Australia has well over 4 million rooftop solar systems installed. The industry has learned a lot from what goes wrong. Here are the seven most common mistakes — and how to avoid each one.
Mistake 1: Buying on Price Alone
The cheapest quote is usually cheap for a reason — lower-grade panels, a no-name inverter, an inexperienced installer, or corners cut on the installation. In an industry where a bad install can cause roof leaks, fire risk, or voided warranties, the lowest price is a red flag rather than a win.
The right approach: filter on accreditation and reviews first, then compare price on equivalent-spec systems.
Mistake 2: Getting Only One Quote
You don't know what fair value looks like until you've seen at least three quotes. One quote gives you a price with no context. Three quotes give you a market, component quality benchmarks, and negotiating leverage.
Mistake 3: Sizing for Today, Not Tomorrow
Sizing a system purely for your current consumption is fine — if your life is going to stay exactly the same. But if there's any chance of an EV in the next 5 years, a heat pump hot water upgrade, or more people moving in, you want a system sized with some headroom.
The marginal cost of going from 6.6kW to 8.5kW at install is usually $1,000–$1,500 — far less than the cost of retrofitting larger capacity later.
Mistake 4: Ignoring the Inverter
The inverter is the most likely component to fail within the system's life. Yet many buyers spend all their attention on panel brand and give no thought to inverter quality or warranty.
Stick with established brands: Fronius, SMA, SolarEdge, Sungrow, Enphase. Avoid no-name inverters. Ask specifically about the warranty length (5 years standard; 10+ years available on premium brands).
Mistake 5: Forgetting About Battery Readiness
You may not want a battery today — but if you want one in 3 years, the inverter you choose now matters. A standard string inverter will require an AC-coupled battery later (which is fine but slightly less efficient and more expensive). A hybrid inverter is designed for this from day one.
If there's any chance of adding a battery, tell your installer and get a hybrid inverter upfront.
Mistake 6: Not Checking for Shading
Shade is the enemy of solar performance. A chimney, a dormer window, a neighbouring property's extension, a tree that's grown since you moved in — all of these can significantly reduce output.
Ask every installer to do a shading analysis, not just a satellite imagery review. If shading is present, discuss whether microinverters or DC optimisers would improve performance enough to justify the cost.
Mistake 7: Choosing an Installer Who Won't Be Around for the Warranty
The workmanship warranty is only as good as the company that issued it. If your installer closes in year 4, your 10-year workmanship warranty is worth nothing.
Check: how long has the company been operating? Do they have a physical address? Are they responsive when you call with questions before you've signed? Longevity, responsiveness, and a verifiable local presence are the best indicators of an installer who'll still be around when you need them.
The Bottom Line
Every one of these mistakes is avoidable with a bit of upfront research. Take your time, get multiple quotes, verify everything in writing, and start with your actual consumption data.
Upload your electricity bill to GridBeater for an independent savings estimate — it gives you a baseline before you talk to any installer, so you can spot inflated savings projections immediately.
Start with the real numbers → Upload your bill free at GridBeater