6.6 kW solar system cost (after STCs)
A 6.6 kW rooftop system is still the yardstick many Australian quotes use. Panel and inverter prices have fallen for years, while the STC deeming period keeps shrinking toward 2030 — so net cost is a race between hardware deflation and fewer certificates. Verified data stamp on related rebate files: 12 July 2026.
Typical installed price
Our planning mid-point for a straightforward 6.6 kW install is about $6,500 before STCs. Tier-one hardware, tile roofs, and long DC runs sit higher; bare promotional “from” prices sit lower and often exclude extras.
Illustrative STC discount
| Line | Value |
|---|---|
| Typical installed | $6,500 |
| STCs (floored) | 36 |
| Assumed net $/STC | $37 |
| Illustrative STC discount | $1,332 |
| Illustrative net | $5,168 |
More detail on zones and deeming: solar panel rebate (STCs).
What drives quotes up or down
- Panel tier and inverter brand / hybrid readiness
- Roof type, storeys, and split arrays
- Export limits and meter upgrades
- Council or strata constraints
- Whether an electrician must upgrade the main switchboard
Adding a battery later or together
Hybrid inverters cost more upfront but simplify a later battery. If you are buying both now, demand separate STC (panels) and Cheaper Home Batteries (battery) lines. Start with 13.5 kWh battery cost or the Perth package page.
Sources
Frequently asked questions
Is 6.6 kW still a sensible default?
It remains a common single-phase sweet spot, but many homes now quote 8–10 kW if the switchboard and export limits allow. Match array size to daytime load and roof — not to a 2018 rule of thumb.
Does this include a battery?
No. This page is panels-only. For combined packages see the Perth solar + battery page; battery support uses the separate Cheaper Home Batteries Program.
Why is my STC discount different?
Zone rating, exact deeming factor, and certificate price on the day all move. Our example is illustrative using the same net STC assumption as our battery maths.