Ask most Perth homeowners about the solar rebate and they’ll picture a government payment landing in their bank account after installation. That’s the biggest myth about how the incentive actually works. In reality, the “rebate” is a system of tradeable certificates that shows up as a discount on your quote before you pay a cent. A reputable solar panel installations company handles the certificate paperwork and assignment on your behalf, so the reduction is already baked into the figure you’re quoted rather than something you chase afterwards.
Understanding this mechanism helps you read quotes with confidence and avoid confusion when comparing options. Let’s unpack it.
What STCs Actually Are
STC stands for Small-scale Technology Certificate. It’s a unit created under a federal scheme that rewards households and small businesses for installing eligible renewable energy systems, including rooftop solar. Each certificate represents a set amount of renewable electricity your system is expected to generate or displace over its lifetime.
This is where the confusion starts. STCs are not the same as a cash rebate, and they’re completely separate from your feed-in tariff. A feed-in tariff is the credit you receive from your electricity retailer for surplus power you export to the grid over time. STCs, by contrast, are a one-off incentive tied to the installation itself. You don’t need to sell them yourself – your installer typically buys them from you as part of the deal, which is why the value comes through as an upfront price reduction.
How the Number of STCs Is Calculated
The quantity of certificates your system generates isn’t random. Three factors drive it:
- System capacity – measured in kilowatts. A larger system produces more electricity, so it attracts more certificates.
- The deeming period – the number of years remaining until the scheme’s end date. Certificates are calculated on expected output across those remaining years, so the deeming period shrinks a little each calendar year.
- The zone rating – Australia is divided into zones based on solar radiation levels. Perth sits in a high-sunshine zone, which means systems here generate more expected output per kilowatt than in cooler, cloudier parts of the country.
Multiply these together and you arrive at the number of certificates for a given system. Because Perth’s zone rating is favourable, local installations tend to generate a healthy certificate count for their size.
Why the STC Value Fluctuates Each Year
Two moving parts affect how much the incentive is worth. The first is the deeming period. The scheme has a legislated wind-down, so each year the number of remaining years drops by one. Fewer deemed years means fewer certificates per system – a gradual reduction often described as the phase-down.
The second is the market price of a certificate itself. STCs are traded, and their price moves with supply and demand within a market framework. Because the price isn’t fixed, the exact value of the discount can shift from month to month.
For 2026, the practical takeaway is that the certificate count per system continues its steady annual reduction as the scheme approaches its planned end date. The incentive still exists and still lowers your upfront cost – it simply tapers over time rather than vanishing overnight.
How the Discount Is Applied at Point of Sale
Here’s the part that trips people up. In almost all cases, you assign the rights to your certificates to your installer in exchange for a reduced installation price. The installer then trades the certificates. This is why the incentive appears as a line item or a built-in discount on your quote rather than as a separate payment to you.
The paperwork involves creating and validating the certificates through the official registry, which requires proof of a compliant, accredited installation. Your installer manages this process end to end – registering the system, submitting the required documentation, and completing the assignment forms you sign. You don’t lodge anything with a government agency yourself.
Eligibility Conditions Perth Homeowners Must Meet
Not every installation qualifies. To be eligible for STCs, a system generally needs to satisfy several conditions:
- The installation must be carried out by an accredited installer and designed to the relevant standards.
- The panels and inverter must be approved, compliant components listed for use under the scheme.
- The system must be connected to the grid and meet the applicable electrical and safety requirements for your property.
- Documentation confirming the install, including sign-off and compliance paperwork, must be completed correctly.
If any of these conditions aren’t met, the certificates can’t be created – which is one reason accreditation and compliant components matter well beyond the incentive itself. Keeping an eye on your system after commissioning, including monitoring how your solar system performs, is a separate matter from eligibility but rounds out responsible ownership.
Common Misunderstandings When Comparing Quotes
Because the incentive is embedded, comparing quotes can be confusing if you don’t know what you’re looking at. A few points to keep in mind:
Some quotes present the price already net of the certificate discount, while others show the gross price with the discount itemised separately. Both can describe the same net outcome, so always confirm whether the figure you’re seeing is before or after the STC reduction.
A bigger system doesn’t automatically mean better value per dollar, even though it generates more certificates. The relationship between capacity, certificate count and total cost isn’t perfectly linear, so more STCs on paper doesn’t guarantee proportional savings.
Finally, the certificate value quoted at one point in time can differ slightly from another quote issued weeks later, simply because the market price moved. That’s normal, not a sign anyone is misleading you.
Reading Your Quote With Confidence
Once you understand that STCs are a certificate-based, upfront discount – not a cash rebate and not a feed-in tariff – the numbers on a solar quote make far more sense. You can see how the incentive lowers the price at the time of installation, why the amount shifts a little each year, and why an accredited installer handles the registration and assignment on your behalf.
A well-informed buyer is in a much stronger position to plan a system that genuinely suits their property and household needs. Knowing how the incentive fits into the bigger picture means fewer surprises and clearer decisions when the quotes land on your kitchen table.