The STC scheme is not ending tomorrow, but it is winding down on a fixed schedule. It was designed so that the benefit now steps down every six months to 2030, ending on 31 December 2030. The date is set in legislation, and nothing in the current settings changes it.
The step-down, year by year
The deeming period is the number of years of expected generation that an STC claim pays for. It reduces by one each calendar year.
| Install year | Deeming period | 6.6 kW, zone 3 STCs |
|---|---|---|
| 2026 | 5 years | 45 |
| 2027 | 4 years | 36 |
| 2028 | 3 years | 27 |
| 2029 | 2 years | 18 |
| 2030 | 1 year | 9 |
The count falls by about a fifth in the first step, and by a quarter and more in later ones. See what changes in January for the next change.
What about batteries and hot water
The Cheaper Home Batteries Program has its own factor, which was 6.8 per kWh for 2026 installs and steps down to 5.7 on 1 January 2027 and 5.2 on 1 July 2027, and keeps stepping down every six months to 2030. Hot water and heat pumps follow the scheme’s own rules, so check the current method. See battery STCs.
What to do now
If you are planning solar, decide on an install window and ask your installer to confirm the date in writing. If you are an installer, plan your pipeline so that jobs which can be safely completed before the year end are. Beyond that, there is little to gain from guessing what the market will do near 2030.
What this means for the market
A shrinking number of certificates per system means the volume in the market will fall over time. Price is anchored by the $40 ceiling now, but the scheme’s end brings uncertainty. Nobody can say precisely what the price will do.
From the desk: the practical effect for customers is the January cliff each year. A job that is installed on 2 January can be worth a fifth less than one installed on 31 December.
What this means for you
If you are a homeowner or business thinking about solar, plan the installation date rather than panic. If you are an installer, bring forward the jobs that can safely be completed in December. See STC trading, pricing and what an STC is worth.