The solar panel rebate (STCs) explained

The solar panel "rebate" is not a cheque from the government. It is a discount that comes from small-scale technology certificates (STCs), which your system earns under a federal scheme and which your installer usually sells for you, taking the value off your price. For a typical 6.6 kW system installed in Sydney in 2026, the discount is worth about $1,670 to $1,800.

What the scheme is

The Small-scale Renewable Energy Scheme (SRES) is part of the federal Renewable Energy Target and is run by the Clean Energy Regulator (CER). It covers small systems such as rooftop solar panels, solar water heaters, heat pump water heaters and, under the Cheaper Home Batteries Program, home batteries.

Each eligible system earns certificates when it is installed. One STC represents one megawatt hour (1,000 kWh) of renewable electricity. Electricity retailers and other large electricity buyers are required by law to buy and surrender a share of these certificates each year, and that demand is what gives them a market value.

How many STCs a solar system earns

The number depends on three things:

1. System size. The rated capacity of the panels, in kilowatts (kW).
2. Where you live. The CER divides Australia into four zones by postcode. Each zone has a rating for how much energy, in megawatt hours, one kW of panels is expected to produce each year.
3. When it is installed. The deeming period is the number of years of future generation you are credited for upfront. It is 5 years for systems installed in 2026 and 4 years for 2027.

The formula is:

STCs = system size (kW) × zone rating × deeming years

Certificates come in whole numbers, so treat the figures in this guide as approximate. Your installer's calculation is the one that counts.

Zone ratings and what they mean for a 6.6 kW system

Zone ratings are from the CER's postcode table. Dollar values assume $37 to $40 per certificate. Zones follow postcode boundaries, so check yours in the CER table or ask your installer.

A worked example

Take a 6.6 kW system in Sydney (Zone 3), installed in 2026:

6.6 × 1.382 × 5 = 45.6, which gives about 45 STCs.

At $37 to $40 each, that is about $1,670 to $1,800 off the price.

Why the discount falls each year

The deeming period drops by one year every January, down to one year for systems installed in 2030, as the scheme phases out. The same system therefore earns fewer certificates each year it is delayed. For the Sydney 6.6 kW example:

• 2026: about 45 STCs, $1,670 to $1,800
• 2027: about 36 STCs, $1,330 to $1,440
• 2028: about 27 STCs, $1,000 to $1,080
• 2029: about 18 STCs, $670 to $720
• 2030: about 9 STCs, $330 to $360

The later years use today's certificate prices, which can change, so treat them as a guide only.

The drop is steady, not sudden, so it is not a reason to sign a rushed deal. What does matter is the install date. If your installation slips from December into January, your system earns fewer certificates. Ask your installer to say in writing who covers the difference if that happens.

Who creates and sells the certificates

As the owner of the system, you are entitled to create its STCs. The usual approach is to assign that right to your installer or retailer in return for a lower price at the point of sale. The installer then creates the certificates in the CER's online registry and sells them.

Installers can sell certificates on the open market, where the price moves with supply and demand, or through the CER's STC Clearing House at a fixed $40 (excluding GST). We use a range of $37 to $40 per certificate to allow for open-market prices below the clearing house price.

You can create and sell STCs yourself, but it takes registration, paperwork and time, and it is uncommon for households.

For a system to earn STCs, it has to be installed by an accredited installer (Solar Accreditation Australia now handles installer accreditation) and use eligible panels and inverters. Ask your installer to confirm both before you sign.

How to check the discount on your quote

A good quote makes the STC discount easy to see. Check these points:

• System size. The number of panels times the wattage of each panel should equal the stated size. For example, 15 panels of 440 W each make 6.6 kW.
• Number of STCs. Run the formula above with your zone and the expected install year. The quote should be close.
• Value per certificate or total discount, shown as a separate line.
• Price before and after the discount. The amount you pay should be the after-discount figure.
• The assignment form. You will usually be asked to sign a form assigning your STCs to the installer. Read it, and make sure the discount it shows matches your quote.

If the STC discount is presented as a limited-time special, or the numbers don't add up, ask why. Every eligible system gets it. Our guides on how to compare solar quotes and sales tactics to walk away from have more on this.

Batteries earn STCs too

Home batteries earn STCs through the federal Cheaper Home Batteries Program. They use a separate formula based on the battery's usable capacity, and the number of certificates per kWh steps down over time, just as it does for solar. See how the federal battery rebate works, or estimate yours with the battery rebate calculator.

State extras on top of STCs

Some states and territories add their own help for solar panels. Eligibility rules apply and programs change, so check the details before you sign:

• Victoria. Solar Victoria's Solar Homes Program offers a solar panel rebate of up to $1,400, plus an optional interest-free loan. You need to be an owner-occupier, with a combined household taxable income under $150,000 and a property valued under $3 million, and you must use an authorised retailer. The rebate is worked out after the STC discount, and you need approval before the system is installed. See Victorian rebates.
• Queensland. Supercharged Solar for Renters offers rebates to eligible landlords who install solar on rental properties. See Queensland rebates.
• ACT. The Home Energy Support program helps homeowners who hold an eligible concession card, such as a Pensioner Concession Card, DVA Gold Card or Health Care Card, with part of the cost of rooftop solar. Eligible households may also be able to get a zero-interest loan. See ACT rebates.

For other states and territories, start at our rebates hub.

The short version

• The solar "rebate" is a discount from STCs, which your installer usually claims and sells for you.
• STCs = system size (kW) × zone rating × deeming years. A 6.6 kW system in Sydney installed in 2026 earns about 45, worth about $1,670 to $1,800.
• The deeming period falls by one year each January until 2030, so the discount shrinks.
• Check your quote shows the number of STCs and the discount as separate lines.
• Victoria, Queensland and the ACT have extra programs with their own eligibility rules.