MundoKit

Australia Battery Rebate Calculator

Enter battery capacities and two installation dates. Compare STCs at an editable installer net price or the gross clearing-house reference, subject to eligibility assumptions.

Inputs
kWh
kWh
AUD
Assumes an eligible new solar-connected system, approved products and accredited installation, with no prior battery STC claim. Grid-connected batteries and their connected inverter must be VPP-capable; joining a VPP is optional. Off-grid systems must serve a lived-in dwelling. Beyond 1 km from the grid, VPP capability is not required; within 1 km, capability is required unless written evidence from the appropriate provider shows connection costs above A$30,000, excluding extra connection extensions. Confirm battery and inverter compatibility with the installer.

Results

Estimated STC value at installer net price
A$5,320.00
Whole STCs
152
Alternative date STCs / value
127 / A$4,445.00
Selected date minus alternative value
A$875.00
Selected date breakdown: factor 6.8
Capacity in bandFactor shareUnrounded STCs
14 kWh100%95.2
14 kWh60%57.12
0 kWh15%0
  • Assumes an eligible new solar-connected system, approved products and accredited installation, with no prior battery STC claim. Grid-connected batteries and their connected inverter must be VPP-capable; joining a VPP is optional. Off-grid systems must serve a lived-in dwelling. Beyond 1 km from the grid, VPP capability is not required; within 1 km, capability is required unless written evidence from the appropriate provider shows connection costs above A$30,000, excluding extra connection extensions. Confirm battery and inverter compatibility with the installer.
  • The A$40 clearing-house reference excludes GST and fees; it is not a typical net payment or an installer discount.
  • Only the first 50 kWh usable capacity earns STCs. Total certificates are rounded down after summing the bands.
  • This estimates certificate value, not a guaranteed installer discount. Separate fees, GST treatment and state incentives are excluded. Expansion and replacement cases are outside this tool.

Results update as you type. The share link stores your inputs after the # in the address, which is not sent to our server, but anyone you send it to can read them.

This is a general estimate for information only, not tax, legal or financial advice. Real rules have more conditions than a calculator can show, so check the official source below or a qualified professional for your situation.

How it works

Use the factor for the installation and certification date. From May 2026, multiply the first 14 usable kWh by the full factor, the next 14 by 60% of it, and the next 22 by 15%. Sum then round down to whole STCs. January–April 2026 uses the untapered factor on the first 50 kWh. Value = whole STCs × selected certificate price.

The published factors are 8.4 and 6.8 in 2026, then half-year factors 5.7/5.2, 4.6/4.1, 3.6/3.1 and 2.6/2.1 for 2027–2030. Money displays to cents. No intermediate band rounding is used.

The A$40 clearing-house reference excludes GST and fees. It is a gross certificate value, not the installer discount. The editable A$35 net price is an example; use your quote.

Worked examples

28 usable kWh

May–December 2026: (14 + 14 × 0.6) × 6.8 = 152.32, rounded down to 152 STCs. At an illustrative AUD 35 each, value is AUD 5,320.

Later installation

The same capacity in January–June 2027 gives 127 STCs at factor 5.7, worth AUD 4,445 at the illustrative AUD 35 price.

Frequently asked questions

Is this a guaranteed rebate?
No. It estimates certificate value for an eligible new system. Installer fees and pricing can change the discount.
Nominal or usable capacity?
Eligibility uses nominal capacity from 5 to 100 kWh. Certificate arithmetic uses usable capacity, capped at 50 kWh.
Do I get support on capacity above 50 kWh?
No STCs are calculated on usable capacity beyond 50 kWh.
Does the date matter?
Yes. Use the installed and certified date, not the order date. This tool supports 2026–2030.
Can I use this for an expansion?
No. Existing claims and added capacity require a separate eligibility check with CER.
Must my system join a virtual power plant?
Assumes an eligible new solar-connected system, approved products and accredited installation, with no prior battery STC claim. Grid-connected batteries and their connected inverter must be VPP-capable; joining a VPP is optional. Off-grid systems must serve a lived-in dwelling. Beyond 1 km from the grid, VPP capability is not required; within 1 km, capability is required unless written evidence from the appropriate provider shows connection costs above A$30,000, excluding extra connection extensions. Confirm battery and inverter compatibility with the installer.

Sources

Last reviewed 2026-11-14; next review due by 2026-12-14. The method is written out above so you can check our math.