What is an STC?

Posted in Getting solar

What is an STC?

An STC is a small-scale technology certificate, which is kind of like a discount coupon on the cost of a solar system or any other small-scale renewable energy system (think solar hot water, small-scale wind or hydro). 

Depending on the size of the system you install and where you live, the number of STCs you’re eligible for (and therefore the total amount you’re eligible for) will vary.


How does it work?

Usually, your installer will take care of your STCs for you. They’ll calculate your STC discount and you’ll see that reflected as a point of sale discount on your quote. 

Then, on the day of your install, you’ll sign your STCs over to your installer who will trade them in for cash.  

While it is possible to claim the value of your STCs yourself, you’d need to pay a higher cost for your solar system upfront, then register your STCs with the regulator and wait in the queue. In most cases, it’s easier to let your installer take care of it. 


How are STCs calculated?

STCs work toward Australia’s Renewable Energy Target. Under this scheme, each megawatt hour of renewable energy installed is eligible for Renewable Energy Certificates (RECs). These RECs can go toward both large-scale renewable energy and small-scale renewable energy. The small-scale RECs are known as small-scale technology certificates (STCs).

Because STCs are awarded for the amount of renewable energy generation, the number of STCs you’re eligible for is dependent on the size of your system, where you live and when your solar system is installed. 

Where you live: This is called zoning and is worked out by postcode. Where you live is taken into account because your location influences how much renewable energy your system will be able to produce. After all, if you live in Victoria your solar system will generate less electricity than a solar system up in sunny Queensland.

When your system is installed: The STC scheme is scheduled to phase out by 2030, so the number of STCs you get per kW of solar installed is decreasing each year. This is called the deeming period and is essentially a countdown to 2030. So in 2019 it was 12 years, in 2020 it’s 11, in 2021 it’s 10, and so on. 

That doesn’t mean you need to worry about getting in quickly though, as many solar companies will often try and tell you. Solar system costs are also decreasing, so these two factors more or less balance each other out. At the end of the day, solar will save you plenty of money on energy whether you buy it today or in 6 months. 

So to work out the number of STCs you’ll receive for your solar installation, you’ll need to calculate:

Your solar system size (in kW) x Your postcode zone rating (which you can find here) x Deeming period (in years) = The number of STCs you’re eligible for (rounded down)


How much will STCs impact the upfront cost of my system?

The value of STCs fluctuates in the market. As of July 2020, one STC is worth around $36.

So to work out just how much you’d save, use the formula above to calculate how many STCs you’d earn and then multiply that number by $36.

For example, if you’re installing a 6.6kW solar system in Melbourne in July 2020, you’d multiply 6.6 by 1.185 by 11 for a total of 86 STCs. Multiply that by 36 for a total of around $3100 saved.

It’s important to check whether your quote has already taken the STCs into account first though. For example, our Solar and Redback Battery Package estimates include your STC discount, so you don’t need to calculate a further discount.


I’m getting solar panels and a battery. Do I get STCs?

Absolutely, but the STCs will be calculated on your solar panel installation. Batteries do not attract STCs as they do not generate renewable energy (but they are good at storing it!)


Ready to go solar?

If you’re getting solar panels installed, now is the most cost effective time to add a battery. For example, our mid-sized solar and battery package (including installation) could pay for itself in less than 7 years*. 

With solar and a battery, you can save much more on energy than if you just got solar panels. In fact, you can save up to 80% on your current bills.* 

Designed specifically for households adding solar panels and a battery at the same time, our solar and battery package brings world-leading, tier 1 solar panels together with an Australian-designed battery solution in one streamlined, cost-effective package. 

The package comes in a range of sizes depending on your energy needs, household set-up and budget. Plus there are financing options available so you can start saving with your solar and battery system now, and pay it off over time. 

To get started, get a free online system estimate here. The price you’ll see on your estimate is after the STC value has been taken off, and assumes that they are assigned to the installer on the day of the installation.

View the solar and battery package


If you already have solar, but want to add a battery, check out our solar battery package.



*This scenario is the 6.6kW system and a mid sized battery (7kWh). Assuming typical generation in Victoria and assuming battery gets cycled 90% of the time at 90% depth, solar savings are estimated at $1,734 ($0.20 average value of the solar generated, which could be 10c FiT and 30c usage rate at 50/50% as an example). Battery savings would be an additional $440 per annum, for total savings of $2,174.

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