What is an STC?

One certificate per megawatt hour

STCs come from the Small-scale Renewable Energy Scheme, the part of the federal Renewable Energy Target that covers rooftop solar, small wind and hydro systems, solar water heaters, air source heat pumps and, since 2025, home batteries. The scheme is run by the Clean Energy Regulator.

For a system that generates electricity, the regulator issues one STC for each megawatt hour it is expected to produce over the years left in the scheme. That expected output is called deemed generation, and it is paid up front: a certificate is created soon after the install, not year by year as the power is produced. For a battery the count is based on usable storage capacity instead.

Each certificate lives in the REC Registry, the regulator's online register, where it can be created, audited, transferred and, in the end, surrendered by the business that has to hold it.

Why the "STC rebate" is not a cheque

Nobody in government writes a cheque for STCs. The value comes from the market, and it reaches the system owner as a discount. The regulator describes it this way: most owners assign their right to create the certificates to a registered agent in exchange for a discount or a delayed cash payment.

1. The owner signs an STC assignment form, giving the right to create the certificates to a registered agent.
2. The retailer or installer takes the value off the price of the system, and sends the job and its paperwork to the agent, or to an STC trader whose agent does the rest.
3. The agent creates the certificates in the REC Registry, the regulator checks them, and the agent sells them.

Buying a system for your home? Your retailer handles all of this, and the discount should already be on your quote. See the rebates for your home. Selling systems? How to sell STCs covers the three routes and what each pays.

How many STCs a job gets

Panels: system size in kW, times the zone rating for the postcode, times the deeming years for the install year, rounded down. Australia is split into four zones by sunshine, with ratings from 1.185 in the south to 1.622 in the centre. In 2026 the deeming period is 5 years, so 6.6 kW in Melbourne is 6.6 x 1.185 x 5 = 39.10, rounded down to 39 STCs.

Batteries: usable capacity in kWh, times a factor set by the install date, rounded down. The first 14 kWh count in full, 14 to 28 kWh at 60%, 28 to 50 kWh at 15%, and nothing above 50 kWh. The factor is 6.8 in May to Dec 2026 and steps down every six months.

Solar water heaters and heat pumps: the count comes from the regulator's register of models rather than from a formula on size. The register rates each model over a system life of 10 years, and the entitlement is that rating times a multiplication factor that falls as the deeming period shortens, rounded down. STCs for heat pumps and solar hot water has the detail.

The STC calculator does the sum for any postcode, and STC zones lists every postcode range and its rating.

What one STC is worth

There is no single price, but there is a ceiling. The regulator runs the STC clearing house, where certificates sell at a fixed $40 before GST, so no buyer needs to pay more than that. The catch is time: certificates there join a queue and sell when a buyer comes along.

Most certificates change hands on the open market instead, a little below the cap. Two public reports for the last week of October 2026 put trades at about $39.65 to $39.85 before GST. Traders who buy from retailers and installers pay a little less again, for taking on the paperwork, the registry fees and the wait.

We pay $41 per STC incl GST on a home system, as at 3 November 2026, within 1 business day of approving a complete claim. That is above the $40 cap, and the regulator advises caution with prices above it, so check us as you would any trader. How STC prices work explains where each number comes from.

Who has to buy them

Electricity retailers and other liable entities. Each year the government sets the small-scale technology percentage, which fixes how many STCs they must buy and surrender in proportion to the electricity they sell. The regulator's June quarter 2026 report put that demand at 21.5 million certificates for 2026, and said the market was creating them faster than that pace needs.

Battery STCs work differently. They are not counted in the percentage, so retailers do not have to buy them. Instead the Australian Government buys certificates through the clearing house, in volumes matching the STCs created for batteries. That is why a battery certificate is worth the same as a panel certificate once it is registered.

STC vs LGC

For years the line between them sat at 100 kW: a bigger solar system had to become an accredited power station and earn LGCs over time. From 1 October 2026, solar systems over 100 kW and up to 1 MW can create STCs instead, with a fixed five-year deeming period, or take certificates under the Guarantee of Origin scheme. Mid-scale solar STCs has the detail and the dates.

What makes a system eligible

• Approved equipment. Panels, inverters and batteries must be on the Clean Energy Council's approved lists at the time of the install.
• An accredited installer. The installer must be accredited by Solar Accreditation Australia and hold an unrestricted electrical licence for the state or territory. Get Solar is a retailer: our installs are done by accredited installer partners.
• State paperwork. Every state and territory has its own electrical safety certificate, and the regulator will not accept a claim without it. Western Australia also needs a Notice of Completion.
• Written statements. The installer, the designer and the retailer each sign a compliance statement, and the owner signs the assignment form.
• Evidence from the day. Serial numbers checked under the regulator's Solar Panel Validation initiative, and photos with time, date and location.

The regulator can fail a claim that is incomplete, incorrect or ineligible, and it can ask for the documents for up to five years. What each claim needs is the same list we check before we pay.

When the scheme ends

The scheme ends with 2030, and it winds down rather than stopping. Panel systems installed in 2026 are paid for 5 years of generation. Each January that falls by one, until a system installed in 2030 gets a single year. The battery factor steps down every six months on the same path. A system installed by 31 December 2030 still gets 12 months to have its certificates created.

So the same job earns fewer certificates every year, and a job that slips from December into January loses a year's worth. The STC deeming period sets out each step and what it costs on a typical job, and battery STCs does the same for the factor.