For a 13.5 kWh batteryabout $3,458 now, $2,888 from 1 January 2027
Try your own size in the calculator →What changes on 1 January 2027
The rebate is paid as small-scale technology certificates (STCs). The number of certificates a battery earns is its usable capacity multiplied by an STC factor, which the Clean Energy Regulator sets for each half-year.
| Installed | STC factor per usable kWh |
|---|---|
| May to December 2026 | 6.8 |
| January to June 2027 | 5.7 |
| July to December 2027 | 5.2 |
| January to June 2028 | 4.6 |
The full schedule continues every six months to 2.1 in the second half of 2030. Source: Clean Energy Regulator, Solar batteries (page last updated 31 July 2026, read on 29 October 2026).
What it costs you, by battery size
Certificates are counted on usable capacity in three bands: the first 14 kWh at 100 % of the factor, 14 to 28 kWh at 60 %, and 28 to 50 kWh at 15 %. Dollar values below assume $38 per certificate, close to the market. The Clean Energy Regulator's clearing house pays a fixed $40 excluding GST, and the open market moves daily (CER, Renewable energy certificates). Your installer's price per certificate is what counts.
| Usable capacity | Installed by 31 Dec 2026 | Difference |
|---|---|---|
| 10 kWh | 68 STCs, about $2,584 | about $418 less |
| 13.5 kWh | 91 STCs, about $3,458 | about $570 less |
| 20 kWh | 119 STCs, about $4,522 | about $722 less |
| 30 kWh | 154 STCs, about $5,852 | about $950 less |
Try your own size and install month in the rebate calculator.
The installation date is what counts
The Clean Energy Regulator states that the number of certificates for a battery depends on its capacity and its installation date (CER, Calculate STC entitlements, last updated 18 September 2026). Signing a quote in December does not lock in the 2026 factor if the battery goes in after New Year.
How to plan before the deadline
- Ask for a written installation date. Installers are busy before a rebate cut. A quote without a date is not a plan.
- Check the quote shows the certificates. It should list the number of STCs, the price per STC and the price after the discount.
- Check eligibility first. The battery must be on the Clean Energy Council approved list, be able to join a virtual power plant, and be installed by a Solar Accreditation Australia accredited installer with a battery endorsement. Only one battery per premises earns certificates.
- Do not rush a bad deal. Missing the date costs about 16 % of the rebate on the first 14 kWh. A battery that is wrong for your home costs more than that.
Does any state add to the federal rebate?
A few do, notably WA. See battery rebates by state.
Before you get quotes: the 7-point checklist