What a solar quote must include
Twelve items. If a quote lacks any of them, ask for a revised quote before comparing it with another.
| Item | What to look for | Why it matters |
|---|---|---|
| System size and panel count | kW DC, number of panels, panel wattage; the three must multiply | Cannot compute $/W or check the STC line without it |
| Panel brand and model | Exact model number on the Clean Energy Council approved list | "Tier 1" is a bankability term, not a quality grade; the model is what carries the warranty |
| Inverter brand, model and rating | kW AC output, single or three phase, string, hybrid or micro | Sets the export limit and most of the price gap between quotes |
| Mounting and roof type | Tin or tile, storeys, tilt frames if any | Tile and two storeys are separate line items |
| Labour and electrical | Installation, cabling, isolators, switchboard work | Switchboard upgrade must be its own line or excluded in writing |
| STC line | Certificate count, price per certificate, total deducted | Should read close to 45 certificates at about $39 for 6.6 kW in Zone 3 |
| State rebate line | Only Victoria's $1,400 applies to a panel-only system | Taken off after STCs; the installer must be Solar Victoria authorised |
| GST | Charged on the pre-STC price | A quote that shows GST on the after-STC price has the arithmetic wrong |
| Exclusions | Meter exchange, scaffold, export limiter, travel, permits | Anything not listed as included is excluded; get it in writing |
| Warranties | Product, performance, inverter, workmanship, each in years, each with who honours it | Workmanship warranty sits with the installer, not the retailer |
| Output and savings assumptions | Yield, tariff, feed-in, self-consumption share | A savings figure without its assumptions is not checkable |
| Validity, deposit, payment terms, timeline | Days the price holds, deposit amount, who lodges the connection and when | Price movements in the STC and the dollar are why quotes expire |
An annotated quote: 6.6 kW in Sydney at $6,170 net
This is a complete quote built backwards from the Solar Choice Sydney standard offer of $6,170 after STCs. The five hardware, labour and fee lines are the lowest trade prices we could find on 27 October 2026; the sixth line is what is left for cable, isolators, conduit, the vehicle, insurance, the warranty provision, overheads and margin. On a quote in front of you the shares will differ, but the shape should not: if the residual is negative at the installer's stated hardware, something named on the quote is not what will be fitted.
| Line | Amount | Share of pre-GST cost |
|---|---|---|
| 15 x 440 W N-type panels (6.6 kW DC) | $2,409 | 33% |
| 5 kW single-phase string inverter | $1,090 | 15% |
| Tin-roof mounting rails and clamps | $504 | 7% |
| Installation labour, two people, one day (award minimum) | $478 | 7% |
| Certificate processing and connection application fees | $43 | 1% |
| Cable, isolators, conduit, vehicle, insurance, warranty provision, overheads and margin (residual) | $2,680 | 37% |
| Subtotal before GST | $7,205 | 100% |
| GST at 10 per cent | $720 | |
| Price before the STC discount | $7,925 | |
| Less 45 STCs at $39 (6.6 x 1.382 x 5 years, rounded down) | minus $1,755 | |
| Price you pay (net, after STCs) | $6,170 |
In words: the panels are 33 per cent of the pre-GST cost, the inverter 15 per cent, labour at award minimum 7 per cent, and 37 per cent covers everything an installer needs to stay in business and honour a ten-year workmanship warranty. GST is charged on the $7,925 before the certificates are deducted, which is why the net price is not simply 1.1 times the ex-GST hardware.
The price lines: before STC, the STC deduction, state rebate, GST and net
Before STC. The installer's real price. For the Sydney example it is $7,925 including GST.
The STC deduction. Certificates = kW x zone rating x deeming years, rounded down. 6.6 x 1.382 x 5 = 45.61, rounded down to 45. At $39 per certificate that is $1,755. In Zone 4 (Melbourne, Hobart, Canberra) the rating is 1.185, giving 39 certificates and $1,521. The installer or a registered agent creates and sells the certificates; you assign the right to them on the paperwork. If the quote values certificates 10 per cent or more below $39, ask why: the spot price traded at $39.90 in the week of 19 to 23 October 2026. If the install slips past 1 January 2027 the deeming period drops to 4 years and the same system earns 36 certificates, $1,404; a quote should say who wears that $351.
State rebate line. Only Victoria's Solar Homes rebate reduces a panel-only quote: up to $1,400, open to new applicants in monthly allocations until 30 June 2027 (solar.vic.gov.au, checked 27 October 2026), deducted after the STC line by an authorised retailer. Every other state scheme is a loan, a battery incentive or a landlord program.
GST. 10 per cent on the pre-STC price. Net. What you pay. Compare quotes on this number divided by watts: $6,170 / 6,600 W = 0.93 per watt here. The cost per watt page has the bands by city.
System size: check the kW against your bill
Your bill shows daily average use in kWh. A kilowatt of panels makes 3.9 kWh a day in Sydney and 3.6 in Melbourne (Bureau of Meteorology exposure, Clean Energy Council yield figures). A 6.6 kW system therefore makes about 26 kWh a day in Sydney. If your daily use is 15 kWh, 6.6 kW already covers it twice over and the surplus earns the feed-in rate, 4.0c in New South Wales. A quote that sizes a 10 kW system for a 12 kWh a day household should explain why: an EV, a pool, a battery on the way, or a three-phase roof that can export it.
| City | kWh per kW a year | kWh per kW a day | 6.6 kW a day | 10 kW a day |
|---|---|---|---|---|
| Sydney | 1,424 | 3.9 | 26 | 39 |
| Melbourne | 1,314 | 3.6 | 24 | 36 |
| Brisbane | 1,533 | 4.2 | 28 | 42 |
| Perth | 1,606 | 4.4 | 29 | 44 |
| Adelaide | 1,533 | 4.2 | 28 | 42 |
Panels: brand, model, wattage, count and layout
The quote should name the exact model number, not a brand and a wattage. The model is what appears on the Clean Energy Council approved modules list, what the warranty document names and what the installer must fit. Ask for a roof layout showing each panel's position and orientation; east and west arrays on the same inverter make different amounts at different times, and a layout with a south-facing string needs a reason. "Tier 1" means the maker was bankable in a finance survey; it says nothing about the panel's efficiency, degradation or warranty. Compare those three from the datasheet instead; the cost pillar carries a tier table built from datasheets.
The inverter: why it drives the gap between quotes
The inverter sets how much the system can export, whether a battery can be added later without replacing it, and a large part of the price difference between a standard and a premium quote. The quote must state brand, model, AC rating and phase. On single phase, most networks cap the inverter at 5 or 10 kVA and exports at 5 kW or less; a 6.6 kW array on a 5 kW inverter is the normal pairing because the Clean Energy Regulator allows panel capacity up to 133 per cent of the inverter rating for STCs. Supply prices below are trade list prices; a quote marks them up.
| Type | Supply price | Unit |
|---|---|---|
| 5 kW single-phase string, budget brand | no sourced price | |
| 5 kW single-phase string, Fronius, Sungrow or GoodWe class | no sourced price | |
| 8 to 10 kW three-phase string | no sourced price | |
| 5 to 10 kW hybrid (battery ready) | $3,449 to $5,399 | AUD each, ex GST |
| Microinverters, per panel | no sourced price | AUD per unit, ex GST |
| DC optimisers, per panel | no sourced price | AUD per unit, ex GST |
Battery lines and "battery ready" claims
If the quote includes a battery, it needs its own lines: brand, model, usable kWh, the federal discount as certificates (6.8 per usable kWh on the first 14 kWh at $39: $2,652 on 10 kWh, $3,705 on 14 kWh, $4,641 on 20 kWh) and any state scheme. "Battery ready" with no battery means a hybrid inverter, which should appear as a dearer inverter line and nothing else; if the price jump is more than the hybrid premium in the inverter table, ask what else changed. Bundle pricing and $ per kWh benchmarks are on solar with a battery.
What is usually excluded, with typical prices
A base quote assumes a single-storey tin roof, single phase, a modern switchboard and no shading. Each item below is a separate line when it applies, or an exclusion in writing when it does not. The meter exchange is billed by your electricity retailer, not the installer; no retailer publishes a national fee, and the only published estimate is $0 to $300.
| Item | Typical add-on |
|---|---|
| Edge protection or scaffold (two storeys) | $1,000 to $3,500 |
| Tile roof labour | $200 to $600 |
| Three-phase inverter | $375 to $1,500 |
| Switchboard upgrade | $500 to $2,500 |
| Export limiter or dynamic export device | $200 to $500 |
| Tilt frames (per kW) | $75 to $250 |
| Optimisers or microinverters | $1,500 to $2,000 |
Output and savings: the assumptions that must be printed
A savings estimate is only as good as four printed inputs: the yield (kWh per kW a year for your city, from Bureau of Meteorology exposure or a PVsyst or SAM model), the grid rate, the feed-in tariff and the share of generation you use at home. We use 35 per cent self-consumption and state default-offer rates. A quote that promises a saving with none of those four stated has not estimated anything. Ask for the four numbers and recompute: saving = kWh x (self-consumption share x grid rate + export share x feed-in).
Warranties: four different promises, four different people
Quotes blur four warranties into one word. The table reconciles the minimums a council buyer's guide publishes with the typical ranges on installer sites. The one that fails most often is workmanship: it sits with the business that did the installation, so if the retailer subcontracted the roof work, ask whose name is on it. If the retailer closes, the manufacturer warranties survive but the workmanship warranty usually does not.
| Warranty | Published minimum | Typical in 2026 quotes | Who honours it |
|---|---|---|---|
| Panel product (materials and workmanship of the panel) | 10 years | 12 to 25 years on current N-type panels | Manufacturer |
| Panel performance (output guarantee) | 25 years | 25 to 30 years | Manufacturer |
| Inverter | 5 years | 5 to 12 years | Manufacturer; some sell paid extensions |
| Mounting and framing | 10 years | 10 to 25 years | Mounting maker |
| Workmanship (the installation itself) | 5 years | 5 to 10 years | The installer named on the SAA accreditation, or the retailer in writing |
| Defects liability | 12 months | 12 months | Retailer under the Australian Consumer Law |
Five checks on the installer, with the registers
- Accreditation of the person on the roof. Search the installer's name on the Solar Accreditation Australia register. The retailer's accreditation is not the installer's.
- Products. The panel and inverter model numbers must appear on the Clean Energy Council approved products lists, or no STCs can be created.
- Electrical licence. Check the electrician on your state's licence register (Fair Trading in NSW, Energy Safe Victoria, the QBCC and Electrical Safety Office in Queensland).
- Seller code. If the retailer claims to be an approved seller, confirm it on the New Energy Tech Consumer Code register.
- Trading history. Look up the ABN on ABN Lookup: the registration date tells you how long the entity has traded, which is the number that matters for a workmanship warranty.
Site visit or satellite quote
A satellite quote is acceptable for a simple single-storey tin roof with a modern switchboard and no shading, if the quote says the price is subject to a pre-installation inspection and names what would change it (switchboard, roof condition, access). It is not acceptable for tile roofs older than 30 years, two storeys, heritage overlays or any roof with trees nearby. Solar Victoria's quote guidance (6 March 2026) and most installer guides agree on the principle; the quote should state which kind it is.
Validity, timeline and who does what
Quotes usually hold for 30 days because the STC price and the Australian dollar move; the quote should say the period and who carries a change in the certificate price between signing and installation. After signature the retailer lodges the connection application with your distributor (Ausgrid, Endeavour, Energex, SA Power Networks and the others publish their own approval windows; see the network rules on your city and suburb pages), the installer fits the system in one day for most homes, the electrician issues the certificate of compliance, and your retailer's metering provider changes the meter. The quote should name the three parties and the step each is responsible for.
Deposit, payment terms and finance lines
A deposit should be a stated amount, held until the connection application is approved, and refundable if the network refuses the system size. Final payment is due on completion, not on delivery of hardware. If finance is offered, the quote must show the cash price and the financed total separately; "from $X a week" is a payment, not a price, and the finance page reverses it into a total cost.
Red flags, in one table
| Red flag | What it means |
|---|---|
| A 6.6 kW price under $3,222 after STCs | The sourced component floor in Zone 3 at $39 per STC; below it the hardware or labour named cannot be what arrives |
| STC line valued below $1,580 | Certificates priced more than 10 per cent under the market; the gap is recovered elsewhere |
| No panel model number, only a brand and "Tier 1" | The warranty and the approved-products listing attach to the model |
| No inverter phase or AC rating | The network export limit cannot be checked |
| No exclusions list | Scaffold, switchboard and meter work arrive as variations |
| Savings promised with no tariff or yield stated | The figure is unverifiable |
| "Rebate ends this week" pressure | The federal step-down is on 1 January; the Victorian rebate is released monthly to 30 June 2027 |
| Workmanship warranty with no named business | The person who installed it is not the one promising to fix it |
Comparing three quotes on the same terms
Put each quote into one row of this table before deciding. Any cell you cannot fill from the quote is a question for the installer.
| Field | Quote A | Quote B | Quote C |
|---|---|---|---|
| Panel model and wattage x count (kW DC) | |||
| Inverter model, AC kW, phase | |||
| Price before STC (inc GST) | |||
| STC certificates x price | |||
| State rebate line | |||
| Net price | |||
| Net $ per watt | |||
| Exclusions listed | |||
| Workmanship warranty (years, who) | |||
| Inverter warranty (years) | |||
| Panel product / performance warranty | |||
| Validity (days) and deposit |
Score your quote out of 12
One point for each of the twelve checklist items present and consistent. Twelve is a quote you can compare; nine to eleven is a quote that needs a revision; under nine is a quote to put aside. Our quote check runs the price and STC parts automatically against the index for your city.
If it goes wrong
Solar systems carry the consumer guarantees of the Australian Consumer Law regardless of the warranty wording. Complaints go first to the retailer in writing, then to your state consumer affairs or fair trading office, and for approved sellers to the New Energy Tech Consumer Code administrator. Report pressure sales and fake rebate claims to Scamwatch.
Solar quote questions
What should a solar quote include?
12 items: system size with panel count and wattage, panel model, inverter model and phase, mounting and roof type, labour and electrical scope, the STC line with certificate count and price, any state rebate line, GST on the pre-STC price, exclusions, the four warranties, output and savings assumptions, and validity, deposit and timeline.
How is the STC discount calculated on a quote?
Certificates = kW x zone rating x deeming years, rounded down: 6.6 x 1.382 x 5 = 45 in Zone 3, worth $1,755 at $39 each in October 2026. In Zone 4 it is 39 certificates, $1,521. The deduction comes after GST is applied to the full price.
What is a fair price for a 6.6kW solar quote?
$6,170 to $7,284 after STCs in Sydney in October 2026 (the Solar Choice standard and premium offers); nationally $6,774 to $8,084. Below $3,222 in Zone 3 the quote cannot cover compliant hardware and award labour at trade prices.
Why is my quote higher than the advertised price?
Usually one of the add-ons: two storeys ($1,000 to $3,500 for edge protection or scaffold), a tile roof ($200 to $600), a switchboard upgrade ($500 to $2,500) or three phase ($375 to $1,500). Each should be its own line.
What is the difference between a product warranty and a workmanship warranty?
The product warranty (10 years minimum on panels, 5 on inverters) is the manufacturer's promise about the hardware; the workmanship warranty (5 years minimum, 5 to 10 typical) is the installer's promise about the installation, and it dies with the installing business.
How long is a solar quote valid?
30 days is the usual period, because the STC price and the Australian dollar move between quote and install. The quote should state the period and who carries a change in the certificate price, especially for installs that could slip past the 1 January deeming step-down.