Going solar is one of the smartest financial decisions an Australian homeowner can make but only when it’s done right. The wrong system size, a poor-quality installer, or a misunderstanding about how warranties and rebates work can turn a great investment into a costly disappointment.
The good news is that a few well-placed questions before you sign anything will tell you almost everything you need to know about whether a solar company is worth trusting. Here are the seven questions every homeowner should ask any solar installer before agreeing to a quote and what the right answers look like.
1. Are You CEC-Accredited and Is Your Installation Team In-House?
This is the single most important question you can ask and the answer tells you a lot about the company you’re dealing with.
What to look for: The Clean Energy Council (CEC) is Australia’s peak body for the renewable energy industry. CEC-accredited installers have completed approved training, are required to follow the CEC’s installation guidelines, and must use products from the CEC-approved product list. Only CEC-accredited installations are eligible for the federal government’s Small-Scale Technology Certificates (STCs) which means only CEC-accredited installations qualify for the upfront rebate that reduces your system cost.
Beyond accreditation, ask whether the people physically installing your system are employed directly by the company or subcontracted out. Many solar companies operate as brokers they take your deposit, then hand your job off to a third-party installer you’ve never met and have no relationship with. This matters enormously when something goes wrong and you need warranty support.
A reputable company will have its own licensed, insured, in-house installation team and will be happy to confirm this upfront. Solar National’s installations are carried out by our own accredited team not subcontractors which is one of the reasons we back every job with a 10-year installation warranty.
2. What Brands of Panels, Inverters, and Batteries Are You Quoting?
Not all solar products are created equal, and the brand names on your quote sheet matter — a lot. A cheap system using off-brand panels and a no-name inverter may look attractive on day one but will likely underperform, degrade faster, and prove difficult to service within a few years.
What to look for: Ask specifically which brand and model of solar panels, inverter, and battery (if applicable) are included in the quote, and then research them independently before accepting. Look for:
- Panels: Tier 1 status from Bloomberg NEF, a minimum 25-year performance warranty, and an efficiency rating above 20%
- Inverters: Brands with established Australian service networks and a minimum 5–10 year warranty. Browse Solar National’s range of solar inverters to see the brands our team recommends and installs
- Batteries: Recognised brands with Australian safety certification. Popular, proven options include the Tesla Powerwall 3, BYD Solar Battery, Sungrow Solar Battery, SAJ Solar Battery, and Sigenergy Battery
A good installer should be able to clearly justify every product on the quote — not just default to whatever has the highest margin. If they struggle to explain why they’ve chosen a particular panel or inverter, that’s a red flag.
3. Is This the Right System Size for My Home?
A reputable installer should ask about your electricity consumption — ideally request a copy of your bill before recommending a system size. If someone is quoting you a system without ever asking how much power you use, they are not designing a system around your needs.
What to look for: The right system size is calculated from your actual daily energy usage in kilowatt-hours (kWh), your location’s average peak sun hours, and your roof’s orientation and available space. In Sydney and greater NSW, most households fall between a 6.6 kW and 13.2 kW system but the right size for your home depends on your specific consumption pattern.
If you’ve already done some research, our guide to what size solar system you need walks through the exact calculation so you can sense-check whatever a company is quoting you. A system that looks unusually small or unusually large relative to your usage is worth questioning before you commit.
Also ask whether the quoted system accounts for any planned changes in your energy use such as adding an EV charger, switching from gas to electric appliances, or installing solar battery storage in the future. A good installer will design with your energy future in mind, not just your energy present.
4. What Warranties Come With the System — and Who Backs Them?
There are typically three separate warranties on a solar installation, and most homeowners don’t realise they’re different until they need to make a claim:
- Panel performance warranty — guarantees the panels will still produce a minimum percentage of their rated output (usually 80–90%) after 25 years
- Panel product warranty — covers manufacturing defects, typically 10–15 years
- Inverter warranty — covers the inverter unit, typically 5–10 years (some brands offer extensions)
- Installation (workmanship) warranty — covers the quality of the physical installation, including mounting, wiring, and weatherproofing
What to look for: Ask each of these questions explicitly, because a quote might advertise a “25-year warranty” when they actually mean only the panel performance warranty. The installation warranty is the one most directly tied to the installer — and a company that offers only a 1–2 year workmanship warranty is signalling limited confidence in the longevity of their own work.
Equally important: who actually backs the warranty if something goes wrong? If the company you bought from has closed down, a manufacturer warranty is only useful if the manufacturer has an Australian service network. Ask how warranty claims are handled in practice before you sign.
Before committing, it’s also worth reading about solar battery safety standards in Australia — particularly if your quote includes battery storage, as recent changes to installation compliance requirements affect what a correctly installed system looks like.
5. What Government Rebates and Incentives Are Included in This Quote?
Australia’s solar rebate landscape is genuinely generous but it’s also frequently misrepresented. Some installers advertise a system price before rebates to make it look cheaper, others inflate the pre-rebate price to make the discount look bigger, and some simply get the rebate calculation wrong.
What to look for: The main federal incentive is the Small-Scale Technology Certificate (STC) scheme under the Small-Scale Renewable Energy Scheme. Your installer calculates your STCs based on system size, location, and the number of years remaining in the scheme, then applies this as an upfront discount to your quote. Ask for the STC calculation to be shown to you explicitly, so you understand what you’re actually paying.
If you’re adding battery storage, ask specifically about the federal government solar battery rebate and whether your system and household are eligible. Recent changes to the Cheaper Home Batteries Program from May 2026 have expanded eligibility significantly — a good installer will know the current rules and apply them accurately.
Also ask whether there are any state-level rebates or programs available in your area. Eligibility varies by state, household income, and system type, and an informed installer should be across all of it.
6. How Will the System Be Monitored and What Happens If Output Drops?
A solar system that’s generating less than it should is costing you money every single day and without monitoring in place, most homeowners have no way of knowing. Studies suggest a significant portion of solar systems in Australia are underperforming at any given time, often due to faults, shading, or degraded components the owner doesn’t know about.
What to look for: Ask whether the system comes with a monitoring platform most modern inverters include Wi-Fi-connected monitoring that you can access via a smartphone app. More importantly, ask what happens if the system’s output drops: does the installer proactively monitor output and contact you, or is it entirely on you to notice?
The best installers will set up monitoring during commissioning, walk you through how to read your system’s output data, and explain what normal vs abnormal performance looks like. Ask for the monitoring app to be demonstrated before the installer leaves your property.
If you’re considering battery storage, ask how the battery’s state of charge and charge/discharge cycles are monitored too. Understanding the difference between AC-coupled and DC-coupled battery systems is useful context here the two setups have different monitoring architectures, and your installer should be able to explain how yours will work in practice.
7. What Are the Finance and Payment Options?
Solar is a significant upfront investment typically $5,000–$15,000+ depending on system size and whether you’re adding battery storage. Understanding your payment options before agreeing to a quote ensures there are no surprises and helps you compare the true cost across competing quotes.
What to look for: Ask specifically:
- Is a deposit required, and how much? Be cautious of any company asking for a large deposit before installation — 10–20% is standard; 50%+ upfront is a red flag
- Are there interest-free or low-interest finance options? Solar National offers flexible solar finance options and Handypay solar finance to spread the cost without a large lump-sum payment
- Is the quote locked in, or can prices change before installation? Supply chain issues have caused price fluctuations in the industry confirm in writing whether your quoted price is fixed
- What is the payment schedule? Reputable companies typically require full payment only on or after completion, not before the work begins
- Are there any ongoing costs? Some battery systems or monitoring platforms carry ongoing software subscription fees ask about these explicitly so you can factor them into your comparison
If the answer to the finance question is “we only accept cash or bank transfer in full before installation,” that’s worth treating as a warning sign. Established, confident companies offer transparent payment terms because they know they’ll deliver on the job.
One Final Thing: Get At Least Three Quotes
No single quote gives you the context to know whether you’re being offered fair value. Getting three quotes from different installers ideally with itemised breakdowns of panels, inverters, labour, and rebates gives you a real basis for comparison.
What you’re comparing isn’t just price. You’re comparing product quality, warranty terms, company reputation, and the installer’s ability to answer all seven of the questions above clearly and confidently. The cheapest quote is often cheap for a reason; the most expensive isn’t automatically the best. The right quote is the one that delivers lasting value.
Whether you’re just starting your research or ready to move forward, Solar National’s team of CEC-accredited experts services Sydney, Chatswood, Penrith, the Central Coast, and surrounding NSW regions. We’ll walk you through every one of these questions and give you a free, no-obligation quote based on your actual energy usage and roof layout.
