The rebate is not a grant that is worked out by a person. It is a statutory formula that produces a number of certificates, which are then valued by the market.
Part one: the certificate count
The Clean Energy Regulator takes the usable capacity of the installed battery, caps it at 50 kWh, applies the three size bands, and multiplies by the factor in force on the install date. The bands are 100 per cent to 14 kWh, 60 per cent from 14 to 28 kWh, and 15 per cent from 28 to 50 kWh. The factor is 6.8 at the time of writing, 5.7 from 1 January 2027 and 5.2 from 1 July 2027. The result is rounded down to whole certificates.
Part two: turning certificates into dollars
STCs are traded. Installers sell them to a registered trader, or to the clearing house at the fixed $40 price if they lodge through the regulator’s process. At the time of writing the market has been roughly $38 to $40. The trader pays a rate below that, and the installer passes the value on as a discount. See what an STC is worth for how pricing works.
Part three: the paperwork that makes it real
The calculation only becomes money if the claim is accepted. That requires a CEC-approved, VPP-capable battery, an accredited installer, serial numbers, installation photos and the signed STC assignment form. Photo and evidence rules tightened from 1 March 2026.
Why the order of steps matters
The tiers apply before the factor, and the rounding applies at the end. Doing it in a different order, for example multiplying by the factor and then applying a flat percentage to the total, produces a slightly different answer. Use the regulator’s output as the final figure on any claim.
What this means for you
Homeowners can use the maths to check a quote, and installers can use it to price in the factor. For examples at common sizes see how many STCs per kWh and the battery rebate calculator. The battery STC pillar gives the wider context, and how it works shows the claim steps.