Sizing · 3 min read · 29 October 2026
What Size Battery Do I Need for My Home?
Battery size should follow your evening and overnight use, your spare solar and your budget. Here is how Panda sizes a home battery, step by step.
Read article →Rebates · 3 min read
Battery Rebate for a 10 vs 20 vs 30 kWh Battery
Quick answer
The federal battery discount is counted in STCs per usable kWh, with the full factor on the first 14 kWh, 60% from 14 to 28 kWh and 15% from 28 to 50 kWh. At the 2026 rate of 6.8, a 10 kWh battery earns 68 STCs and a 30 kWh battery 154. Larger batteries still earn more, but each extra kWh earns less.
How is the discount counted?
The federal Cheaper Home Batteries discount is delivered through small-scale technology certificates (STCs). The number of STCs is:
usable kWh × STC factor, tapered by size: the first 14 kWh at 100%, 14 to 28 kWh at 60%, and 28 to 50 kWh at 15%. Nothing above 50 kWh usable counts.
The factor is 6.8 for batteries installed by 31 December 2026, 5.7 from 1 January 2027 and 5.2 from 1 July 2027.
How many STCs for each size?
| Usable kWh | To 31 December 2026 (6.8) | From 1 January 2027 (5.7) | From 1 July 2027 (5.2) |
|---|---|---|---|
| 10 kWh | 68 | 57 | 52 |
| 16 kWh | 103 | 86 | 79 |
| 20 kWh | 119 | 100 | 91 |
| 24 kWh | 136 | 114 | 104 |
| 30 kWh | 154 | 129 | 118 |
Rounded down to whole STCs. Check any specific figure with the Clean Energy Regulator's calculator before relying on it.
What does the table show?
- Small batteries get the full factor on every kWh, up to 14 kWh.
- Between 14 and 28 kWh, each extra kWh earns 60% of the factor.
- Above 28 kWh, each extra kWh earns only 15%.
So a bigger battery still earns more certificates, but the discount per kWh falls as size goes up. That is one reason we size a battery from your actual use. See what size battery you need.
Does the date matter?
Yes. The factor in force on the date your battery is installed, meaning the date on the electrical compliance certificate, decides how many STCs it earns. Our battery rebates page explains the install-date rule.
A real example
We added a 16.6 kWh GoodWe battery to a home in Loftus. Its first 14 kWh sit in the full-factor band and the remaining 2.6 kWh earn 60% of the factor, which is how most mid-size home batteries are counted.
What does it mean for price?
Home batteries start from the range on our battery prices page, after rebates and including GST. Your quote shows the discount applied to your system.
Related project
A real Panda Power install that shows this topic in practice.
What it costs
Home batteries from $6,999 to about $15,999
base prices after rebates, inc GST, as at October 2026
What affects the price: battery size, brand and inverter, whether you already have solar, backup wiring, and any additional work at your home.
Base price for a standard install, after government rebates, inc GST, as at October 2026. Additional work such as switchboard upgrades, three-phase changes or complex installs is reviewed and quoted separately.
FAQs
Why does each extra kWh earn less?
The program tapers the factor by size: 100% for the first 14 kWh, 60% from 14 to 28 kWh and 15% from 28 to 50 kWh. Nothing above 50 kWh usable earns certificates.
What is an STC worth in dollars?
STC prices move daily, so we show certificate counts rather than dollar amounts. Your quote shows the discount applied to your price.
Is the table for usable or total capacity?
Usable capacity. Check the battery datasheet or your quote for the usable figure.
Related guides
More practical guides from the Panda Power team.
Related
Sources: DCCEEW, Cheaper Home Batteries Program; Clean Energy Regulator, Solar batteries; Clean Energy Regulator, Calculate STC entitlements. Last checked 5 November 2026.
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Install before 1 January 2027