The STC Rebate Explained: How It Cuts Your Solar Price in 2026

The STC rebate is the federal discount sitting inside almost every Australian solar quote — typically $1,500–$2,000 off a 6.6 kW system in 2026. It's applied automatically as a point-of-sale discount, you never handle any paperwork, and it gets a little smaller every year until the scheme ends in 2030. Here's how it actually works.

What STCs actually are

STC stands for Small-scale Technology Certificate, created under the federal Small-scale Renewable Energy Scheme (SRES) administered by the Clean Energy Regulator. One STC represents one megawatt-hour of renewable electricity your system is deemed to generate. Energy retailers are legally required to buy a set number of STCs each year — that guaranteed demand is what gives the certificates a dollar value, and installers pass that value to you as an upfront discount.

How many STCs your system earns: the formula

Your system's STCs are calculated with a simple formula:

STCs = system size (kW) × zone rating × deeming years

Australia is divided into four solar zones based on sunshine levels, each with a published rating. For a 6.6 kW system installed in 2026 (5 deeming years remaining to 2030):

ZoneWhereZone ratingSTCs (6.6 kW, 2026)Approx. discount*
Zone 1Darwin, far north1.622~53~$2,010
Zone 2Brisbane, Perth1.536~50~$1,900
Zone 3Sydney, Melbourne, Adelaide1.382~45~$1,710
Zone 4Hobart, Canberra1.185~39~$1,480

*At a typical certificate price of around $38 — STCs trade on an open market and usually sit somewhere between $35 and $40. Certificates are always whole numbers (rounded down).

How the discount reaches you: point of sale

You never see, hold or sell a certificate. In practice:

The phase-down: why waiting costs money

The "deeming years" in the formula count down to the scheme's end in 2030. A system installed in 2026 gets 5 years of deemed generation; from 1 January 2027 it's 4, then 3, and so on until the scheme winds up. The same panels in the same suburb earn fewer certificates — and a smaller discount — with every passing year. There is no application deadline to game here: the phase-down is automatic, and waiting never makes the rebate bigger.

Eligibility checklist

To claim STCs, your installation must tick every box:

STCs and the battery rebate are separate — and they stack

The Cheaper Home Batteries Program uses the same STC mechanism but is a separate incentive: since 1 May 2026 it pays a factor of 6.8 STCs per kWh of usable battery capacity (roughly $245/kWh at typical certificate prices), tiered above 14 kWh. Installing solar and a battery together means both discounts apply to the one project — the solar STCs on the panels, the battery STCs on the storage. Our NSW battery rebate guide works through the battery side with a full example.

The bottom line

The STC rebate is real, automatic money — around $1,700 off a typical 6.6 kW system in Sydney or Melbourne this year — but it's on a published glide path to zero by 2030. Check it's itemised on your quote, check your installer is accredited, and don't let anyone tell you the rebate is "ending next month" to rush you: it steps down gradually, every January, and that's been the schedule for years.

See your price after the rebate

The calculator applies the STC discount for your zone automatically — enter your bill and postcode to see your system's real out-of-pocket cost.

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Last updated: September 2026.

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