Solar panels in Erina

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 2250 already taken off. Those are typical figures for a straightforward install, not a fixed price. The inverter is where a meaningful price difference between quotes usually hides, so it is worth knowing which one you are being offered and what its warranty term is.

Erina 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. The certificates are calculated on the panel capacity rather than the inverter, which is part of why arrays are routinely larger than the inverters they feed.

Because that is good design rather than a corner being cut, and because the scheme allows it. An array may be up to 133% of the inverter's AC rating and still qualify for certificates — 6.6kW of panels on a 5kW inverter is a ratio of 132%, comfortably inside it. The reason it is worth doing is that panels almost never produce their rated output: the nameplate figure is a laboratory rating taken at full sun and a 25°C cell temperature, and a real roof rarely offers both at once. A slightly oversized array keeps the inverter working in its efficient band through more of the morning and afternoon rather than idling.

A little, and much less than people expect. When the array briefly produces more than the inverter can convert, the inverter holds its output at its limit and the surplus is simply not harvested — that is called clipping. At the ratios used in Australia the annual loss is typically around one per cent, because the conditions that cause it are a handful of hours around midday on clear cool days. You lose that one per cent and gain output across every other hour of the year. It is a trade that pays.

A string inverter is one box on the wall that converts the whole array, and it is the standard and cheapest arrangement. A hybrid inverter is a string inverter that can also charge and discharge a battery, so it is what you want if storage is likely later. Microinverters sit under each panel and convert on the roof, which helps where panels face different directions or one of them is shaded, and costs more. None of them is the right answer universally — the roof decides, and anyone selling you microinverters for an unshaded north-facing roof is selling, not designing.

Often yes, and it is the cheapest decision you will make about a future battery. Retrofitting storage to a plain string inverter usually means adding a second piece of hardware or replacing the inverter outright, and the difference in price at install time is far smaller than that later. The honest caveat is that it only pays if the battery actually happens — if you are confident it will not, do not pay for the capability. Our 10kW package is specified hybrid-ready for exactly this reason.

Less than the panels, and that is normal rather than a defect. Panels degrade slowly by design and generally outlive their warranties; inverters are electronics working hard every day and they stop outright, which is why a system that has gone dark is almost always an inverter problem rather than a panel problem. Warranty terms run from about five to twelve years depending on the brand, and some can be extended at purchase. Plan on replacing one at some point in a twenty-five year system, and treat that as the cost of owning solar rather than a surprise.

The distribution network that owns the poles and wires in your street approves it — not your retailer — and we lodge the application for you. The number the network assesses is the inverter's AC rating rather than the panel capacity, which is another reason the two figures differ. On a flexible export connection, a complying system up to 30kW is automatically approved to export up to 10kW per phase; on a fixed export connection the approval is 3kW per system, and with no reliable internet at the property a static 1.5kW limit applies until a connection is available.