Thousands of commercial roofs got a system sized to duck under the cap, because crossing it meant losing the upfront rebate, registering as a power station, adding revenue metering, and collecting LGCs one year at a time against a price outlook that weakens toward 2030. From 1 October, a site that needs 300 kW can be quoted as 300 kW.
How the Maths Works Above 100 kW
Nothing announced changes the STC formula itself. Certificates are still deemed generation: system capacity in kW, times the postcode zone rating, times the deeming period in years, rounded down. A 2026 install gets 5 deeming years (2026 through 2030, when the SRES ends).
The open question is what happens to the deeming period for later installs. Under the current rules it steps down every calendar year: a 2027 install gets 4 years, 2028 gets 3, and so on. The Smart Energy Council has stated that mid-scale systems will keep a fixed 5-year deeming rate through to the end of 2030 rather than stepping down. That would be a materially better deal for a 2028 install (5 years instead of 3), but it appears in no government document, and for a 2026 install the two designs give the same answer, so the minister’s examples cannot settle it. Treat the fixed rate as unconfirmed until the regulations publish.
What We Still Do Not Know
- The deeming design for 2027 and beyond, as above. This changes the value of any project that will not be installed this calendar year.
- Panel or inverter capacity. The announcement says “total onsite capacity between 100 kW and 1 MW” without defining the measurement basis. The current sub-100 kW test uses panel (DC) rated capacity, which is the likely continuation, but it is not stated.
- The 250 MWh annual output limit. Today a small generation unit must also produce under 250 MWh a year. An 850 kW system produces around 1,170 MWh, so this limit has to be raised or removed for the new band. No source says which.
- Whether new mid-scale systems can still choose LGCs. Existing accredited systems keep their LGC arrangements. Whether a new 500 kW system installed after 1 October could still elect power-station accreditation instead of STCs is unaddressed.
- Extra compliance requirements. The regulator has flagged that additional design, installation and compliance requirements for mid-scale systems are under consideration. These could affect cost and eligibility at the margins.
What Does Not Change
Systems under 100 kW are untouched; the existing STC arrangements simply continue. Systems above 1 MW stay under the Large-scale Renewable Energy Target and keep earning LGCs. Batteries are not part of this change either way: they sit under the separate Cheaper Home Batteries program, currently 6.8 STCs per usable kWh with its own step-down schedule. And Victorian VEECs keep their own rules under the VEU program. If you want the current state of every scheme in one place, the incentives hub stays updated as the rules move.
The Awkward Eight Weeks
The announcement creates a gap. A 300 kW system installed in September earns LGCs under the current rules; the same system installed in October is intended to earn around $80,000 of upfront STCs. Nothing published so far addresses projects that are mid-pipeline right now, and no transitional rule has been announced for installs between 5 August and 1 October. For projects near commissioning, that difference is now part of the conversation with the customer, and it is worth modelling both pathways before locking a date. The flip side: the 1 October date itself is conditional on regulations being made, so quoting October installs as if the STCs are guaranteed carries its own risk. Quote both, label the assumption.
October Is Half the Story
A month before the STC change, NSW switches on its first commercial battery incentives: PDRS activities BESS4 (business batteries, 20–200 kWh) and BESS5 (C&I batteries up to 30 MWh) start 1 September 2026, worth tens of thousands of dollars on a typical business battery. A commercial site quoted in spring 2026 can stack upfront STCs on the solar with PRCs on the battery, which did not exist as a combination three months ago. We covered the battery side in the NSW battery rebate guide.
How We Are Handling It in Amperage
Amperage already prices incentives off the install date you set on a system, and quotes still apply the 100 kW STC boundary because that is the law until the regulations are registered. The new mid-scale STCs are deliberately not showing yet: the deeming design is unconfirmed, and we would rather your proposals are right than early. Once the regulations are registered, quotes with an install date from 1 October 2026 will pick up the new rules automatically, using whatever the regulations actually specify rather than what has been briefed to industry. In the meantime the STC calculator and LGC calculator show the announced change alongside the current rules, or you can book a demo to see how a 100 kW–1 MW quote will come together.
The Short Version
STCs are set to extend from 100 kW to 1 MW for solar installed from 1 October 2026, worth roughly $272/kW upfront at current prices, with no taper announced. It is policy, not yet regulation, and the deeming treatment for installs after 2026 is genuinely unresolved. Systems already accredited for LGCs stay where they are. If you quote commercial solar, the 99 kW era is probably ending; check the maths on the real system size and keep the announced-versus-law distinction visible on anything a customer signs.