Your Complete Guide to Home Batteries in WA
Understand rebates, sizing, costs, and returns for battery storage in the Synergy and Western Power network
Stack state ($1,300) and federal (~$2,713) rebates on a 10 kWh Synergy battery to significantly reduce upfront costs
Get paid $0.70/kWh during grid events through Synergy's Battery Rewards program
Store solar energy for evening use and protect against export curtailment
Eligibility Requirements
- Australian permanent resident, 18+ years old
- Synergy customer in Western Australia
- Primary residence or investment property (with landlord consent if renting)
- Battery with minimum 5kWh usable capacity
The Battery Rewards program connects home batteries into a virtual power plant, allowing Synergy to use stored energy during peak demand. In return, you earn credits and help stabilize the grid.
How You Earn
Event Credits
$0.70 per kWh exported during VPP events (up to 30 events/year, 2-6 hours each)
Offset Credits
Credits for battery charging and holding capacity
Year-Round Savings
Reduce bills by storing cheap solar and avoiding peak rates
Program Details
Step-by-Step Sizing
- Calculate daily usage: Monthly bill usage ÷ 30 days
Example: 600 kWh/month = 20 kWh/day
- Determine evening usage: Typically 40-60% of daily usage occurs after solar production
Example: 20 kWh × 50% = 10 kWh evening usage
- Apply efficiency factors: Account for Depth of Discharge (80%) and round-trip efficiency (80-90%)
Example: 10 kWh × 0.8 × 1.2 = 9.6 kWh minimum capacity
- Add buffer: Consider backup needs and future usage growth
Recommended: 13.5 kWh battery for this household
Common Battery Sizes
5-7 kWh
Small households, 1-2 people, low evening usage
10-13.5 kWh
Average households, 3-4 people, typical usage
Most PopularSince February 14, 2022, Western Power has implemented export limiting to manage grid stability. This affects how much solar energy you can send back to the grid.
Export Limits
- Systems ≤5kW: Must be remotely controllable (can be turned down/off during emergencies)
- Systems >5kW: Limited to 1.5kW or 5% of inverter capacity (whichever is greater)
With export limiting becoming more common during peak solar production (10am-2pm), batteries ensure you capture and use all your solar generation rather than losing it to curtailment.
Example: 13.5 kWh Battery System
Annual Savings Breakdown
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