How to Read a Solar Quote: What to Compare Before You Sign

When you request solar quotes, the first few can feel reassuringly straightforward. A system size. A dollar figure. Some brand names you may or may not recognise. A rebate that's already been applied. Easy enough.

Then you put two or three quotes side by side and things get murky fast. One is $2,000 cheaper, but is it worse? One mentions “battery-ready” while another doesn't. Warranty lengths differ. Inverter brands you've never heard of sit alongside ones you have. Suddenly the decision doesn't feel simple at all.

The good news: once you know what each section of a solar quote actually means, comparing them becomes far more manageable. This guide walks through the key areas to check, the questions worth asking, and the spots where important differences tend to hide.

Every solar quote leads with a system size, usually expressed in kilowatts (kW). A 6.6kW system is the most common residential size in Australia, while 10kW and 13kW systems are increasingly popular for larger households or those planning to add a battery.

That headline number tells you the total panel capacity, but it does not tell you how much energy your household will actually use, or how well the system fits your daily consumption pattern. A larger system generates more power, but if your inverter caps output or most of your excess gets exported at a low feed-in tariff, you won't see a proportional return on the extra cost.

A good quote explains why a particular system size suits your home. If it just lists a number with no context about your usage, roof orientation, or export potential, that's worth questioning.

Panel brands tend to get the most attention in solar quotes, and for good reason. They're the most visible part of the system, sitting on your roof for 25 years or more. But the brand alone doesn't tell you everything.

When reviewing panel details, check the total number of panels and their individual wattage. A 6.6kW system might use 15 panels at 440W or 16 panels at 415W. The difference seems minor, but it affects how they fit on your roof and how the system performs under partial shading.

If panels are the most visible part of a solar system, the inverter is the most important. It converts the DC electricity your panels produce into AC electricity your home can use. It also determines what monitoring you get, whether you can add a battery later, and how efficiently the system performs overall.

This is the component where quotes differ the most, and it's often the reason one quote is significantly cheaper than another. A budget string inverter might cost $800, while a premium hybrid inverter with battery compatibility and detailed monitoring could run $2,500 or more. Both will work, but they offer very different experiences over the next 10 to 15 years.

Battery assumptions are one of the most common sources of confusion in solar quotes. Some quotes include a battery. Some say the system is “battery-ready.” Some don't mention batteries at all. These are three very different propositions.

If a battery is included, check the usable capacity (not just the total capacity, as some energy is held in reserve), whether it provides backup power during outages, and the warranty conditions. Battery warranties typically guarantee a certain number of cycles or years, whichever comes first.

If the quote says “battery-ready,” that usually means the inverter is a hybrid model that can accept a battery later. This is genuinely useful, but worth confirming. Ask which battery brands are compatible and what the additional cost would be to add one down the track. Some “battery-ready” systems require specific batteries from the same manufacturer, which limits your options.

Most solar quotes in Australia show a “discounted” price that has already factored in Small-scale Technology Certificates (STCs). These are a federal government incentive that reduces the upfront cost of solar. For a typical 6.6kW system, the STC discount is roughly $2,500 to $3,000, depending on your location and the current certificate price.

The key things to check in this section of the quote are straightforward. Confirm whether the STCs have been deducted from the displayed price (almost always yes, but worth verifying). Check who is handling the STC assignment. In most cases the installer manages this on your behalf, meaning you sign over your STCs and they reduce your upfront cost accordingly. If the installer expects you to claim them separately, that's unusual and worth clarifying.

If your state offers additional rebates (Victoria's Solar Homes program, for example), check whether those have been applied to the quoted price or whether they're separate. A clear quote shows the full system price, itemises the STC discount and any state rebates, and arrives at the final out-of-pocket cost with nothing left vague.

This is an area where many homeowners don't think to look, but it matters. Some solar companies employ their own installation teams. Others subcontract to third-party installers. Neither approach is inherently better, but you should know who is actually on your roof and whether they're properly accredited.

A solid quote will confirm that the installer is Clean Energy Council (CEC) accredited, which is a legal requirement for the installation to qualify for STCs. It should also cover who handles the electrical compliance certificate and the grid connection application with your electricity distributor. These steps happen after the physical installation and can take a few weeks. Knowing the expected timeline upfront avoids frustration later.

Solar quotes often highlight impressive warranty numbers. Twenty-five years on the panels. Fifteen years on the inverter. It looks reassuring, and in many cases it is. But there are two distinct types of warranty at play, and understanding both matters.

This is where price differences between quotes often tell their real story. A cheaper quote might save you $500 upfront, but if it comes with no monitoring, slow response times, and nobody to call when your system stops exporting, that saving evaporates quickly.

Check what monitoring is included. Most modern inverters offer app-based monitoring that shows real-time generation, consumption, and export data. Some installers set this up as part of the job, while others leave it to you. Monitoring is genuinely useful because it's how you'll spot problems early, like a sudden drop in output that could indicate a faulty panel or inverter issue.

Ask about expected response times for support enquiries and whether there's a local contact or just a national call centre. Good post-installation support can matter more than small upfront savings, especially over the 10 to 25 year lifespan of the system.

There's nothing wrong with a budget solar quote. Not everyone needs a premium hybrid inverter or top-shelf panels. But you should understand what trade-offs are being made to arrive at that lower price.

Common ways cheaper quotes reduce cost include using a basic string inverter without battery compatibility, shorter workmanship warranties, minimal or no monitoring setup, and reduced after-sales support. None of these are deal-breakers on their own. A string inverter is perfectly fine if you have no plans to add a battery. A shorter warranty is acceptable if the installer has a solid track record. The important thing is making that choice knowingly rather than discovering the trade-offs after the system is on your roof.