Energy

What Should You Ask a Solar Installer Before You Sign Anything?

Published 3 September 2026 · Osborn Energy Advisory

Most people go into a solar or battery quote knowing what they want — lower bills, backup power, a system that's actually worth the outlay — but not knowing what to ask to get there. The installer is the one selling the system, so the questions you ask, and how closely you listen to the answers, do a lot of the work of protecting you.

Here's what's worth asking before you sign anything, and why each one matters.

Ten questions worth asking

What size system are you recommending, and why that size? Ask them to connect the system size back to your actual usage — not a standard "most popular" package. A vague answer here is worth noticing.
What brand and tier are the panels and inverter, and why that tier? Every installer sells a range from budget to premium. Ask them to explain where this quote sits and what you're trading off at that tier — not just the brand name. If a battery's part of the quote, ask what chemistry it uses too — most current-generation home batteries are LFP (lithium iron phosphate), valued for safety and a longer cycle life, so it's worth asking why if something else is being proposed.
What's the warranty on the panels, the inverter, and the battery — and who honours it? Manufacturer warranties and installer workmanship warranties are different things. Ask both, and ask what happens if the installer isn't trading in five years' time.
Are you CEC accredited, and who's physically doing the install? Clean Energy Council accreditation matters for rebates and safety standards. Subcontracted installs aren't automatically a problem, but you're entitled to know who's actually on your roof.
What's excluded from this price? Switchboard upgrades, scaffolding, tricky roof access, extra cabling — these show up as "extras" after the fact more often than they should. Ask what's in the number and what isn't.
How did you calculate my payback period? If they give you a figure, ask what it's based on — your usage pattern, current feed-in tariff, how much of your generation you actually use versus export, and your actual export limit under SA Power Networks' Flexible Exports scheme. A quote that assumes you can export freely, without checking what your connection is actually allowed to send back to the grid, can overstate what you'll get paid. A payback figure with no assumptions behind it isn't one you can rely on.
What happens if the system underperforms? Ask what the actual process looks like if output doesn't match what was promised — not just "it's covered by warranty."
Can I see a recent, real installation you've done — not a stock photo? A local job, ideally nearby, tells you more than a brochure.
Is this quote specific to my roof, or a generic package with my address on it? Shading, orientation, and roof condition change what a system should look like. If the quote reads the same as every other quote you've had, that's a sign it wasn't built around your property.
Why should I choose this system over the other quotes I've had? A good installer can answer this directly, comparing on substance — not just price.

Most people don't get past two or three of these before signing. It's not because people are careless — it's because installers are, understandably, selling. Their job is to close the deal, not to slow you down with the questions that might complicate it.

The Adelaide angle

Working across Adelaide, Adelaide metro and the Adelaide Hills, I see the same pattern regardless of suburb: the quote that answers these questions clearly, unprompted, is usually the one worth taking seriously. The quote that gets vaguer the more specific your questions get is the one worth pausing on — wherever in South Australia you're based.

Where a second opinion fits in

That gap — between what a quote says and what it should be able to answer — is exactly what a second opinion closes. I'm a sales partner for one installer, and I'll always tell you that before it matters. If you've already got a quote in hand and want someone to check it against these questions properly, that's what a Solar Quote Review is for. If you're still working out what you need before you're even at the quote stage, a Clarity Session is the better starting point.

Got a question about your own situation before you book anything? Email jarrod@jarrodosborn.au — I read every one.

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Jarrod Osborn has spent 9+ years in the South Australian solar and battery industry. He's also a sales partner for an installer, and that's always disclosed upfront.