Solar is one of the few purchases where the headline price tells you almost nothing. The same roof can attract quotes thousands of dollars apart, and the gap is rarely about margin. It is about component quality, design effort, and what has been quietly left out. Here is how to compare like an engineer.
1. The panel and inverter brand, in full
A quote should name the exact panel model and the exact inverter model, not 'tier 1 panels' or '6.6kW system'. Those phrases are marketing, not specification. If the brand is not pinned down, you cannot check its warranty, its track record, or whether the company that backs it still exists in Australia.
2. Two warranties, not one
- Product warranty covers the hardware itself failing. Panels are typically 12 to 25 years, inverters 5 to 10.
- Performance warranty guarantees the panel still produces a set percentage of its rated output after 25 years.
- Workmanship warranty covers the installation. This is the one cheap quotes quietly shorten.
A 25-year panel warranty is worthless if the installer who has to honour it will not be trading in three years. Buy the company as much as the panel.
3. The design, not just the size
A 10kW system facing the wrong way, or split across a shaded roof face on a single string, can underperform a smaller system designed properly. A good proposal shows panel placement, string layout, and an annual generation estimate based on your roof's orientation and tilt, not a national average.
4. What is missing
The cheapest quote often excludes the things that make an install safe and compliant: switchboard upgrades, optimisers for shaded sections, proper cable runs, and meter reconfiguration. When those appear as a surprise on install day, the cheap quote becomes the expensive one.
Our proposals are built by SAA-accredited engineers and itemise every component and assumption, so you can compare them against anyone else's with confidence.
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