Buying a Perth home with solar: what to check before you sign

A Perth home with an existing solar system can save you significant upfront cost — but only if the system is in good condition, the warranty is transferable, and the system is actually owned by the seller (not under a financed arrangement that transfers to you). Here's what to check before signing a contract.

Step 1: Establish ownership

Before anything else, clarify whether the solar system is owned outright by the seller.

Fully owned: The most straightforward scenario. The system was purchased outright (cash or loan, now paid off) and is a fixture of the property. The sale includes the solar system.

Solar loan still outstanding: Some sellers financed solar with a personal loan or solar finance product. The loan is secured against the seller personally, but the system is typically still a fixture of the property. Ask the seller or their solicitor to confirm the loan is discharged at settlement.

Financed under an asset-finance arrangement: In some cases (more common with commercial systems), the system is owned by a finance company and leased to the property owner. At sale, this arrangement may transfer to you or the system may be removed. Ask for written confirmation of the arrangement.

Ask your solicitor: A standard conveyancing search won't always reveal a solar financing arrangement. Ask your solicitor to add a specific question about whether any solar panels are subject to a financing, lease, or hire-purchase agreement.

Step 2: Age and expected remaining life

Panel age: Solar panels typically last 25–30 years before degradation becomes significant. A 2015-installed system is now 11 years old — still well within normal working life, but the 25-year product warranty (where applicable) has 14 years remaining, not 25.

Inverter age: String inverters typically last 10–15 years. A 10-year-old inverter in a 10-year-old system may be at or approaching end of its manufacturer warranty and practical life. Inverter replacement in 2026 costs $1,200–$2,500 depending on size.

Battery age (if present): Battery warranties are typically 10 years to 70% capacity. An 8-year-old battery has limited remaining warranty and reduced capacity. Battery replacement now costs $6,000–$14,000 depending on size.

Quick check: Ask the seller for the original installation documentation. The installation date, system size, and components should all be listed. If documentation is absent, the inverter usually has a manufacture date sticker, and the CEC accreditation database records installations.

Step 3: Warranty transfer

Most panel manufacturers allow warranty transfer to new owners, but the process is not automatic.

Panel warranty: Transfer typically requires notifying the manufacturer (or authorised partner) of the change in ownership. Some brands require this within 30–90 days of settlement. If this step is missed, warranty claims post-sale may be at risk.

Inverter warranty: Sungrow, Fronius, and SolarEdge have Perth service presence and allow warranty transfer — check the manufacturer's website for the specific process. Some brands require re-registration.

Battery warranty: BYD, Alpha ESS, and Sungrow SBR all permit warranty transfer, typically with a re-registration process through the installer or the manufacturer's online portal.

Extended warranty: If the seller registered for an extended inverter warranty (e.g., 10-year via Sungrow or Fronius portal registration), confirm this is noted in the transfer to ensure coverage continues.

Practical step: Make warranty documentation and transfer completion a condition of settlement, or ask the seller's agent to obtain it in advance. This is reasonable and routinely handled by solar installers.

Step 4: System condition

Request a monitoring report: Most modern systems (Sungrow iSolarCloud, Fronius Solar.web, SolarEdge monitoring) have cloud monitoring with historical generation data. Ask the seller to export 3–6 months of generation history. This lets you compare actual output against what the system should be producing given its size and Perth's solar resource.

What to look for:

• Consistent generation across clear days
• No days with near-zero generation unexpectedly (may indicate a fault or offline inverter)
• Any alerts or faults logged in the monitoring platform

Physical inspection: Ask your building inspector to note the solar system in their inspection. Standard building inspections cover roof condition, which includes visible panel condition. You can also ask for a specialist solar inspection ($200–$400) which includes string performance testing.

Common issues on older systems:

• Corroded DC connectors (particularly on coastal Perth properties)
• Partial shade from grown trees that weren't shading at installation
• A replaced or faulted module that was not replaced properly

Step 5: Grid connection and export rights

Export limit: A system installed before 2019 may have a higher export limit than a newly installed system would receive today. In suburbs with high solar penetration (much of Perth's inner ring), Western Power has applied export limits of 1.5–3kW on new connections. An existing connection may have a grandfathered higher export limit.

Confirm the export limit with Western Power or check the inverter settings if you have monitoring access. A higher legacy export limit is an asset worth preserving.

Feed-in tariff: The current Synergy Distributed Energy Buyback Scheme (DEBS) pays 10 cents/kWh. If the seller was on an older, higher buyback rate (e.g., the legacy Renewable Energy Buyback Scheme from pre-2020), confirm whether this rate transfers to a new owner or reverts to the current DEBS rate on a new account.

Step 6: WA Battery Scheme eligibility

If the property has a battery that was installed using the WA Battery Scheme ($130/kWh, max $1,300), the rebate has already been claimed and cannot be claimed again by a new owner on the same property. This is not a problem — the rebate is already baked into the system's value.

If the property has solar but no battery, and you want to add a battery, you may still be eligible to claim the WA Battery Scheme rebate as a new installation. Confirm the battery being added is on the Synergy Solar Secure List at the time of purchase.

Questions to ask before buying

• When was the system installed, by whom, and is original documentation available?
• Is the system fully owned, or subject to any financing, lease, or hire-purchase arrangement?
• What is the current export limit on the connection?
• What is the current feed-in tariff, and does it revert to DEBS on ownership transfer?
• Is there monitoring access, and can historical generation be shared?
• Which components are still under manufacturer warranty, and can warranty be transferred?

A Perth property with a 5–10-year-old system in good condition, with documentation and transferable warranties, is genuinely valuable. A 14-year-old system with an inverter near end of life and no documentation requires a price adjustment to reflect likely inverter replacement within 1–2 years. The condition questions above let you make that call with actual information.