A home battery system stores solar energy generated during the day for use at night, reducing the amount of electricity you import from the grid at peak rates. Whether adding a battery to your solar system is financially rational depends on four things: your current feed-in tariff, your time-of-use electricity rates, the battery cost, and your household's after-dark consumption.
| System size | Typical installed cost (AUD) | Usable capacity |
|---|---|---|
| Small (5–7 kWh) | $7,000–$10,000 | Covers moderate evening use for smaller households |
| Medium (10–13 kWh) | $10,000–$15,000 | Most common household size; covers most overnight needs |
| Large (15–20 kWh) | $15,000–$22,000 | Larger homes or households with EVs |
The dominant battery systems in the Australian residential market are the Tesla Powerwall 3 (13.5 kWh usable), SungRow SBR series, and BYD Battery Box. Prices have fallen approximately 15–20% in the past two years as manufacturing scale has increased, but installed costs remain high relative to simple payback calculations at current electricity tariffs and feed-in rates.
The financial case for a battery depends on the gap between your import rate (what you pay to buy electricity from the grid) and your feed-in tariff (what you receive for excess solar exported to the grid). If this gap is large, keeping solar generation in a battery and using it later saves more than exporting it.
In 2026, feed-in tariffs in most Australian states are 3–8 cents per kWh. Peak electricity import rates are 35–50 cents per kWh depending on your state and plan. If you export solar at 6c and would otherwise import at 42c, using a battery to self-consume that energy instead of exporting is worth 36c per kWh of shift. A 10 kWh battery, fully cycled 300 days per year, shifts 3,000 kWh — saving approximately $1,080 per year at this differential.
At $12,000 installed cost, that is an 11-year simple payback — before accounting for battery degradation (typically 70–80% capacity retained after 10 years) and before any rebates.
The financial case for batteries is strongest in states with low feed-in tariffs, high peak import rates, and available rebates. Victoria and South Australia currently offer the best combination of these factors for battery economics.
| State | Incentive | Amount |
|---|---|---|
| Victoria | Solar Homes Battery Loan / Solar Victoria rebate | Up to $2,950 rebate; $0 interest loan up to $8,800 |
| South Australia | Home Battery Scheme (ongoing) | Up to $2,000 subsidy for eligible households |
| ACT | Sustainable Household Scheme | 0% interest loans available |
| NSW, QLD, WA | No dedicated battery rebate (as of 2026) | Federal STCs may apply for combined solar+battery installs |
Incentives change with state government budgets. Verify current availability and eligibility directly with your state energy authority before making purchasing decisions.
Several retailers and distributors in Australia offer Virtual Power Plant programs where your battery is enrolled in a network that can dispatch stored energy to the grid during high-demand periods. In return, participants typically receive a bill credit or reduced energy rates. SA Power Networks, Origin Energy, AGL, and Sonnen all operate VPP programs in various states.
VPP participation can improve the financial return of a battery by 10–20% annually, depending on the number of dispatch events and the terms of your specific program. The battery is not always fully available for your own use during dispatch events, but this trade-off is generally worth it for the additional financial return.
If your current feed-in tariff is above 10c/kWh, the economic case for a battery weakens significantly — you earn more by exporting than you save by self-consuming. If you are on a premium solar feed-in tariff of 15c+ (common for systems installed before 2012 in some states), adding a battery is likely to reduce your total financial return from solar rather than improve it. Check your feed-in tariff before proceeding.
Check whether your energy plan is as competitive as it should be before investing in battery storage.
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