The answer is 6.8 STCs for each kWh of usable capacity in 2026, but not every kWh counts at that rate. Since 1 May 2026 the program tiers the count, so the effective average per kWh falls as batteries get larger.
The calculation in three steps
- Take the usable capacity from the CEC listing.
- Cap it at 50 kWh. Anything above earns nothing.
- Apply 100 per cent to the first 14 kWh, 60 per cent to the next 14 kWh and 15 per cent to the final 22 kWh, then multiply by the factor for the install date.
For a 2026 install:
| Usable size | Calculation | STCs |
|---|---|---|
| 10 kWh | 10 x 6.8 | 68 |
| 14 kWh | 14 x 6.8 | 95 |
| 20 kWh | 14 x 6.8 + 6 x 0.6 x 6.8 | 119 |
| 28 kWh | 14 x 6.8 + 14 x 0.6 x 6.8 | 152 |
| 40 kWh | 28 kWh figure + 12 x 0.15 x 6.8 | 164 |
| 50 kWh | 28 kWh figure + 22 x 0.15 x 6.8 | 174 |
These are approximate; the Clean Energy Regulator rounds the final figure down.
Same maths in 2027
Swap 6.8 for 5.7 from 1 January 2027. A 14 kWh battery drops from about 95 to about 79 STCs. See the 2027 factor answer for the full table.
A rounding note
Certificates are issued in whole numbers, and the figures in this page are rounded down. A 14 kWh battery calculates to 95.2 and creates 95. For a single job the difference is small, but across a hundred jobs it is worth checking that your quoting tool rounds the same way as the regulator, so your discount matches the claim.
What this means for installers
Learn the numbers by heart for the common sizes you sell, then let the regulator’s output confirm them. To turn counts into dollars, multiply by the rate you hold in writing, found on our pricing page. The battery STC pillar covers the claim process after the sale, and the battery guide goes deeper on the program rules.