Everyone loves a bargain, and with power bills where they are, it makes sense to shop around for solar and batteries. But a solar system sits on your roof for 20 years or more, and a home battery lives on the side of your house. The quote that looks cheapest on the day is not always the one that costs the least over that time. Here's what we see when corners get cut, and how to protect yourself before you sign.

Accreditation is not optional

In Australia, the person who designs and installs your system should be accredited. Since 2024 that accreditation is managed by Solar Accreditation Australia (SAA). Ask to see the installer's accreditation number. Battery installs need a separate battery endorsement on top of the grid connect accreditation.

This matters for two reasons. First, accreditation means the installer has been trained in the Australian Standards that apply to rooftop solar and batteries, including AS/NZS 5033 for the solar array and AS/NZS 5139 for battery installs. Second, it is a condition of the federal rebate. Small scale technology certificates, or STCs, can only be created when an accredited person designs and installs the system using approved products. If those boxes aren't ticked, the rebate can be clawed back, and the discount you were promised may not be real.

You can check any installer's accreditation yourself on the SAA website. It takes a minute.

Approved products, not mystery boxes

Australia keeps approved product lists for solar panels, inverters and batteries. Products on these lists have been tested against the relevant Australian and international standards. Products that aren't listed are not eligible for STCs, and an inverter that isn't approved can't legally be connected to the grid in Australia.

Cheap quotes often hide their savings in the hardware. A no name panel or a budget inverter can look fine on a spec sheet, but quality varies widely, and the inverter is the part of a solar system most likely to fail. An undersized inverter, or one pushed hard on hot Sydney afternoons, can clip your production and wear out early. Ask for the exact brand and model of every major component, in writing, and check them against the approved lists.

Subcontracted labour you never meet

Plenty of low cost operators sell the system and then hand the install to whoever is available that week. Sometimes those crews are excellent. Sometimes they aren't licensed electricians at all, or the accredited person whose name goes on the paperwork never sets foot on your roof.

In NSW, electrical wiring work must be done by a licensed electrician, and the rebate rules require the accredited installer to be on site for key parts of the job. When the person who signs the paperwork and the person who does the work are different people, things fall through the cracks. Ask who will actually be on your roof, and whether they work for the company or are subcontracted.

Rooftop fire risks and DC isolators

Solar panels produce DC electricity, and DC faults behave differently to the AC power in the rest of your house. Fire and Rescue NSW has publicly warned about solar panel related fires, and many of them trace back to rooftop DC isolators. Water getting into a poorly sealed isolator, or a cheap isolator failing in the heat, is a known problem.

Good installers use quality, correctly rated components, fit proper shrouds, seal every penetration and follow the current standards for where isolators go and how they're mounted. These are small details that take a little extra time and cost a little more. They're also the details that a rushed, low margin install is most tempted to skip.

Cable management you can't see

The parts of an install you'll never look at matter just as much as the panels. Cables lying loose on a roof, rubbing on sharp edges or baking in the sun without UV rated conduit will degrade over time. Connectors from different manufacturers mixed together can overheat. Water ingress, rodent damage and loose terminations are all common findings when systems are inspected after a fault.

Ask to see photos of a past install from the roof, not just the street. Neat, clipped, protected cable runs are a good sign that the rest of the job was done with care.

Warranties that disappear with the company

A 25 year panel warranty sounds reassuring, but a warranty is only as good as the business standing behind it. The solar industry has seen a number of companies close down and reopen under a new name, sometimes called phoenix companies. When that happens, the installation workmanship warranty usually goes with the old business, and customers are left chasing overseas manufacturers on their own.

Warranties can also be voided by the install itself. Most manufacturers require their products to be installed to their instructions and to Australian Standards, by accredited people. Incorrect mounting, unapproved rail or clamps, or poor ventilation around an inverter or battery can give a manufacturer grounds to refuse a claim.

Look for a business with a real local address, a track record you can check, and a clear workmanship warranty in writing.

Questions to ask before you sign

Bring this list to every quote. A good installer will be happy to answer all of it.

* Is the designer and installer SAA accredited, and do they hold battery endorsement if a battery is included? * Who will actually do the install? Are they employees or subcontractors, and is a licensed electrician on site? * What is the exact brand and model of the panels, inverter and battery, and are they on the Australian approved product lists? * How was the inverter sized against the panels, and why? * What DC isolators and connectors will you use, and how will cables be protected on the roof? * How much is the STC rebate in this quote, and is the system eligible? * What workmanship warranty do you offer, how long has your business been operating, and who do I call if something goes wrong? * Can I see photos or speak to a customer from a recent install near me? * Will you register the system with my network and handle the paperwork for grid connection?

Cheaper today, dearer tomorrow

A low upfront price is easy to compare. Production losses, early inverter failure, call out fees and voided warranties are harder to see on a quote, but they show up eventually. The best value system is one that is designed for your roof, built with approved products, installed by accredited people who work for the business, and backed by a company that will still be here when you need it.

That's how we've always worked at Sungen. Our own team designs and installs every system across Sydney and NSW, and we stay in touch long after the install. If you'd like a second opinion on a quote you already have, or a fresh design for your home, we're happy to help.

Lock in your price. Book now.

The real cost of a cheap solar or battery installer in Sydney