STC Rebates Australia: Calculate Your Solar & Battery Incentives
What are STCs?
Small-scale Technology Certificates (STCs) are Australian government incentives that significantly reduce the upfront cost of solar systems. When you install solar panels or batteries, your installer creates STCs based on your system size, location, and installation year. These certificates are then sold on the open market, and the value is deducted directly from your system price - meaning you pay less upfront.
The STC rebate is automatically applied by your installer, so you don't need to do anything. The discount is taken off the total system cost before you pay, making solar more affordable. For residential customers, STCs are GST-free, but GST still applies to the system price itself. The rebate amount depends on your location's zone factor, system size, and how many years remain until the scheme ends in 2031.
STC Calculator
How are Solar PV STCs calculated?
Solar PV STCs are calculated using three key factors: your system size in kilowatts, your location's zone factor (determined by postcode), and the remaining deeming period until 2031. Australia is divided into four zones based on solar irradiance - Zone 1 has the highest factor (1.622) for areas with the most sunlight, while Zone 4 has the lowest (1.185) for areas with less solar potential. The deeming period decreases by one year each year until the scheme ends in 2031, meaning installations in later years receive fewer STCs.
The formula is: System Size (kW) × Zone Factor × Deeming Period = Number of STCs. Each STC is worth approximately $38 (market value fluctuates), and the total value is deducted from your system cost. For example, a 6.6 kW system in Sydney (Zone 3, factor 1.382) installed in 2025 would generate approximately 54 STCs, worth around $2,052 in rebates. This discount is applied upfront, reducing your total system price immediately.
Battery STCs explained
Battery storage systems are also eligible for STC rebates, providing additional savings on top of solar panel rebates. To qualify, batteries must have a minimum capacity of 5 kWh, and only the first 50 kWh of capacity is eligible for STCs (larger batteries still receive rebates, but only up to the 50 kWh cap). The STC factor for batteries decreases each year - in 2025, batteries receive 9.3 STCs per kWh, declining annually until 2030.
Battery STCs work the same way as solar PV STCs - your installer creates and sells the certificates, then deducts the value from your system price. Combined with solar panel STCs, battery rebates can significantly reduce the upfront cost of a complete solar and storage system. The rebate is GST-free for residential customers, though GST still applies to the battery purchase price itself. Most homeowners find that the combined STC rebates make solar and battery systems much more affordable than paying full price.
Common questions about STCs
When is the STC discount applied?
The STC rebate is deducted from your upfront system cost by your installer. You pay the reduced price directly - you don't receive a separate payment or need to claim anything yourself. The discount is applied before you pay, making solar more affordable from day one.
Who is eligible for STCs?
All Australian homeowners and businesses installing eligible solar systems are eligible for STCs. The system must be installed by a Clean Energy Council accredited installer, and the equipment must meet Australian standards. There are no income limits or means testing - everyone qualifies based on their system size and location.
Do STCs include GST?
For residential customers (homeowners not registered for GST), STC rebates are GST-free. However, GST still applies to the full system price before the rebate is deducted. This means you pay GST on the system, but the rebate amount itself doesn't include GST. Business customers registered for GST may have different tax treatment - consult your accountant for advice.
Can I claim STCs myself?
Technically, you can create and sell STCs yourself, but it's extremely complicated and time-consuming. The process involves registering with the Clean Energy Regulator, creating certificates, finding buyers, and handling all paperwork. Almost all homeowners have their installer handle STCs - it's included in the installation service, and you simply receive the discount automatically. There's no reason to do it yourself unless you're an installer.
What happens after 2031?
The STC scheme ends in 2031, meaning systems installed after this date won't receive STC rebates. The deeming period decreases each year until then - installations in 2025 have 6 years remaining, while installations in 2030 will have just 1 year. This is why installing sooner rather than later maximizes your rebate amount.
How do STC values change over time?
STC market values fluctuate based on supply and demand, typically ranging from $30-$40 per certificate. The number of STCs you receive decreases each year as the deeming period shortens, but the market value per STC can also change. Our calculator uses the current approximate market value of $38 per STC - actual values may vary slightly when you install.
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