10 Questions to Ask a Solar Installer Before You Sign Anything

Before signing any solar contract in NSW, ask your installer these 10 questions. A trustworthy company will answer every one clearly and in writing — a dodgy one will dodge, deflect, or rush you. In the Illawarra, where hundreds of door-knockers and phone-room resellers compete with genuine local installers, these questions are the fastest way to separate the professionals from the pretenders.

1. Are you CEC-accredited, and who will physically install my system?

Clean Energy Council (CEC) accreditation is the minimum legal requirement to claim the federal STC rebate. But there's a catch many buyers miss: the salesperson doesn't need to be accredited — only the designer and the installer on the roof. Ask for the name and CEC accreditation number of the specific person who will design your system and the one who will install it.

At Coastal Solar Co., every install is done by our own CEC-accredited electricians — we don't subcontract to a rotating cast of day-labour crews. If an installer can't tell you who's actually on your roof until the day of install, that's a red flag.

2. What panel brand and tier are you quoting?

"Tier 1" is a financial stability rating from Bloomberg — not a quality rating. A Tier 1 manufacturer simply means the company is considered bankable by large project financiers. It tells you nothing about panel efficiency or degradation rates.

Ask for the exact make and model. For Illawarra homes, we typically recommend well-established brands like REC, Jinko Tiger Neo, Trina Vertex S, LONGi, or Q CELLS. Then cross-check the model on the CEC approved products list. If the model isn't listed, you can't claim your STC rebate.

What about "Tier 1" panels you've never heard of?

Some retailers quote extremely cheap Tier 1 brands that are technically on the Bloomberg list but have tiny Australian service networks. If that brand folds or leaves the market — as several have over the last five years — your warranty is worthless. Stick with manufacturers that have a documented Australian support presence.

3. What inverter are you using, and is it single-phase or three-phase?

The inverter is the single most failure-prone component in a solar system. Cheap string inverters from unknown brands routinely fail at year 5–7. Better options for NSW conditions include Fronius Primo/Symo, SMA Sunny Boy/Tripower, Sungrow, and GoodWe — all with solid local service networks.

Also confirm whether your home has single-phase or three-phase power. Many larger Illawarra homes (especially post-2010 builds in Shellharbour and Albion Park) have three-phase, and if you're installing 10kW or more, you'll almost always want a three-phase inverter to balance export and avoid voltage-rise issues on the street.

4. What are the separate warranties — and who honours them?

There are three warranties you need to understand:

• Panel product warranty — typically 12–25 years against defects. Honoured by the panel manufacturer.
• Panel performance warranty — 25–30 years guaranteeing output doesn't drop below a certain percentage. Also from the manufacturer.
• Inverter warranty — usually 5–10 years standard, extendable to 10–15.
• Installer workmanship warranty — this is the big one. Should be at least 5 years, ideally 10, covering labour for any defect in how the system was fitted.

Ask: "If my inverter fails in year 8, who comes out, who pays for the truck, and who pays for the labour to swap it?" A good installer has a clear answer. A dodgy one waves vaguely at "the manufacturer".

5. How was the system sized — and can I see the shading/production report?

Any competent installer uses software like PV*SOL, Aurora, or OpenSolar to model your exact roof in 3D, accounting for panel orientation, tilt, shading from trees or neighbouring buildings, and Illawarra-specific irradiance data. Ask to see the generation estimate in kWh per year, month-by-month.

If the quote is just "6.6kW produces 9,500 kWh/year" without a tailored report, the installer hasn't done proper design work — they've just applied a rule of thumb. That matters on sites with partial shading (common in leafy parts of Wollongong, Thirroul and Gerringong).

6. What happens with my STC rebate — is it applied at point of sale?

The Small-scale Technology Certificate (STC) rebate is worth roughly $2,800–$3,800 on a 6.6kW system in 2026. Reputable installers apply this as a point-of-sale discount — you never see or handle the certificates.

Watch for two scams: (1) Installers who quote the "before STC" price and then surprise you with fees, and (2) installers who promise an "extra rebate" that doesn't exist. The only federal rebate for residential rooftop solar in NSW in 2026 is the STC scheme and the Cheaper Home Batteries Program (for batteries only).

Use our free Solar Savings Calculator to see your personalised payback period.

7. Are you handling the Endeavour Energy / Essential Energy connection?

Grid connection approval is required for every new solar install. In the Illawarra, that means Endeavour Energy for Wollongong, Shellharbour, Kiama and most of Shoalhaven; Essential Energy covers further south and inland. The application needs to be submitted before install, and the installer must commission the system on the day and submit the CES (Certificate of Electrical Safety) afterwards.

Ask: "Do you submit the pre-approval and the CES, or do I need to organise it?" A proper installer handles everything end-to-end. You should never be chasing forms with your distributor.

8. Will my roof need any structural work — and is that included?

Older Illawarra homes — particularly 1970s-era brick-and-tile builds in Corrimal, Fairy Meadow and Berkeley — sometimes have tile conditions that require replacement tiles, tile underlay repair, or even minor rafter reinforcement. A good installer will flag this during the site assessment and put any remediation work in the quote.

A cheap quote that omits this work means you'll get a bill shock on install day, or worse, a system installed on a roof that leaks afterwards.

9. What's your monitoring setup — and is it free forever?

Every modern inverter (Fronius, SMA, Sungrow, GoodWe, etc.) comes with a free smartphone app showing real-time generation and historical data. You should never have to pay a monthly fee for basic monitoring.

If an installer is pushing a "premium monitoring subscription" at $10–$20/month, ask why — often it's because the system uses a no-name inverter without proper manufacturer monitoring, and the reseller has bolted on a third-party service.

10. How long have you been installing in the Illawarra, and can I see local references?

Solar installers come and go. The national one-star cowboys often run brand names that only exist for 18 months before re-registering under a new ABN when the warranty claims start piling up.

Ask for three local references — ideally installs within 10km of your home. A genuine local installer will happily provide them. Also check their Google reviews, ProductReview.com.au listing, and how long their ABN has been active (via ABN Lookup). If the company is less than 3 years old, be extra cautious.

Frequently Asked Questions

How do I spot a dodgy solar quote?

The classic warning signs: high-pressure "today only" pricing, refusal to itemise components by make and model, unrealistically cheap headline prices (under $3,500 for 6.6kW typically means corners are being cut somewhere), sub-5-year workmanship warranties, and salespeople who can't tell you what inverter they're using without phoning the office.

Should I always get three quotes?

Three is a reasonable minimum. But don't just compare headline prices — compare what's actually in the quote. A $6,500 quote with Tier 1 panels, a Fronius inverter and a 10-year workmanship warranty is often cheaper over 15 years than a $5,200 quote with an unknown inverter and 2-year workmanship cover.

What's the minimum workmanship warranty I should accept?

Five years is the bare minimum in NSW. Ten years is the benchmark for quality installers. Anything less — or anything that only covers "manufacturing defect" but not labour — is a sign the installer doesn't back their own work.

Do I need council approval for solar in Wollongong or Shoalhaven?

For most homes, no — rooftop solar is classified as "exempt development" under the NSW State Environmental Planning Policy, provided it doesn't protrude more than 500mm above the roof plane and you're not in a heritage area. Wollongong City Council and Shoalhaven City Council follow the state rules. Your installer should confirm this during their site assessment.

What should a good quote document include?

Written, itemised quote showing: exact panel make/model/count, inverter make/model, mounting system, cabling method, installation date, grid connection handling, STC rebate value shown as a line item, all three warranties with lengths, total GST-inclusive price, and the workmanship warranty terms. If your quote is a one-page PDF with "6.6kW System — $5,990" and nothing else, demand a full spec sheet before signing.

Ready to get your personalised quote? Contact our CEC-accredited team — we'll call you back within 5 minutes.