Every 1 January the number of years of generation that the rebate pays for goes down by one. On 1 January 2027 it goes from 5 to 4.
The size of the 2027 cut
Fewer deeming years means fewer certificates. The cut is 20 per cent on any size of system in any zone. For a 6.6 kW system:
| Zone | 2026 STCs | 2027 STCs | Difference at $38 to $40 |
|---|---|---|---|
| 1 | 53 | 42 | about $410 to $440 |
| 3 | 45 | 36 | about $340 to $360 |
| 4 | 39 | 31 | about $300 to $320 |
These are approximate and round down.
What to do before the date
- Get a quote that includes a commissioning date, not just a start date.
- Ask what happens if the install slips past 31 December: does the price go up?
- Check network approval and meter requirements early, because they commonly cause delays.
- If you want a battery as well, note that the battery factor also falls on 1 January 2027, from 6.8 to 5.7, with another step to 5.2 on 1 July 2027.
Should you rush?
A $340 reduction on a typical system is real money, but it is only a fraction of the total cost. Do not accept a rushed install, a sloppy design or a pushy deadline to save it. A good system that is installed well in February is better than a poor one in December.
If your install slips into January
If your installation slips past the date, ask whether the installer will absorb the difference or pass it on. Sometimes the cause was a delay by the network or the customer, and sometimes it is the installer’s scheduling. The contract should say what happens in each case, which is one more reason to read it before you sign.
What this means for you
Decide on the system first, then on the timing. See the schedule by year, should I install solar now or wait, and the 2027 changes. The STC trading pillar explains how the scheme works from the installer side.