WA battery rebate calculator (Synergy and Horizon)
By Sithum Imarsha Last reviewed
A 13.5 kWh battery in Western Australia gets about $3,367 off if it is installed between 1 May and 31 December 2026, and pays back in about 7.4 years at our default WA rates.
Your result
Federal rebate
$3,367
13.5 weighted kWh × 6.8 = 91 STCs × $37
Batteries must be 5–100 kWh nominal.
- Price before rebate
- $12,150
- Cost after rebate
- $8,783
- Saving in year one
- $1,180
- Simple payback
- 7.4 years
- With battery wear
- 8 years
- Rates used
- 33.26c/kWh import
3c/kWh feed-in
Next change 1 January 2027. The same battery gets $2,812 (−$555).
Fix the highlighted field to update.
How we calculated this
- The rebate is the certificates (STCs) the battery earns, times the certificate price.
- The certificates come from the usable capacity that counts and the factor for the install date.
- Payback divides the cost after the rebate by the first-year saving at the electricity rates on this page.
Check the battery qualifies
13.5 kWh qualifiesdoes not qualify
Find the STC factor
May – Dec 2026: 6.8
Weight the capacity
13.5 kWh
Count the certificates
91 STCs(not eligible)
Value the certificates
91 × $37 = $3,367
Work out payback
$8,783 ÷ $1,180 = 7.4 years
This version starts with the Synergy A1 tariff. WA households can also get a state rebate on top of the federal one.
Battery schemes in Western Australia
WA Residential Battery Scheme rebate
Rebate · Open · WA Government
It is a rebate of up to $1,300 for Synergy customers and up to $3,800 for Horizon Power customers. The maximum amounts are based on 10 kWh of usable battery capacity. You must take part in a virtual power plant (VPP). A battery installed before 1 July 2025 is not eligible. The rebate is available until all 100,000 planned rebates have been given out. As of December 2025, that was expected to be until 2027. It can be used with the federal battery discount.
Source: WA Government, WA Residential Battery Scheme page, last updated 21 May 2026
WA Residential Battery Scheme loan
Loan · Open · WA Government
It is a no-interest loan of $2,001 to $10,000, repaid over 3 to 10 years. It is for households with a combined annual income of less than $210,000. It can be used with the federal battery discount.
Official source. Checked 1 October 2026.
The calculator on this page shows the federal discount only. It adds nothing from these WA schemes.
| Usable size | Saving in year one | Simple payback | Payback with battery wear |
|---|---|---|---|
| 5 kWh | $437 | 7.4 years | 8 years |
| 8 kWh | $699 | 7.4 years | 8 years |
| 10 kWh | $874 | 7.4 years | 8 years |
| 13.5 kWh | $1,180 | 7.4 years | 8 years |
| 16 kWh | $1,398 | 7.6 years | 9 years |
| 20 kWh | $1,748 | 7.8 years | 9 years |
| 30 kWh | $2,622 | 8.1 years | 9 years |
| 40 kWh | $3,496 | 8.6 years | 10 years |
Each row is for a battery installed between 1 May and 31 December 2026, at our default price of $900 per usable kWh before the rebate. Each row assumes 0.8 cycles a day, 90% round-trip efficiency and 2% battery wear a year: the defaults of the calculator on this page. Our default WA rates are 33.26c/kWh to buy power (Official source: Synergy A1 regulated tariff from 1 Jul 2026, 33.2621c/kWh (WA Energy Operators (Charges) Amendment By-laws 2026, SL 2026/140)) and 3c/kWh for the solar you export (Estimate: WattMaths single-rate pick for a two-rate scheme. The WA Government lists the Distributed Energy Buyback Scheme for Synergy customers at 10c/kWh for exports from 3pm to 9pm and 2c/kWh from 9pm to 3pm, as of 1 July 2024 (not confirmed for 2026-27)). Western Australia has the second highest first-year saving of the 7 states and territories in our calculator, each at its default rates.
New to the rebate? Read the full guide on the main battery rebate calculator.
Questions
How much is the WA battery rebate?
It is a rebate of up to $1,300 for Synergy customers and up to $3,800 for Horizon Power customers. The maximum amounts are based on 10 kWh of usable battery capacity. It can be used with the federal battery discount. The calculator on this page shows the federal discount only.
Do I have to join a VPP for the WA rebate?
Yes. You must take part in a virtual power plant (VPP). A battery installed before 1 July 2025 is not eligible. The rebate is available until all 100,000 planned rebates have been given out. As of December 2025, that was expected to be until 2027. The scheme also has a loan. It is a no-interest loan of $2,001 to $10,000, repaid over 3 to 10 years. It is for households with a combined annual income of less than $210,000.