A real consultant should answer all seven of these without checking notes. A cowboy will deflect, change the subject, or "get back to you on that." Listen for the difference.
Australians spend more time researching a $400 dishwasher than they do a $15,000 solar install. Partly because the industry is opaque, partly because the salesperson is the only "expert" most people meet. So here's a list you can take into any solar conversation — over the phone, at a sales meeting, or on a doorstep. If the installer flinches at any of these, the conversation has told you what you need to know.
01"What's my actual roof capacity, after shading?"
A real installer answers this with a specific number — "your north-facing roof will fit ~7.8kW after we account for the chimney and the morning shade from the next-door gum" — and shows you a satellite tracing or shading model. A cowboy answers "yeah, we'll fit 6.6kW on there, no worries" without having looked at the roof.
The reason this question matters: most quotes are not sized to the roof. They're sized to the salesperson's default kit. If you don't ask, you don't find out you could have fit 10kW until the next homeowner upgrades.
02"Why this inverter brand, specifically?"
You're asking the installer to defend a hardware choice. The answer should mention serviceability ("Sungrow has Australian warehousing in Sydney and Brisbane, so a swap takes 5–7 days"), reliability data, or the inverter's match with your panel string design.
The wrong answers, in order of severity:
- "It's what we use." (No reasoning.)
- "Same as the panels' warranty period." (They're not equivalent terms.)
- "It's the cheapest one that works." (At least it's honest.)
- A brand name you've never heard of, with no Australian service centre. (Walk away.)
03"If your retailer folds in three years, who handles my warranty claim?"
This is the single most important question and the one nearly all retailers answer badly. Solar Citizens estimates that roughly 30% of Australian residential solar retailers from 2018–2020 are no longer trading. Your installer-side warranty is only as good as the company offering it.
A good installer answers with specifics: "Our workmanship warranty is underwritten by [name], and the panel + inverter warranties are direct manufacturer warranties that survive us — here's the manufacturer's Australian service-claim portal." A cowboy mumbles about "manufacturer warranty" and changes the topic.
Solar warranties are worth exactly as much as the company answering the phone.
04"What's the export limit on my local network, and how did you size around it?"
Every Australian DNSP (the network distributor — Ausgrid, Endeavour, Energex, SA Power, Western Power, Essential, Powercor, AusNet, Citipower, Jemena, TasNetworks) has its own export rules and they change. Some allow 10kW export per phase; some allow 1.5kW; some are dynamic with smart inverters.
If your installer hasn't checked your network's specific rules and designed around them, you might find half your generation curtailed at the meter. A consultant will name your DNSP and tell you the export limit before quoting. A cowboy will sell you 13kW of panels on a single-phase 5kW export and let you discover the problem after switch-on.
05"What's the panel degradation curve, and what's covered at year 12?"
Tier-1 panels (Trina, Jinko, LONGi, REC, Q CELLS, Risen, JA Solar, Canadian Solar) typically warranty 25 years of performance, with output declining no more than ~0.4% per year. Premium tier-1 (SunPower, REC Alpha) often warranty better. Budget panels — and panels that look tier-1 on paper but came in via grey-channel imports — degrade faster and the warranty is harder to claim.
Ask the installer the warranty's degradation guarantee number, then ask what's actually covered if your panels under-perform. A real answer references the manufacturer's claim process. A cowboy answer is "they're guaranteed for 25 years" and a hand-wave.
06"What happens if the install fails its DNSP inspection?"
After install, an inspector (either DNSP-appointed or independent depending on the state) checks the work. Failure is more common than people think — DC isolators in the wrong place, conduits run on the surface of the roof, undersized cabling, paperwork mistakes. The question is who pays to fix it.
A reputable installer answers: "We do, including the truck roll. The work isn't complete until it passes inspection, so we wear the rectification cost." A cowboy answers vaguely about "site conditions" or wants to charge you a re-attendance fee. Get this answer in writing on the quote.
07"Show me three jobs you've done on a roof like mine."
Not testimonials. Not five-star reviews. Photos with addresses (suburb level is fine), system sizes, and dates. A real installer can pull these up. A cowboy installer either can't or shows you sub-contractors' work that wasn't theirs.
The reason this matters: solar installs vary wildly by roof type — tile, Colorbond, Klip-Lok, slate, terracotta. The brackets, flashings, and rail systems are different. Someone who's done 200 installs on Klip-Lok roofs is meaningfully better than someone who's done 200 installs total. Specific experience beats general experience.
The way to use this list. Don't fire all seven at once — you'll sound like a lawyer. Pick three you genuinely want answers to, ask them naturally during the conversation, and listen to how confident the responses sound. The right installer will get noticeably more specific. The wrong one will get noticeably more nervous.
08The bonus question: "What would you tell me to ask any other quote?"
Asked of a salesperson, this is uncomfortable — they're inviting you to scrutinise their competitors. A confident installer will give you two or three specific things ("ask them what inverter brand, ask them whether they're doing the install themselves or sub-contracting"). They'll do this because they know they win on the spec, not on the pitch.
A cowboy answers "doesn't really matter who you go with, we all do the same thing" — which is the loudest possible signal that they don't want you comparing.
09The honest summary
Most homeowners don't have the time, the technical background, or the appetite for a fight to run a serious diligence on a solar installer. That's exactly why an unbiased consultant exists. We've already asked these seven questions of every retailer on our panel — and we keep asking them, every quarter, because the answers change as companies expand, contract, or quietly start cutting corners.
The version of solar buying where you sit through three kitchen-table pitches and try to remember which one mentioned which inverter is the version that produces the most regret. Skip it. Get someone who's done this thousands of times to walk you through it.