Solar batteries are one of the biggest home-energy topics in Australia in 2026. They can increase solar self-consumption, reduce grid imports and provide backup when the system is designed for it. But a battery should be evaluated as an energy system, not just as a product.
How a solar battery creates value
Without a battery, excess daytime solar is generally exported to the grid. With a battery, some of that excess can be stored and used later. The value of each shifted kilowatt-hour is influenced by the grid import price you avoid, the feed-in tariff you give up, and battery losses.
Start with sizing
A useful battery size is tied to evening/overnight demand and the amount of surplus solar available to charge it. A battery that is rarely filled or rarely emptied may be oversized for the household.
Calculate an indicative battery size →
Federal battery rebate in 2026
Eligible batteries can receive support through the Cheaper Home Batteries Program. For installations from May to December 2026, the STC factor is 6.8 and support is tiered by usable capacity. The first 14 kWh receives the full factor, the next band to 28 kWh receives 60%, and the band above 28 kWh to 50 kWh receives 15%.
Estimate the federal battery STCs.
What affects installed cost?
- Battery usable capacity and chemistry.
- Hybrid inverter or battery inverter requirements.
- Single-phase or three-phase configuration.
- Backup hardware and essential-load circuits.
- Switchboard upgrades and cabling.
- Installation location and compliance work.
- Monitoring and energy-management features.
For this reason, a headline battery price is not the same as an installed system price.
How to think about payback
Simple payback is installed net cost divided by estimated annual financial value. It is useful for comparison but does not capture every factor, such as future tariff changes, degradation, maintenance, financing or opportunity cost.
Use the SunnyWatly Battery Payback Calculator as a transparent first-pass model.
Battery plus solar sizing
A large battery paired with a small solar array may rely more heavily on grid charging, while a large solar array with a very small battery may export substantial energy after the battery fills. The most efficient combination depends on household load timing and tariff structure.
Also use the Solar System Size Calculator to compare the generation side of the system.
Bottom line
In 2026, federal support has improved battery affordability, but that does not remove the need to size carefully. Compare usable capacity, power, warranty, backup capability, installed net price and the value the battery can realistically create in your home.