What actually drives the price
System size is only one input. Two houses in the same street can differ by thousands depending on the details below.
- Panel and inverter tier — a budget inverter versus a Sungrow, GoodWe or Sigenergy unit is a real cost difference, and a real reliability difference.
- Roof type and pitch — tin is quicker than tile; tile and slate cost more in labour and fixings.
- Storeys and access — two-storey or steep blocks need more edge protection and time.
- Number of roof planes — splitting an array across three or four orientations means more rail, more optimisation and sometimes more inverter inputs.
- Switchboard condition — older boards often need a safety switch or main-switch upgrade before the grid connection is approved.
- Distance from the board to the array — long cable runs add cost and can affect voltage drop.
- Single-phase versus three-phase supply — three-phase opens up bigger inverters but the hardware costs more.
How the federal rebate changes the number you pay
The federal Small-scale Renewable Energy Scheme creates Small-scale Technology Certificates (STCs) based on your system size, location and the year of install. Almost every installer applies that value as an up-front discount, so the price you're quoted is usually already net of it.
The number of certificates a system earns steps down each year until the scheme ends, so the same system generally attracts a slightly smaller discount each January. Batteries sit under a separate federal program with its own rules.
When you compare quotes, check whether the figure you're looking at is before or after STCs — that alone explains a lot of apparent price gaps.
What to check before you sign anything
- The exact panel and inverter model numbers, not just a brand name or "tier one".
- Who physically installs it — an in-house CEC-accredited installer, or a subcontracted crew from out of the region.
- Workmanship warranty length, and whether that installer will still be around to honour it.
- A production estimate for your specific roof, with shading accounted for — not a generic figure.
- Whether the grid application, metering and network paperwork are included.
- Whether the inverter is battery-ready if you might add storage later.
Payback on the Sunshine Coast
South-east Queensland gets strong year-round sun, which is why local payback periods compare well with most of the country. The single biggest factor is self-consumption: every kilowatt-hour you use yourself is worth far more than one you export at the feed-in rate.
If nobody's home during the day, shifting the dishwasher, pool pump and hot water to the middle of the day will do more for your return than buying a bigger array. If you can't shift that load, a battery is usually the better next step.
We'll give you a payback estimate against your actual bill rather than a brochure figure — try the calculator on this site for a rough starting point, then ask us to check it properly.
Common questions
Is a cheap solar system worth it?
It can be, if the equipment is reputable and the install is done properly. The failures we get called out to are almost always cheap inverters or rushed installs — not cheap panels.
Do I pay the rebate back later?
No. The STC value is applied as an up-front discount on your invoice; there's nothing to repay.
Can I pay in instalments?
Ask us — there are finance and payment-plan options available, and we'll tell you honestly whether the repayments will be lower than the bill savings.
Want this checked against your own bill?
We'll give you a system size, price and payback estimate for your actual roof and usage.