Is solar worth it in Australian Capital Territory? Payback for 2026–27
Typical 6.6 kW system · Canberra (STC Zone 3)
Annual benefit ≈ $1,870 ($1,350 bill savings + $520 exports) · 10-year position ≈ $12,200.
Every assumption below is a dataset value — change any of them in the calculator.
Solar payback calculator
ACT6.6 kW is the most common residential size.
Pre-set: Retailer-set — no government minimum.
- Annual generation (3.79 kWh/kW/day, STC Zone 3)
- 9,130 kWh
- Bill savings (self-consumed at 37.0c/kWh)
- $1,350/yr
- Export earnings (9.5c/kWh feed-in)
- $520/yr
- Total annual benefit
- $1,870/yr
- Net cost
- $6,500
- 10-year position
- $12,200
Your quote already includes ≈$1,796 of STC discount (45 STCs at $39.9 each) — it is not subtracted again.
Assumptions: CER-derived generation factor, ACT reference usage rate (ICRC retail electricity price recalibration 2026–27 (ActewAGL standing offer)), STC spot $39.9 as at 10 July 2026, deeming to the 2030 scheme end. Panel degradation, tariff changes and finance costs excluded. How these numbers are built →
The assumptions, sourced
| Input | Value | Source |
|---|---|---|
| Daily generation per kW | 3.79 kWh | CER zone rating, derived (Zone 3) |
| Usage tariff offset | 37.0c/kWh | ICRC retail electricity price recalibration 2026–27 (ActewAGL standing offer) (Evoenergy) |
| Feed-in tariff | 9.5c/kWh | Retailer survey median, 17 July 2026 |
| Self-consumption | 40% | Editable assumption (typical daytime-home share) |
| STC value | $1,796 | 45 STCs × $40 spot (10 July 2026) |
| Price basis | post-STC | AU quotes include the STC discount — not subtracted again |
How the numbers are built
Generation = kW × the CER-derived daily factor × 365. The share you use directly offsets power at your usage rate; the rest exports at the feed-in rate. Net cost is your quote minus any upfront state rebate — and minus the STC value only if your quote was genuinely pre-STC, which Australian quotes almost never are. Payback = net cost ÷ annual benefit. Full formulas on the methodology page.
Frequently asked questions
- How many years to pay back solar in ACT?
- About 3.5 years for a typical 6.6 kW system quoted at $6,500 (a post-STC price), self-consuming 40% — an annual benefit of ≈$1,870. Your roof, usage pattern and quote move it; change every input in the calculator above.
- How is the STC rebate worked out?
- kW × zone rating (1.382 in Canberra, Zone 3) × deeming years (5 for a 2026 install), rounded down, × the certificate price ($40). For this system that's 45 STCs ≈ $1,796 — already inside a normal Australian quote, which is why the calculator doesn't subtract it again by default. Full detail: ACT solar rebates.
- Does the feed-in tariff still make solar worth it?
- The FiT is no longer the engine — at 9.5c/kWh, exports earn ≈$520/yr here versus ≈$1,350/yr from self-consumption at 37.0c/kWh. Payback now lives on the power you don't buy, not the power you sell. See current ACT FiT rates.
- Is a battery worth adding?
- A battery converts low-value exports into high-value self-consumption, and the federal Cheaper Home Batteries Program discounts a VPP-capable battery via STCs (roughly a third off). It lengthens the combined payback versus panels alone in most homes, but the gap has narrowed — the case is strongest where the FiT is lowest. Scheme detail: ACT rebates.
Related
- ACT solar rebates
- ACT feed-in tariff
- ACT electricity prices
- Solar in NSW
- Solar in VIC
- Solar in QLD
- Solar in SA
- Clean Energy Regulator — STC zone ratings & deemingverified
- ActewAGL — schedule of standard contract electricity prices from 1 July 2026verified
- SunTariff quarterly retailer FiT survey
- Ecovantage certificate market update (REC Registry spot)cross-checked
Panel degradation, tariff escalation, financing costs and export limits are excluded — the estimate is conservative on generation (CER-deemed factor) and neutral on prices. Not solar-purchase advice.