What are STCs in solar?
Reviewed by
Leigh McInerney
Every time your solar panel system cranks out 1 megawatt-hour of eco-friendly power, you’re rewarded with a piece known as a Small-scale technology certificate. The number of these you can collect hinges on the location of your panels, the muscle behind your system, and the timing of when you opted to hop on the renewable energy movement.
Under the Small-scale Renewable Energy Scheme (SRES), STCs are used to calculate the rebate you are entitled to when you install a solar system. The Price of a single STC fluctuates between $35 – $40 but is currently $39.90.
Example: For a 6.6kW system installed in 2025 in Zone 3 (Sydney, Brisbane) you would be awarded 54 STC.
54 x $39.90 = $2,155
Claiming Small Energy Certificates can be claimed yourself, or you can assign your solar installer to do it on your behalf, which is advisable.
You will need to:
- Ensure the solar system is eligible for STCs
- Calculate the number of STCs to claim for your system size
- Fill in the required compliance paperwork
- Join the REC registry and create your certificates
- Creating the STCs in the REC registry within 12 months of the installation date
- Get certificates validated by the Clean Energy Regulator
- Find a buyer for the STCs
What is a single STCs currently worth?
As of the writing of this article, STCs are $39.90 each. The price or value of a single STC changes because they are traded publicly, and the spot price fluctuates.
Example: A 6.6kW system in 2025 is eligible for 54 STCs (Zone 3).
54 x $39.90 = $2,155
Are The STCs Being Reduced?
Yes. The STC solar rebate is set to end at the end of 2025. So the deeming period is reduced by 1 year every year until it finishes in 2030. This means the number of STCs you will receive for your solar system installation will also reduce yearly.
One STC equals 1 megawatt hour of renewable electricity generated or displaced by your solar system between now and 2030. The closer to 2030 we get, the less power your solar system can potentially produce, so the STC is also reduced.
How to calculate my STC rebate
The STC rebate is relatively simple to calculate for any system size in any region. Firstly you need to work out which STC zone you are in, as each has a different multiple. See here to find your zone.
Formula: System size in Kilowatts x STC zone rating x current STC price
Example: 6.6kW x 1.382 x $39.90 = $2,155
Solar Rebate Calculator
Are off-grid solar systems eligible for STCs?
Under the Small-scale Renewable Energy Scheme, a stand alone off-grid solar system that is not connected to the grid would still be eligible to receive STC government rebate program.
What's the deeming period of STCs?
The deeming period of STCs is reduced every year as the Small-scale Renewable Energy Scheme (SRES) ends in 2030. 1 Small-scale Technology Certificate is equal to 1 megawatt hour of renewable energy generated or displaced, so with every year that passes the ability for that system to produce that energy (the deeming period) between now and 2030 is reduced. As such the amount of rebate is also reduced each year.
Do you pay tax on STCs?
You do not pay GST when registering or creating an STC on the REC Registry. However, other transactions relating to the purchase of panels and the installer’s service may have GST consequences for homeowners and businesses.
What is the solar rebate for 2025?
The solar rebate in 2025 varies depending on the STC zone you live, and the size of your solar system. The deeming period in 2025 is now 6 years. Below is a table showing the solar rebate in 2025 by state for a 6kW solar system.
| State | System size | Zone | Zone rating | Rebate |
|---|---|---|---|---|
| New South Wales | 6KW | 3 | 1.382 | $1,955 |
| Queensland | 6KW | 3 | 1.382 | $1,955 |
| Victoria | 6KW | 4 | 1.185 | $1,676 |
| South Australia | 6KW | 3 | 1.382 | $1,955 |
| Western Australia | 6KW | 3 | 1.382 | $1,955 |
| ACT | 6KW | 3 | 1.382 | $1,955 |
| Northern Territory | 6KW | 1 | 1.622 | $2,314 |
| Tasmania | 6KW | 4 | 1.185 | $1,676 |
When does the STC rebate end?
The STC rebate is set to end on 31st of December 2030. Between now and then any eligible system can claim a rebate on their solar system and save up to 30% off the sale and installation price.
Can you trade STCs yourself?
Small scale technology certificates are tradable certificates which you can create and trade yourself. In most cases you will assign the right to create them to a registered agent (your solar installer) in exchange for an upfront discount off the cost of your solar system. It’s far easier to do it at the point of sale as at not point are you out of pocket and need to wait for the rebate.
Are STCs worth it?
I think everyone would agree that a 30% plus discount off the price of your solar system is well worth it. Not only do you save on the upfront cost, but the payback period for the system is reduced by 1/3rd and you return on investment starts a full year earlier.
What about state rebates for Solar?
There are various state initiatives for solar including battery rebates, interest free loans for low-income households as well as other local schemes all designed to get people of all backgrounds into solar sooner.
State rebates do vary depending on the state you live. To see more on rebates at the state level, you can select from the below list to see a full account of rebates available.
