What a solar system costs, and what drives the number

The most-asked question about solar is what it costs, and it is the one this site deliberately does not answer with a number.

Why there is no figure on this page

Everything published here is either read off a named source on a stated date, or shown as a gap. That is the standard the 8 power companies we compare are held to, where an unverified field renders as "Not confirmed" rather than being quietly filled, and solar does not get an exception because the question is popular.

We hold no verified installer pricing. So we publish none.

There is a second reason, and it is practical rather than principled: a published price range becomes an anchor. Someone who reads a number here and then receives a quote above it assumes they are being overcharged, when the difference may be entirely explained by a two-storey roof and a switchboard that needs replacing. The range would do more harm than the gap.

What actually drives the number

System size, in kilowatts. The obvious one, and less decisive than people expect, because the per-kilowatt cost falls as size rises.

Roof access and type. A single-storey house with a simple long-run roof is a straightforward day. A two-storey with a tile roof and scaffolding requirements is a different job entirely, with the same panels on it.

Switchboard and wiring. Older switchboards frequently need work before generation can be connected. This is one of the largest single swing factors between two quotes and it is often a line item you have to ask about.

The inverter. Specification varies widely, and a hybrid inverter — one that can take a battery later, or provide backup during an outage — costs more than a plain string inverter. Whether you need one is a real decision, not an upsell by default.

Network application and meter change. Connecting generation needs your lines company's approval, and your meter may need replacing to record export. Some quotes include this and some do not.

Whether a battery is in the price. Batteries typically cost a substantial fraction of the whole system and are a separate economic decision.

Comparing two quotes fairly

Put them on the same footing before comparing totals:

1. Same size, stated in kW of panel capacity, and same panel count.
2. Same inclusions. Scaffolding, switchboard work, network application, meter change, consent if required. Ask each installer for the exclusions explicitly, because that list is more informative than the inclusions.
3. Same production assumption. Ask for modelled annual kWh and the assumptions behind it: orientation, pitch, shading. An optimistic model makes a payback calculation look good without changing anything physical.
4. Same warranty terms, separated into panels, inverter and workmanship. They are usually three different periods from three different parties.
5. Same battery position: in or out, on both.

The number that matters more than the price

What the system produces that you use, rather than export. Every unit consumed at home displaces electricity at your retail rate — 42.04c per kWh nationally as at May 2026, and higher in expensive network areas — while every exported unit earns the buy-back rate instead.

Two identical systems on two identical roofs can have very different returns depending on whether anyone is home at midday. That is worth more attention than a few hundred dollars on the quote, and it is the subject of the worth-it page.