How to Compare Two Very Different Home Energy Quotes
When two solar or battery quotes differ by a large amount, the price difference often reflects different assumptions about what the job requires, different components, and different things included in scope. The comparison framework below makes those assumptions visible so you can make a like-for-like judgement.
- Two quotes for the same job type that differ sharply often have scope differences — one includes switchboard upgrade or extended cable run that the other excluded.
- Convert both to a scope-normalised comparison — list what each quote includes and exclude items not in both before comparing prices.
- Component quality affects the comparison — a cheap 6kW system with a tier-3 panel is not the same product as a 6kW system with a tier-1 panel, even if the kW figure is identical.
- Warranty and installer longevity are part of the price — a stronger written workmanship warranty from a long-running company may be worth more than the same headline term from a new operator.
Step 1: Build the scope table
Before comparing prices, list every item from both quotes in a table. Items present in one quote but not the other are scope differences — they explain most of the price gap.
Example scope table for a solar + battery quote:
| Item | Quote A ($14,500) | Quote B ($11,200) |
|---|---|---|
| Panel quantity and brand | 24 × Tier-1 brand (6.6kW) | 24 × Generic (6.6kW) |
| Inverter brand and warranty | 5kW Fronius (10yr warranty) | 5kW generic brand (2yr warranty) |
| Battery brand and usable kWh | 10kWh LFP (named brand) | 10kWh (brand unlisted in quote) |
| Switchboard upgrade | Included (new MSB required) | Not included — "existing board assumed OK" |
| Monitoring hardware | Included | Not included |
| Cable run | Up to 20m included | Up to 10m included |
| Workmanship warranty | 5 years | 2 years |
| Permit and grid connection | Included | Not included — "may apply" |
In this illustrative example, Quote B is cheaper on paper. But the missing switchboard upgrade, permit/connection handling and shorter inverter warranty all need to be priced before calling Quote A expensive.
Step 2: Normalise the comparison
After identifying scope gaps:
1. Ask the Quote B installer: "If I add switchboard upgrade, extended cable run, monitoring, and permit — what is the total?"
2. Get that in writing.
3. Add it to Quote B's price for the normalised comparison.
You may also ask Quote A: "If I remove monitoring — what is the saving?" to close the gap from the other direction.
The goal is a like-for-like total: both quotes covering exactly the same scope, at which point the remaining price difference comes from component quality and installer margin.
Step 3: Compare components — not just specifications
Two quotes both specifying "6.6kW system with 10kWh battery" can still use very different components.
For panels:
- Tier-1 classification (Bloomberg New Energy Finance list) vs generic
- Panel efficiency (affects performance on overcast days and limited roof space)
- Product warranty vs performance warranty — both should be present, and the current warranty documents should state the years and degradation terms
For inverters:
- Brand and Australian service network (check whether the brand has an Australian warranty contact)
- Warranty years (5 vs 10 years)
- Smart monitoring capability (for future solar-aware appliance scheduling)
For batteries:
- Usable kWh (not gross) — confirmed in writing
- LFP (lithium iron phosphate) vs NMC (nickel manganese cobalt) chemistry — LFP generally has longer cycle life and better thermal safety characteristics
- Continuous power output (kW) — affects what loads it can run during a blackout
- Australian Standards compliance (AS/NZS 5139 for battery siting)
Step 4: Assess installer longevity
A solar or battery installation is a long-life household asset. The installer providing the workmanship warranty needs to still be contactable for that warranty to mean anything.
Practical checks:
- ABN registration date (abn.business.gov.au) — how long has the company traded?
- Google reviews count and age distribution — a company with 200 reviews over 5 years is more established than one with 50 reviews in 6 months
- Physical address vs P.O. Box — some fly-by-night operators have no fixed premises
- SAA accreditation status and history where available — confirm the individual's current accreditation, and remember this is separate from the state electrical licence
A modest premium for a long-running, well-documented installer may be reasonable once the scope, components, warranty and after-sales support are genuinely comparable.
When two quotes look very different, build a scope table before comparing prices. Identify what is in one quote but not the other, price the gap, and create a normalised total for each. After normalising scope, compare component quality and installer longevity. The cheaper quote often becomes competitive with the more expensive one — or the gap narrows enough to make the decision on non-price factors.
Browse solar and energy products to understand what components go into a well-specified system before comparing quotes.