On 1 January 2026 the federal Small-scale Technology Certificate (STC) deeming period stepped down from 5 years to 4 years. That's a roughly 25% reduction in the dollar value of the federal solar rebate for any system installed during 2026, and the step-down repeats every January until the scheme phases out completely on 31 December 2030.
What this means in dollars
For a typical 6.6 kW system in Sydney (STC Zone 3, rating 1.382), the federal STC rebate is now:
- 2025 install: 6.6 × 1.382 × 5 × $38 = $1,733
- 2026 install: 6.6 × 1.382 × 4 × $38 = $1,386
- 2027 install (projected): 6.6 × 1.382 × 3 × $38 = $1,040
- 2028 install (projected): 6.6 × 1.382 × 2 × $38 = $693
The dollar-value step-down is bigger in absolute terms in higher STC zones — the NT (Zone 1, rating 1.622) loses about $407 per kW step-down, vs. about $277 per kW in Tasmania (Zone 4, rating 1.092).
Why is the rebate winding down?
The STC scheme was legislated under the Renewable Energy (Electricity) Act 2000 with a fixed end date of 31 December 2030. The "years remaining" multiplier in the rebate formula reflects how many years of expected generation can still be claimed at install. As we approach 2030, the multiplier ticks down each January.
Should you wait or install now?
The maths is clear: every year you delay costs about a quarter of the federal rebate value, in cash. Other rebate programs aren't growing to compensate — most state programs are also winding down (see other updates on this page). For most homeowners considering solar in 2026, installing before the next 1 January is measurably better than waiting.