Before You Sign: 5 Questions to Ask a Solar Installer, Stage by Stage
Solar
Before you get a single quote, confirm five things: the installer holds current SAA and CEC accreditation, they’ve done a physical site visit rather than a desktop quote, the quote is itemised with exact component models and warranty terms, you know whether their own staff or a subcontractor does the install, and you know who’s handling the grid connection paperwork. Get several written quotes to compare your options. Never hand over a large deposit without a signed, itemised contract in hand.
TL;DR:
- Verify the installer’s current SAA and CEC accreditation numbers online, as many claim accreditation but may not hold valid credentials.
- Ensure they conduct a physical site visit to assess roof condition, shading, and wiring before providing a detailed, accurate quote.
- Request specific component model numbers and warranty details for panels, inverters, and batteries to evaluate quality and after-sales support.
- Obtain an itemised quote covering parts, labour, and rebates, and compare at least three to identify risks of inferior components or rushed installations.
- Confirm who handles the grid connection paperwork and require written agreements for any unexpected issues or variations during installation.
Table of Contents
- Questions to ask a solar company about their credentials
- Site visit and system sizing questions to ask
- Component brands, model numbers and warranty terms
- Cost, rebates and payback: what to nail down before signing
- What to expect on installation day
- After-sales support and ongoing maintenance
- Technical questions about inverters, batteries and the 33% rule
- Red flags and paperwork you should always get in writing
- How Solar X Energy applies this checklist in practice
- What happens if the installer finds a problem mid-job
- Why the standard advice undersells how much this checklist matters
- Get a quote that already answers these questions
- Sources
- FAQ
Questions to ask a solar company about their credentials
Anyone can put “licensed and insured” on a van. What you actually need is proof.
Ask for the installer’s Solar Accreditation Australia (SAA) accreditation number and check it’s current, along with Clean Energy Council approval on the equipment they’re proposing. Both are checkable within minutes, and a reliable installer hands the numbers over without hesitation.
- Ask for their SAA and CEC accreditation numbers, then verify both online rather than taking their word for it.
- Check whether they hold NETCC approval, a higher-tier consumer protection standard worth asking about for battery packages specifically.
- Ask how long they’ve traded locally, what their ABN registration date is, and whether they have a physical office you could visit.
- Request two or three references from recent local installs, and confirm whether their own employees or a subcontracted crew will be on your roof.
That last point matters more than most homeowners realise. In-house teams generally give you smoother continuity when something goes wrong under warranty, because there’s one company accountable from sale through to service call.
Site visit and system sizing questions to ask
A quote built from a satellite photo is a guess dressed up as a number. Roof pitch, shading from next door’s gum tree, the condition of your switchboard: none of that shows up on Google Earth, and a proper installer needs to see it in person before pricing anything.
- Insist on a physical site visit covering roof condition, shading throughout the day, panel orientation, existing wiring, and the switchboard.
- Ask exactly how they arrived at the recommended kW size, whether they modelled your actual usage or billing history, and what annual kWh output they expect.
- Clarify their approach to oversizing under the 1.33 rule (commonly called the 33% rule), which caps how much panel capacity can exceed inverter output while keeping full STC eligibility.
Pro Tip: Ask to see projected hourly or daily generation charts rather than just a headline wattage figure. A well-sized, deliberately oversized array often produces meaningfully more usable energy across the day than a “correctly sized” one that clips hard at midday.
If you’re on a tile roof or near the coast, ask specifically how they’ll handle mounting and corrosion risk, both of which change the job significantly.
Component brands, model numbers and warranty terms
A quote that says “6.6kW panels, 5kW inverter” and nothing else tells you almost nothing. You need actual model numbers, because warranty length, degradation rates, and after-sales support vary enormously between brands wearing similar spec sheets.
- Request the exact model numbers and datasheets for the panels, inverter, and battery (if included), plus each component’s manufacturer warranty and performance warranty period.
- Confirm the manufacturers have genuine Australian support, not just an overseas call centre, and get direct contact details for lodging a warranty claim.
- Get the installer’s own installation warranty in writing, including how fast they respond to a fault call and the actual claim process, not just a verbal promise.
Warranty details are one of the areas installers should be upfront about without you having to push. Solarxenergy’s own guide on component warranties breaks down what a fair warranty period looks like across panels, inverters and batteries.
Cost, rebates and payback: what to nail down before signing
Vague pricing is where a lot of homeowners get burned. Every dollar should be itemised on paper before you commit to anything.
- Ask for a fully itemised written quote listing parts, labour, GST, and any extra works like switchboard or meter upgrades. Buyer guidance recommends collecting at least three quotes built this way so you can compare them properly.
- Confirm who actually claims the Small-scale Technology Certificates (STCs) and any state rebate, and whether that discount is already reflected in the price you’re being shown.
- If finance is on the table, ask for the total repayable amount including interest and fees, not just the monthly figure, and check whether finance terms affect your warranty or contract rights.
- Ask for a realistic payback estimate based on your actual usage, not a generic industry average.
The cheapest quote on the table isn’t automatically the best one. Consumer advice consistently flags that a rock-bottom price can hide inferior panels or a rushed install. Solarxenergy’s breakdown of solar installation costs is a useful benchmark for comparing what you’re being offered.
What to expect on installation day
You shouldn’t be finding out what’s happening on the morning the crew turns up. Get the schedule locked in beforehand.
- Ask when the job starts and finishes, how many days it’ll take, and who will physically be on-site each day.
- Clarify who submits the grid connection application and arranges any meter upgrade, and who’s paying for it. Grid connection needs to be finalised before your system can be commissioned.
- Ask how long commissioning and meter registration typically takes after the physical install wraps up.
- Request a written timetable, plus anything you need to do (like being home, or having pets secured) to help the day run smoothly.
After-sales support and ongoing maintenance
A solar system isn’t a set-and-forget purchase. What happens twelve months in matters just as much as what happens on install day.
- Ask whether monitoring is included in the price and how you’ll access your performance data, then check if there’s any ongoing subscription fee attached.
- Clarify their response window for fault calls and whether their own staff or a subcontractor handles service and maintenance.
- Ask about local spare parts availability and whether they offer a scheduled maintenance plan, rather than a purely reactive one.
Technical questions about inverters, batteries and the 33% rule
This is where you separate an installer who genuinely understands your system from one reading off a template.
- Ask why they’ve chosen that specific inverter model, its rated AC output, and its MPPT configuration, and how that pairs with any oversizing on the panel array.
- If a battery is part of the package, ask about its chemistry, where it will be mounted, what fire-safety measures apply, and whether it can participate in a virtual power plant (VPP). Solarxenergy’s battery installation guide covers the safety checks worth raising directly with your installer.
- Ask how your local network’s export limits affect the system size they’re proposing, and confirm any oversizing still sits within STC rules under the 1.33 ratio.
Battery fire safety and mounting location are also worth raising with an electrical engineering lens in mind, particularly around lightning exposure on exposed roofs, a risk area covered well by engineering guidance on PV lightning risk.
Red flags and paperwork you should always get in writing
Some warning signs are obvious once you know to look for them. Others are easy to miss when you’re excited about the savings.
- No accreditation numbers offered, or reluctance to provide them when asked directly.
- No physical site visit before the quote is finalised.
- Vague or verbal-only warranty promises instead of anything written down.
- Handwritten quotes, high-pressure sales tactics, or a push for cash-only payment.
- Deposits requested before you’ve seen an itemised, signed contract.
Insist on an itemised written quote, component datasheets, a signed contract with clear cooling-off terms, accreditation numbers, and the company’s ABN before paying anything. If a site inspection turns up a major roof or network issue, a reasonable installer will offer to terminate and refund your deposit rather than push ahead regardless. If something feels off at any stage, get independent advice or walk away. Solarxenergy’s guide on comparing solar quotes is a useful cross-check against whatever you’re handed.
How Solar X Energy applies this checklist in practice
A locally owned Illawarra provider with a strong reputation focuses on genuine local support rather than a call centre model. The team specialises in tailored solar and battery packages using premium components and stays involved well past installation day through ongoing care and help with electricity retail options.
Every quote from a reputable local installer should hold up against this checklist: accreditation details on request, a genuine site visit, itemised pricing with real component models, and clarity on who’s installing your system. If you’re comparing quotes right now, ask each installer the same questions and see how they measure up.
What happens if the installer finds a problem mid-job
Roofs hide surprises. A switchboard that looked fine from the ground might turn out to need an upgrade once the crew gets up there, or old wiring might not meet current standards. What separates a decent installer from a shonky one is how they handle that moment.
Ask upfront what their policy is if they discover an issue after work has started, things like unexpected asbestos in eaves, rotten roof battens, or a switchboard that can’t safely take the new load. A trustworthy installer stops, explains the problem in plain language, and gives you a revised cost estimate before doing any additional work, not after the invoice arrives. Anything else should be treated as a serious red flag.
Get this in writing before signing: how variations are quoted, whether you’re required to approve extra costs before they proceed, and what your options are if you don’t want to pay for the additional work. Some contracts allow you to cancel without penalty if the variation is substantial. Others lock you in regardless. You want to know which one you’re signing before there’s a hole in your roof.
Ask, too, how they handle weather delays and whether there’s a revised completion date process. A single wet week shouldn’t turn into radio silence for a month. Reasonable installers build a buffer into their timeline and communicate proactively if something shifts, rather than leaving you chasing them for updates.
Why the standard advice undersells how much this checklist matters
Most solar guides treat these questions as a box-ticking exercise: ask about accreditation, tick it, move on. That undersells how much leverage a good question actually gives you. The homeowners who get burned aren’t usually the ones who skipped research entirely. They’re the ones who asked surface-level questions, got a confident-sounding answer, and stopped there.
The order matters too. Credentials first, because nothing else is worth discussing if the installer can’t prove who they are. Then sizing and site suitability, because a beautifully specced system on a poorly assessed roof is still a bad outcome. Components and warranties come before cost, not after, because comparing prices on unlike systems is meaningless.
If you take one thing from this checklist, make it the itemised quote with model numbers. It’s the single document that exposes whether an installer has actually thought through your job or is quoting off a template. Everything else, references, warranty terms, timelines, tends to fall into place once that document is solid.
— Matthew
Get a quote that already answers these questions
This installer offers an alternative to chasing vague verbal promises: every quote comes itemised with actual component models, warranty terms, and a genuine site visit before a number ever reaches paper. Accreditation details and warranty specifics are included upfront in the quote.
That approach suits homeowners who’ve read enough solar horror stories to know exactly what they don’t want: a rushed desktop quote, a mystery inverter brand, or a subcontractor they’ve never met turning up unannounced. The installer’s own staff handle installations locally, and support continues after the panels go up, including assistance with electricity retail options once your system is running.
If you’re ready to test a real quote against everything covered here, get a free solar quote or browse current solar and battery packages to see what an itemised, contract-ready offer actually looks like.
Sources
- Solar installation: How to find the best installer for panels and batteries
- Energy
- Small-scale technology certificates (STCs) | CER
FAQ
What is the 33% rule for solar panels?
It refers to the 1.33 oversizing ratio set for STC eligibility, meaning panel capacity can exceed inverter output by up to 33% while the system still qualifies for the standard rebate.
What are the most important questions to ask a solar installer?
Ask about their SAA and CEC accreditation, whether they’ve done a physical site visit, who performs the installation, and for an itemised quote naming exact component models and warranty terms.
What is the “20% rule” for solar mentioned online?
If you’ve seen it referenced, ask the installer directly what specific figure or standard they’re referring to before assuming it applies to your system.
What questions should I ask when choosing a solar company?
Ask about accreditation numbers, how long they’ve operated locally, whether they use their own installers or subcontractors, and for references from recent local jobs, alongside a fully itemised written quote.
How many quotes should I get before choosing a solar installer?
Industry guidance recommends collecting at least three written quotes so you can properly compare component brands, pricing, and installation warranty terms side by side.
