Solar panels in Kellyville Ridge

As an estimate, a 6.6kW system comes to about $3,990, a 10kW to about $5,490 and a 13.2kW to about $7,990, with the STC discount for postcode 2155 already taken off. Those are typical figures for a straightforward install, not a fixed price. Panel choice moves this number less than most people expect — the gap between a competent mid-market panel and a premium one is usually smaller than the gap between two installers quoting the same panel.

Kellyville Ridge is in STC Zone 3, rating 1.382. In 2026 a 6.6kW system creates 45 certificates, worth roughly $1,710 off the price, and a 10kW system 69 certificates, roughly $2,622. It is a discount applied at the point of sale, not a grant you apply for afterwards. It depends on system capacity and postcode only — the brand of panel makes no difference to it at all.

It is a bankability ranking of manufacturers published by BloombergNEF, and it describes the company's finances rather than the panel's quality. A manufacturer makes the list when its modules have been used in at least six different projects financed by six different non-recourse banks over the preceding two years. BloombergNEF itself says plainly that the list should not be used as a measure of quality, and that it is a snapshot for one quarter rather than a product endorsement. It was built for financiers deciding whether to lend against a solar farm, not for a household choosing between two panels. We use the term on this site ourselves, which is exactly why it is worth explaining what it does and does not tell you.

Not at all — it is just a weak signal, not a specification. A manufacturer large and solid enough to appear on that list is more likely to still exist when you make a warranty claim in twelve years, and that genuinely matters. What it does not tell you is how much power the panel makes, how fast it degrades, how it behaves on a hot roof, or what the warranty actually promises. Treat it as a comment on the company and then look at the four numbers below, which are comments on the panel.

Four figures, all of them on the manufacturer's datasheet, all of them free to look up. Efficiency, which tells you how much power you get per square metre of roof — it matters when the roof is small and barely at all when it is not. The degradation rate and the year-25 guarantee, which is how much output the maker promises still remains after twenty-five years. The temperature coefficient, which is how much output you lose per degree above the 25°C rating and matters a great deal on a dark roof in a Sydney February. And the product warranty term, which is separate from the performance warranty and is the one people confuse.

No — the inverter is the part that decides most of what you experience, and it is the part that fails. Panels degrade slowly by design and usually outlive their warranty; inverters stop outright, and when a system goes dark the inverter is almost always why. It is also the component that determines whether you can add a battery later without replacing hardware. If you are going to spend extra anywhere, the evidence points at the inverter rather than the panels.

Ask for the make, the model and the count, in writing. “Premium European”, “German engineered” and “Tier 1” are not specifications and cannot be checked — a great many panels are designed in one country and built in another, which is normal and not a scandal, but it does mean the adjectives tell you nothing. A make and model number tells you everything, because the datasheet is public. An installer who will not put the model on the quote has given you an answer.

The distribution network that owns the poles and wires in your street approves it — not your retailer — and we lodge the application for you. That network also decides how much your system may export: on a flexible export connection, eligible customers can send up to 10kW per phase back to the grid most of the time, while a fixed export limit caps exports at 1.5kW. Equipment choice does not change your export approval, but it does have to be on the approved product lists the scheme and the network rely on — which is a genuine quality gate, and a different one from the tier list.