Firstly “Small-Scale Technology Certificates” (know as STCs) are technically an incentive scheme, not a rebate. Semantics aside, STCs deliver you an upfront discount when you install a solar power system at your home. These certificates are traded (usually by your installer) in exchange for a dollar amount which is then deducted from the cost of your installation.

The number of STCs that you’re entitled to decreases on the 1st January each year. In short, the longer you wait to install solar, the smaller your discount from the STCs will be.

Only Clean Energy Council (CEC) accredited installers are able to offer STCs discounts. This is great news for you if you get 3 quotes with Solar Market, because all of the suppliers we connect you with will be CEC accredited!

In 2011, the Australian Federal Government introduced the Small-Scale Renewable Energy Scheme (or SRES) to encourage homeowners and businesses to install solar systems. STCs were introduced as the mechanism to deliver the financial incentive to people who install solar systems less than 100kW in size (For systems 100kW and bigger, Large-scale Generation Certificates, know as LGCs, apply).

An STC discount is generally applied on your quote from your installer. An STC discount is generally applied on your quote from your installer. You will usually see a total cost, the STC discount applied, and the final out-of-pocket expense after the discount. This discounted amount is generally what you have to actually pay the installer. Sometimes, you might not see the STC amount on your bill because it’s automatically applied, but you can always double check with your installer.

When your system is installed, your install will probably ask you to assign your STCs over to them so they can then trade them in exchange for the dollar amount.

Let’s take a look at how the STCs themselves are determined below…

The number of STCs your solar system is eligible for is based on the expected amount of green electricity your new solar system will generate.

4 things impact on the number of STCs and amount of discount you can receive:

Factor 1 – The size of your solar system
The bigger the system, the more green electricity your system will produce, the more STCs you are eligible for.

Factor 2 – Where you live
When it comes to calculating your STCs, where you live is known as your “Zone”. Your Zone is an important factor in determining how many STCs you’re eligible for and it’s based on your postcode.

As you can see below, Australia has been separated into 4 zones. This has been done to show you how much solar energy can be generated by systems within a specific area.

Each zone has its own rating; the higher the rating, the more STCs you’ll be eligible for and the higher the discount you’ll get back from your STCs. As you can imagine, this is because you’ll get more sunlight and therefore produce more clean energy when you’re in Darwin (Zone 2) compared to Melbourne and Hobart (Zone 4).

Factor 3 – When you install your system
When planning your system it’s important to know – the number of STCs that you’re entitled to decreases on the 1st January each year, which means the discount you get is likely to be lower too. This is called the deeming period, and it is calculated against when the Australian Federal Government plans to completely phase out the scheme which is the end of 2030. So, however many years are left to go before it’s phased out is your specific deeming period. In 2021, it’s 10 years to go until it’s phased out… in 2022, there will be 9 years to go, and so on.

Use the table below to figure out your deeming period.

Factor 4 – STC Value
While the deeming period shows you that the number of STCs you can get each year decreases, the actual dollar value of each individual STC also fluctuates. Your solar installer will give you the exact value when you chat to them or check out The Clean Energy Regulator to learn more about how they’re traded.

When you take all this into account the number of STCs you’re eligible for is dependent on how big your system is, but also where you live and when you have your solar power system installed.

Start By Calculate Your Number of STCs

The reason it’s important to know about the size of your system, your zone and the deeming period is because each of these factors are part of the STC calculation. The calculation itself is as follows:

For Example

Let’s apply this formula to a real life example. Greg is planning on installing a 6.6kW solar system on him home in Cairnes, QLD in 2022 and wants to know how many STCs will be available to him. Greg simply has to multiply these values all together and he’ll have the number of STCs available to him, in this case 82.

Greg simply has to multiply these values all together and he’ll have the number of STCs available to him, in this case 82.

Calculate Your STC Discount

Once you have your number of STCs, you can multiply that by the dollar value STCs are being traded at that moment in time to get your estimated discount amount. You can check the current market value of STCs on various trading platforms like Demand Manager.

This dollar amount will be the estimated discount you’ll get on installation day. Go you!

Remember, the number of STCs awarded decreases each year till 2030. The longer you wait the fewer STCs you’ll receive and the lower your discount at installation. Use the example below as a reference to get a better idea of the trend and how it will affect the final price of your system.