The word “rebate” is a bit loose. What Australia actually runs is the Small-scale Renewable Energy Scheme, which hands out one STC for each megawatt hour of electricity your system is expected to produce over a set number of years. Those certificates are worth money, and your installer turns them into a discount on your quote.
How the number is worked out
The Clean Energy Regulator uses a simple formula. Your system size in kilowatts is multiplied by the zone rating for your postcode, then by the number of years remaining in the scheme, called the deeming period. For installs in 2026 the deeming period is five years, it drops to four in 2027, and it falls by one each year until the scheme ends on 31 December 2030.
The four zone ratings are 1.622, 1.536, 1.382 and 1.185, with sunnier northern areas rated higher. The result is rounded down to a whole number of STCs. Our deeming period and zone ratings guide has the detail.
Who does the paperwork
You do not register or lodge anything. Your accredited installer creates the STCs in the Clean Energy Regulator’s registry after installation, then sells them to a certificate trader. You sign an assignment form that gives them the right to do this, and in exchange the price of your system drops by the expected value of the certificates. The step-by-step version is in how to claim the solar rebate.
What the discount is worth
STCs trade on a market, so the figure moves. At the time of writing the spot price has been roughly $38 to $40, with the clearing house ceiling at $40. A typical 6.6 kW system in a mid-rated zone earns around 45 STCs, which is a discount in the region of $1,700 to $1,800. The worked example is in how much the rebate is for 6.6 kW.
From the desk: the rebate shrinks every 1 January because the deeming period steps down. A quote signed in December and installed in January can be worth less than you expected. Ask your installer when the system will actually be installed and registered.
What this means for you
Compare quotes on the final price after the STC discount, and ask each installer to show the STC count and the dollar value they have used. If you want the wider picture of how certificates work, the resources hub covers the lot, and what an STC is worth explains how the price is set.