# Rebate Calculator

> Calculators for Australian home energy incentives: solar STC value by postcode zone and system size, the federal battery discount by capacity and install date, and state rebates that stack on top. Published by Timeless Energy Pty Ltd (ABN 22 647 048 520), an independent reference. Not a government website; does not administer rebates or decide eligibility. All amounts are published maximums with eligibility conditions, checked 23 September 2026. Enquiries may be referred to partner businesses (Tidy Energy and Solar Incentives) who may pay a referral fee.

Key verified figures:

- Solar formula: certificates = kW x zone rating x deeming years, rounded down; Zone 3 rating 1.382, Zone 4 rating 1.185; 5 years for 2026 installs, 4 for 2027; value = certificates x $37.
- Battery formula: usable kWh x factor x $37; factor 6.8 to 31 December 2026, 5.7 from 1 January 2027, 5.2 from 1 July 2027, 4.6 from 1 January 2028; full rate on first 14 kWh, 60% from 14 to 28 kWh.
- Worked examples: 6.6 kW Zone 4 about $1,450; 10 kW Zone 3 about $2,550; 10 kWh battery about $2,520 now and about $2,110 from 1 January 2027.

## Pages

- [Rebate Calculator](https://www.rebatecalculator.com.au)
- [check](https://www.rebatecalculator.com.au/check)
- [stc value by zone](https://www.rebatecalculator.com.au/data/stc-value-by-zone)
- [about](https://www.rebatecalculator.com.au/about)

Contact: hello@rebateindex.com.au