How to Compare Solar Quotes in Brisbane: What Should Be Included?

Solar panels installed on the roof - Sinnamon Park, Brisbane

Three quotes for “a 10kW solar system” can come back at $8,200, $9,800 and $13,400 — and all three can be honest. The spread usually is not someone trying it on. It is that the three quotes are describing three different jobs, and quote documents are rarely laid out in a way that makes those differences obvious.

So here is how to read a Brisbane solar quote properly: what has to be on it, what the numbers actually mean, and the handful of questions that separate a good price from a merely cheap one.

First, convert every quote to a price per kilowatt

Before you compare anything else, divide the installed price by the system size in kilowatts. It is the only way to put quotes of different sizes side by side.

A $9,000 quote for 10kW and a $12,000 quote for 13.2kW look wildly different until you do the sum: $900 and $909 per kilowatt. They are effectively the same price. One is simply a bigger system.

For reference, our own Brisbane solar pricing currently runs from roughly $605–$832 per kW on a 6.6kW system up to $757–$946 per kW at 13.2kW, after the federal discount. Note that per-kilowatt cost does not keep falling as systems grow — bigger systems need heavier inverters, more mounting hardware and more electrical work.

Per-kilowatt is the first filter, not the verdict. A quote well under the range is telling you something about the equipment or the labour, and the rest of this article is about finding out which.

What a Brisbane solar quote should include

At minimum, a quote you can actually evaluate will name:

Panel make, model and wattage, and the exact number of panels
Inverter make, model and capacity
Total system size in kW, and an annual generation estimate in kWh
Mounting system and the roof type it has been priced for
Scope of electrical work — switchboard, isolators, cabling run, metering
Three separate warranties, with terms, not just a single headline number
The STC discount shown as its own line, not folded invisibly into the price
Who performs the installation, and their accreditation

If any of those are missing, the gap itself is the useful information. Ask for it in writing before you compare.

Panel and inverter specifications, by make and model

“Tier 1 panels” and “premium European inverter” are not specifications. Tier 1 is a bankability ranking of manufacturers’ financial stability — it says nothing about how a given panel performs on your roof.

You want the model number. With it you can check the panel’s efficiency, its temperature coefficient (which matters more in Brisbane than in Melbourne — panels lose output as they heat up) and the actual warranty document rather than a salesperson’s summary.

The inverter deserves equal attention, because it is the component most likely to need replacing first. Check its capacity against the array: a 10kW array on an 8.5kW inverter is a deliberate, sensible bit of oversizing, but you should know it is there. Check whether it has dual MPPT if your roof faces more than one direction, and check whether it is hybrid — that is, battery-capable — if storage is anywhere in your plans.

If you want to see how different panels behave in the same conditions rather than on paper, we built a 16-panel test array for exactly that.

System size and a generation estimate you can check

Two different units get used loosely and they are not interchangeable. Kilowatts (kW) is the system’s capacity — its maximum output. Kilowatt-hours (kWh) is energy produced over time, and it is what your bill is measured in.

A quote should give you both: the size in kW and an estimated annual yield in kWh. That estimate is checkable. A well-oriented Brisbane system typically lands somewhere near 1,400 kWh per kW per year — a 6.175kW system we installed at Ferny Hills produces 8,698 kWh annually, which works out at about 1,409.

If a quote projects substantially more than that, ask what assumptions produced it. If it projects substantially less, there may be a shading or orientation issue the installer has quietly priced in but not explained.

Size should be driven by when you use power, not just how much. A household that is empty from 8am to 6pm gets a very different answer from one running air conditioning all afternoon.

The installation, not just the hardware

This is where quotes diverge most and disclose least. Two installers pricing identical equipment can be thousands apart because one has looked at your switchboard and the other has not.

Things that legitimately change the price: tile versus tin roof, single versus double storey, the condition and capacity of your switchboard, how far the cable has to run from array to inverter to board, whether your meter needs reconfiguring, and what height-safety equipment the job requires.

The questions worth asking are simple. Has someone physically inspected the roof and switchboard, or is this priced off satellite imagery? Is switchboard upgrade work included, or is it a variation you will be billed for on the day? Who handles the Energex connection approval and the paperwork?

A quote issued without a site inspection is an estimate wearing a quote’s clothes. Ours are confirmed in writing after an inspection, precisely because roof type, storey height and switchboard condition all move the number.

Three warranties, not one

“25-year warranty” on the front page of a quote is close to meaningless, because there are three separate warranties and they cover different things.

Product warranty — covers the panel itself against defects. Typically 12 to 30 years depending on the manufacturer.
Performance warranty — guarantees the panel still produces a stated percentage of its rated output after a given period, commonly around 25 years. This is the one usually quoted in advertising.
Workmanship warranty — covers the installation itself: the mounting, the sealing, the electrical work. This is the one that matters most in the first five years, and the one most often left vague.

The inverter carries its own separate warranty, usually shorter than the panels — frequently 5 to 12 years, sometimes extendable.

Then the question behind all of them: who actually honours the warranty? A manufacturer’s warranty requires someone to diagnose the fault, remove the panel, deal with the manufacturer and refit it. If the installer has gone, that labour is yours to arrange and pay for. Ask how long the business has been operating in South East Queensland, and who you call in year seven.

Battery-ready or battery-inclusive?

“Battery-ready” is one of the loosest terms in the industry. Sometimes it means a hybrid inverter is installed and a battery can be added with minimal rework. Sometimes it means nothing more than that a battery could theoretically be installed later, which is true of every house in Queensland.

Ask specifically: is the inverter hybrid, and what battery capacity does it support? What would adding storage later actually involve — and cost?

One trap worth knowing about if backup power is part of your thinking. A battery alone will not keep your lights on in an outage. Grid-connected inverters are required to shut down when the grid goes down, and running your home from stored energy needs a separate piece of switching hardware. We wrote that up in detail in blackout protection in Brisbane. If backup matters to you, it has to be in the quote — retrofitting it later means switchboard work and another round of approvals.

For what storage actually costs and how it is sized, the Brisbane battery storage guide covers it properly.

How rebates should appear on your quote

There is no Queensland state solar rebate. The incentives available here are federal, and they apply in every postcode — so a quote claiming access to some exclusive local scheme is a flag, not a bargain.

Small-scale Technology Certificates are the main one. Most households assign them to the installer in exchange for a discount applied directly to the quote, which means you never claim anything or wait for a refund. On a well-presented quote the STC value appears as its own line so you can see both the gross price and what you actually pay.

If storage is included, the federal Cheaper Home Batteries Program covers roughly 30% of an eligible battery’s cost. Two details matter when you are comparing: a tiered structure introduced on 1 May 2026 reduces the rate applied to larger batteries, and the rebate steps down every six months — so a quote and an installation date months apart may not attract the same amount. Ask which step the quoted figure assumes.

Our Queensland rebates guide sets out both schemes, including what has changed recently, since a fair amount of out-of-date advice is still circulating.

Questions to ask before you accept a quote

What is the price per kilowatt, and what explains the difference from the other quotes?
What are the exact panel and inverter models, and can I see the warranty documents?
Has anyone inspected the roof and switchboard, or is this priced remotely?
Is switchboard work included, or billable as a variation on the day?
Who physically carries out the installation, and are they accredited?
What are the product, performance and workmanship warranties — separately?
What is the annual generation estimate, and what assumptions produced it?
Is the inverter hybrid, and what does adding a battery later involve?
What STC value is applied, and is it shown as a line item?
Who handles the Energex connection approval?

If an installer is reluctant to answer any of these in writing, that answer is itself informative.

How we quote

We put the specifications on the page — panel and inverter make and model, system size, generation estimate, the scope of electrical work, and each warranty separately. The STC discount appears as its own line so you can see the gross price and the net. Pricing is confirmed in writing after a site inspection rather than estimated from aerial imagery, because the switchboard and the roof are where the surprises live.

We would also rather you compared our quote properly against the others than accepted it quickly. A quote you understand is one you will not be arguing about in year three.