Federal SRES · Solar & battery STCs

Federal solar and battery STC calculator

The Small-scale Renewable Energy Scheme is the federal mechanism behind what most people call the solar rebate. It creates small-scale technology certificates on eligible solar and battery installations, and it winds down to nothing at the end of 2030. From 1 October 2026 the solar cap rises from 100 kW to 1 MW, which brings most commercial roofs inside it for the first time. Enter your system size below to estimate how many certificates a project could create, and what they are worth today.

Applies Australia wide·Commercial scale from 1 October 2026·Estimate only, not a quote
kW
The rated panel capacity, not the inverter size.
kWh
What you can actually cycle, not the nameplate figure.
Zone sets the solar rating. Confirm yours on the regulator’s postcode list.
The certificate count is set by the install date, not the order date.
Not sure what size system to enter? Work it out
Enter a figure above and this suggests a system size.

This is a starting point for the calculator, not a design. It is our estimate rather than part of the scheme method, and the certificate figure below is worked out from whatever size you enter. What your roof and your switchboard actually support is a site question.

 
Certificate price: $34.00
STCs are traded below the $40 clearing house price. Prefilled at $34.00, a deliberately conservative reading of the market.
Indicative certificate value

From small-scale technology certificates, on the system above.

From the solar
From the battery
Get this modelled on your real load

Certificates are traded, so the value moves with them

 

Your project is worth whatever certificates fetch on the day they are created, not what they fetch today.

How your number was built

Worked through on the figures you entered, step by step, so you can check it or hand it to your own engineer.

    The scheme rules behind those steps

    • Solar certificates are deemed: rated capacity in kilowatts, multiplied by the zone rating, multiplied by the years left in the scheme, rounded down to a whole certificate.
    • Zone ratings are 1.622 in zone 1, 1.536 in zone 2, 1.382 in zone 3 and 1.185 in zone 4. The zone is set by postcode, not by state.
    • The scheme ends on 31 December 2030, so the deeming period is whatever is left: 5 years for a 2026 install, 4 for 2027, down to 1 for 2030.
    • From 1 October 2026 the scheme covers solar to 1 MW of rated capacity, up from 100 kW. Larger systems run on the large-scale scheme, creating LGCs on metered output instead.
    • Battery certificates are created on usable capacity at a published rate per kilowatt hour, adjusted by a factor that steps down each year of the scheme.
    • Batteries need at least 5 kWh of usable capacity to qualify, and certificates are created on the first 50 kWh. Installed capacity can run to 100 kWh.
    • The battery must be paired with solar, new or existing, and must be capable of being connected to a virtual power plant even if it never joins one.
    • Equipment has to be on the approved product list and installed by a Clean Energy Council accredited installer, to AS/NZS 5033 for solar and AS/NZS 5139 for storage.
    • The certificate discount is claimed once per installation. Adding capacity later is a separate installation on the rules and the rates that apply then.
    • Certificates are created and traded by a registered agent, usually the installer, and the value shows up as a discount on the invoice rather than a payment to you.

    What we have deliberately left out

    State and territory schemes sit on top of this and are not in the figure above. In New South Wales the Peak Demand Reduction Scheme creates a separate certificate for commercial batteries, which we have built its own calculator for. Whether a federal and a state incentive can both be claimed on one project depends on the state rule, so we check it per project rather than adding the two together here and flattering the number.

    Treat this as a scale check, not an offer, a quote or a ruling on eligibility. It applies the scheme method to the numbers you typed in and nothing else. It has not seen your roof, your load, your switchboard or your product list. Certificates are created by a registered agent at the time of the installation, not by this page, and the price they fetch is set by the market on the day. Whether a project qualifies at all depends on the current scheme rule, the equipment used, the installer’s accreditation and a site assessment.

    What the number doesn’t tell you

    The certificate value is the easy part of the business case

    Your figure above is what the federal scheme is likely to contribute. It does not tell you whether the system is the right one for your site. Three things decide that, and none of them are in the calculator.

    1. 01

      Does your load actually use what the roof makes?

      Certificates are deemed on capacity, so the scheme pays the same whether the generation is consumed on site or exported for a few cents. Your return does not work that way. A site that runs hard through the middle of the day gets most of the value back at the retail rate. A site that empties out at 3pm does not, and the fix is usually storage or a different array size, not a bigger one.

    2. 02

      Was your last design drawn against the old 100 kW rule?

      For years the small-scale scheme stopped at 100 kW, which quietly pushed a lot of projects to be designed at 99. From 1 October 2026 the band runs to 1 MW, so a roof that was cut down to fit the rule can be sized to the load instead. Bigger again is not a problem either: the large-scale route earns certificates on metered output year after year, which can be worth more over the life of the asset. Either way it is a modelling question, not a rule of thumb.

    3. 03

      Who carries it after handover?

      An incentive reduces what the asset costs to buy. It says nothing about who funds the balance, who monitors output so a failed string is caught in a week rather than a quarter, who cleans it, and who is accountable in year seven when yield starts to drift below the model.

    That third one is why Zool Energy is built the way it is. We are an energy partner, not an installer: we design, fund, build and operate the system ourselves, and you pay a fixed cost per kWh under a single agreement for 10 to 25 years. No capital outlay, and fees apply under the agreement. Either way, the modelling comes first.

    Get your site modelled
    No cost, no obligation

    Get it modelled on your actual load

    Send us your details and we will come back with a modelled position for your site: the array your roof and your load actually support, how much of the generation you would use rather than export, whether storage earns its place, and exactly what the federal certificates are worth on that configuration.

    • We will request your interval data for you, with your authority
    • Modelled on your real consumption, not a typical profile
    • Small-scale and large-scale compared, if you are near the 1 MW line
    • Costed both ways: outright purchase, or funded under Total Care
    • If it does not stack up on your site, we will tell you that

    Trouble loading the form? Open it in a new tab. We use your details to respond to this enquiry. Modelling is indicative and based on the information supplied. Any agreement is subject to credit assessment and contract terms.

    Questions

    The federal solar and battery scheme, briefly

    See how we build commercial solar
    What is the SRES?

    The Small-scale Renewable Energy Scheme is the federal scheme that creates small-scale technology certificates, or STCs, for eligible solar, battery and water heating installations. It is the mechanism behind what most people call the solar rebate. It is administered nationally by the Clean Energy Regulator and applies in every state and territory.

    Is the STC discount a rebate?

    Not in the sense of a payment you receive. The system creates certificates with a market value, which are assigned to the installer or an agent in exchange for a discount off the installed price. Nothing arrives in your bank account, and you do not claim anything back at tax time. What changes is the delivered cost of the project.

    How big can a system be and still create STCs?

    From 1 October 2026 the scheme covers solar to 1 MW of rated capacity, up from 100 kW. Larger systems sit in the large-scale scheme and create large-scale generation certificates instead, earned on metered output year by year rather than deemed up front. Bigger is not worse, it is a different mechanism with a different cash flow, and on a large roof it is often the stronger of the two.

    Why does the value fall every year?

    Solar STCs are deemed to the end of the scheme on 31 December 2030. A system installed in 2026 is deemed for five years, one installed in 2027 for four, and so on to a single year in 2030. The federal battery certificates step down on their own published schedule. Both mean the same project is worth measurably less the longer it waits, which the calculator above shows directly.

    What decides the number of STCs a solar system creates?

    Three things: the rated capacity of the panels in kilowatts, the climate zone rating where the site is, and the deeming period remaining in the scheme. Zone ratings run from 1.185 in the cooler south to 1.622 in the far north, so the same array creates materially more certificates in Cairns than in Hobart. The zone is set by postcode, so a site can sit in a different zone to the capital it reports to.

    Do batteries create STCs too?

    Yes, under the federal battery discount that runs through the same scheme. The battery has to be paired with solar, new or existing, and it has to be capable of joining a virtual power plant even if you never enrol it in one. Certificates are created on usable capacity, with a floor at the small end and a cap on how much capacity counts, on a rate that steps down each year.

    Can the federal certificates be combined with a state incentive?

    Sometimes, and it depends on the state scheme and the current rule rather than on anything federal. Some state programs were re-set so the two could sit together, others cannot be claimed alongside. It is worth confirming per project rather than assuming, and it is one of the first things we check when we scope.

    Can it work alongside a funded agreement rather than a capital purchase?

    Yes. Under a funded agreement the certificate value reduces the delivered cost of the system, which flows into the fixed cost per kWh rate rather than arriving as a discount your organisation has to chase itself.

    Is this calculator a quote?

    No. It applies the published scheme methodology to the numbers you entered. It does not assess your roof, your load, your switchboard or your eligibility, and it does not include the cost of the system. Treat it as a scale check, then get the site modelled.