How to read a solar quote in Perth: what every line item means

Getting three solar quotes is standard advice. Acting on that advice requires being able to compare those quotes intelligently — which means understanding what each line item means and what drives the price differences between quotes.

The system components and their costs

Solar panels (PV modules): Quoted in watts (W) or kilowatts (kW). A typical Perth residential quote specifies:

• Quantity of panels (e.g. "18 × 370W panels")
• Brand and model (e.g. "REC Alpha Pure 430W")
• Total system capacity in kW (e.g. "6.6kW")

Higher wattage panels of the same quality mean fewer panels for the same system output — useful if you have limited roof space. The panel brand and efficiency rating affect how much power you get per square metre of roof area.

Inverter: The device that converts solar DC electricity to AC for household use. Quoted by:

• Brand and model (e.g. "Fronius Primo 6.0kW single-phase")
• Capacity in kW (should match or slightly exceed panel capacity)
• String inverter vs microinverters vs hybrid inverter

Inverter warranty is typically listed here — note whether the quote includes extended warranty at an additional cost.

Mounting system: Rails and brackets that attach panels to your roof. The mounting hardware brand may be listed (e.g. "Clenergy racking") or described generically.

Battery (if included): Brand, model, capacity in kWh, and number of units. Also: battery chemistry (typically LFP for residential) and the number of cycles warranted.

Battery inverter/hybrid inverter (if applicable): If a battery requires a separate inverter or is in addition to an existing string inverter, this appears as a separate line.

Fees and charges

Standard installation: Labour for physically installing the system on your roof and connecting to your switchboard. Typically includes:

• Mounting hardware installation
• Panel installation
• DC cabling from roof to inverter
• AC connection from inverter to switchboard
• Inverter commissioning

Electrical work / switchboard upgrades: If your switchboard needs upgrading (older switchboards may require rewiring or replacement of ceramic fuses) before solar can be safely connected, this appears as a separate line item. This is a real cost — old switchboards can be an unexpected addition to the quote.

Metering fee / smart meter: Western Power contracts Meter Management Companies to install interval meters for solar. Some quotes include an estimated smart meter fee (typically $0–$300, often absorbed into the installation cost); others don't — ask whether the quoted price is fully inclusive of metering.

Certificate of Compliance (electrical): Your licensed electrician issues a Certificate of Compliance after completing electrical work. This is a mandatory document. Some quotes itemise this fee; most include it in installation labour.

NCN lodgement: Some quotes include a nominal fee for Western Power NCN lodgement. Often included in labour; occasionally listed separately.

Rebates and adjustments

STC deduction (most important): Small-scale Technology Certificates — the main government rebate on solar. Your installer creates and sells STCs on your behalf and applies the value as a point-of-sale discount. A 6.6kW Perth system creates approximately 90 STCs in 2026, worth approximately $3,500–$5,000 at current STC prices.

Important: STC prices fluctuate with the market. Some installers guarantee a fixed STC price (locking in your rebate); others use current market price at the time of installation. Ask which approach applies to your quote.

The quote should show:

• Gross system price (before STCs)
• STC rebate amount (as a negative line item)
• Net price you pay (gross minus STCs)

WA Battery Scheme rebate (if battery included): $130/kWh rebate, max $1,300, applied through Synergy. This is a rebate you claim through Synergy after installation, not a point-of-sale discount. Most installers will help you complete the application, but the rebate comes back to you from Synergy, not from the installer. If a quote shows the battery rebate as a price deduction, verify whether this is a Synergy rebate (you apply for it) or an actual installer discount.

What's often NOT included in quotes

Extended inverter warranty: Standard inverter warranty is 10 years. Extended to 15–20 years is available at additional cost from most inverter brands. Some quotes include extended warranty; most don't. Ask specifically.

Roof repairs or replacement: If your roof needs work before solar installation (re-pointing, broken tiles), this is typically not in the solar quote. You'd need a separate roofing quote.

Asbestos roof surcharge: Solar installation on an asbestos roof requires licensed asbestos contractors and additional procedures. If your roof has asbestos and the quote doesn't mention it, ask directly — this is a significant cost addition if required.

System monitoring subscription: Most inverter brands offer free basic monitoring apps. Advanced monitoring with extended data history, alerts, and analysis tools may require a subscription after a free trial period.

How to compare quotes intelligently

Apples-to-apples comparison: Compare quotes by specifying the same output (e.g. 6.6kW or 10kW) and asking for the price per installed kW. Price per kW normalises for system size differences.

Check panel and inverter tier: A quote with tier-1 panels and a quality inverter (Fronius, SMA, SolarEdge, Enphase, Sungrow) at $1,000 more than a quote with unknown-brand components may be better value over 25 years. Check the panel brand's production warranty (80% output at year 25), inverter warranty length, and whether the installer is CEC accredited.

Look at the net price: Always compare net prices (after STCs are deducted). Gross prices can be misleading if different installers are quoting different STC values.

Warranty terms:

• Panel product warranty (materials/workmanship): minimum 10 years, quality brands 12–15 years
• Panel performance warranty (output): 25 years at 80%+ output
• Inverter warranty: minimum 10 years
• Workmanship warranty (installation): minimum 5 years under CEC Code of Conduct

Red flags in quotes

• No STC line item or the STC deduction isn't itemised (how do you know what you're paying?)
• Unrealistically high STC value (some installers over-estimate to show a lower net price)
• No specification of panel brand or model (vague "Tier 1 panels")
• No inverter brand or model specified
• Very low price per kW from an installer you can't verify is CEC accredited
• "Price valid for 24 hours" pressure tactic (STCs change slowly; there's no reason for genuine urgency)

Three quotes from CEC-accredited installers, with full component specifications, give you the information to make a real comparison. Compare net prices, warranty terms, and component quality — not just headline numbers.