Under the Small-scale Renewable Energy Scheme, eligible systems can earn small-scale technology certificates (STCs).
Before you create STCs, you need to calculate how many STCs your system is eligible for.
Calculators
Use these calculators to work out the number of certificates your system may be eligible for.
How we calculate entitlements
The amount of STCs a system is eligible for is based on:
- the type of system
- the capacity of the system (kW)
- where the system is located
- when the system was installed
- if STCs are created over one or 5 years or a single maximum deeming period.
False or misleading information
We monitor installation dates to ensure the correct deeming period is applied. Providing false or misleading information is an offence. We may take enforcement action if you improperly create STCs.
There are different zones for small generation units, air source heat pumps and solar water heaters, based on system performance.
You can use these zones to calculate how many certificates a system is eligible for.
Solar water heaters and heat pumps
Postcode zones for solar water heaters and heat pumps ( 216 KB pdf ) Postcode zones for solar water heaters and heat pumps ( 663.52 KB docx )Solar panel systems
Postcode zone ratings and zones for solar panel systems ( 172.42 KB pdf ) Postcode zone ratings and zones for solar panel systems ( 676.12 KB docx )The deeming period is an estimate of how many years a system will generate renewable energy.
The deeming period decreases by one year each year until 2030 when the scheme ends. This reduces how many certificates you can create for your system.
| Installation year | Deeming period in years |
| 2021 | 10 |
| 2022 | 9 |
| 2023 | 8 |
| 2024 | 7 |
| 2025 | 6 |
| 2026 | 5 |
| 2027 | 4 |
| 2028 | 3 |
| 2029 | 2 |
| 2030 | 1 |
STCs entitlements for solar water heaters must be calculated using the method outlined in the Renewable Energy (Method for Solar Water Heaters) Determination 2016. We will not accept calculations based on other methodologies.
The register of solar water heaters lists how many STCs a system is eligible for based on the life of the system. This is currently set at 10 years.
Multiplication factors help calculate STCs for solar water heaters and air source heat pumps. The deeming period is multiplied by the relevant multiplication factor, rounded down to the nearest whole number.
As the deeming period decreases, the multiplication factor decreases by 0.1:
- if the deeming period is 7 years, the multiplication factor is 0.7
- if the deeming period is one year, the multiplication factor is 0.1.
| Deeming period in years | Multiplication factor |
| 9 | 0.9 |
| 8 | 0.8 |
| 7 | 0.7 |
| 6 | 0.6 |
| 5 | 0.5 |
| 4 | 0.4 |
| 3 | 0.3 |
| 2 | 0.2 |
| 1 | 0.1 |