What your Perth solar contract should include (and what to watch for)
A solar installation is a major purchase: typically $5,000–$15,000. Before you sign the contract, there are specific terms to look for and specific clauses to be cautious about. Here's what Perth homeowners should check.
A solar contract is a legally binding agreement for a significant purchase. Many homeowners sign quickly (particularly when a salesperson is present) without reviewing the specifics. Here's what a well-structured Perth solar contract should contain, and what warrants a closer look.
What the contract must specify
System specification
The contract should identify the exact equipment being installed:
- Panel model and quantity: "Longi Hi-MO 7 445W × 16 panels (7.12kW DC)" not "quality panels"
- Inverter model and capacity: "Fronius Primo GEN24 5kW" not "tier-1 inverter"
- Mounting system: Brand and product (not just "aluminium racking")
- Battery (if applicable): Brand, model, usable capacity, chemistry
If the contract says "or equivalent" next to the panel or inverter model, ask for written clarification of what "equivalent" means and the process for your approval if a substitution occurs. Substitution clauses are used when supply is constrained, but the substitution should be to an equivalent or better product, with your consent.
Pricing and inclusions
The contract should clearly state:
- Total price (inc GST)
- STC discount applied (the point-of-sale discount from Small-scale Technology Certificates)
- What is and is not included: NCN lodgement, smart meter coordination, switchboard upgrade (if needed), roof repairs (if needed), monitoring platform setup
Exclusions should be explicit. "Switchboard upgrade if required: customer's cost" is acceptable transparency. "Switchboard upgrade not included" when you have a pre-1990s switchboard that definitely needs upgrading is a cost that should be known upfront.
Warranty terms
All three warranties should be stated explicitly:
| Warranty | What to look for |
|---|---|
| Panel product | Term in years; who the warranty is with (manufacturer, not just installer) |
| Panel performance | Minimum guaranteed output at year 25 (typically ≥80%); annual degradation guarantee |
| Workmanship | Term in years (minimum 5, per CEC Code); who provides it (installer); what it covers |
The workmanship warranty clause should describe the process for making a claim: who to contact, how, and what the response time commitment is.
Completion conditions
The contract should specify what "completion" means for payment purposes:
- Installation of all hardware
- Connection to the grid (requires NCN approval, which can take days to weeks)
- System commissioning and monitoring verified operational
Some contracts define "completion" as the day panels go on the roof, before grid connection or NCN approval. Be cautious of final payment triggers that don't include verified grid connection.
Cooling-off rights in WA
Solicited purchases (you contacted the company): If you approached the installer and signed a contract at your home or their premises, you may not have a statutory cooling-off period. Consumer Protection WA's door-to-door / unsolicited contracts regulation applies to contracts where the seller contacted you, not vice versa.
However, many reputable installers offer a voluntary cooling-off period (typically 3–7 business days). Check the contract.
Unsolicited sales (they contacted you): If the installer approached you (cold call, door knock, market stall where they initiated contact), you have a 10-day cooling-off period under WA's Contracts for Door-to-Door Sales Act provisions, even for large purchases. During this period, you can cancel without penalty.
What this means in practice: If a salesperson is in your home pressuring you to sign today to "lock in a price," you can ask for 48–72 hours to review the contract. A company that refuses to give you time to review a $10,000 contract is a yellow flag.
Deposit amounts
A reasonable deposit structure for a Perth solar installation:
- 10–20% on signing to reserve materials
- Remainder on completion (as defined above, ideally including grid connection)
Be cautious of:
- Full payment upfront, before installation begins
- Deposits above 30% before any work commences
- "Finance partner" arrangements where the full loan draws down to the company before installation
If a company is asking for full payment upfront, ask why. Cash flow issues that require full prepayment can indicate financial instability, relevant to whether your warranty will be honoured in year 5.
Payment by finance / solar loan
If you're financing the installation:
Check whether the finance is personal finance or point-of-sale finance:
- Personal finance (from your bank or a lender): you arrange separately, pay the installer on completion
- Point-of-sale finance (arranged by the installer): the lender pays the installer; you repay the lender
With point-of-sale finance, understand when the loan draws down (when does the lender pay the installer?). If the full loan draws down on signing (before installation), you have fewer practical remedies if the installation doesn't proceed.
Ask: "When does the finance amount draw down to your company?"
What's not in the contract but matters
The installation timeline
The contract may specify a date or a range ("installation within 4–8 weeks"). Ask what happens if this isn't met. SAA-accredited installation companies are typically booked 4–10 weeks out in Perth's peak periods (spring/summer).
Subcontractor disclosure
As noted in our installer questions guide, ask whether the installation will be performed by directly employed staff or subcontractors. The contract itself often doesn't specify this: it's worth asking verbally and having it confirmed in writing if the answer matters to you.
After-sale support
Who do you call in 3 years if the inverter shows a fault? The contract may name the installation company, but if that company closes, your workmanship warranty has no practical value. Better installers are either large enough to be likely to persist, or are backed by manufacturer warranty support that doesn't depend on the installer's continued operation.
If something is wrong with the contract
Ask for changes in writing. If the installer agrees to something verbally (e.g. "we'll include the switchboard upgrade"), have them amend the written contract or provide a written email confirmation before you sign.
Take time to read it. A professional installer expects homeowners to read a $10,000 contract. If you're made to feel unreasonable for wanting to review the document, that's informative.
Consumer Protection WA: If you have a dispute after signing, Consumer Protection WA provides free advice at commerce.wa.gov.au or 1300 30 40 54.
A good solar contract is the same as any major purchase contract: it clearly describes what you're getting, at what price, by when, with what guarantees. The time to ask questions is before you sign.
Money-relevant figures in this article are checked against primary sources. Here’s how we check our facts.
Calculate your savings
See how much you could save with solar, batteries, and smart tariff choices
Ready to reduce your energy bills?
Get personalised recommendations and free quotes from local installers in the WattMate network.