How much does a home battery save a year?
The honest answer is: it depends on your state and your evenings. Here is what our calculator says a 10kWh battery saves when it is added to solar you already have, for the same household in every state.
The short answer
- Typical saving: about $541 a year in Tasmania up to about $1,198 in South Australia, for a 10kWh battery on existing solar.
- Payback: from about 5 years with a competitive quote in SA.
- Biggest lever: the price you pay. The same battery ranges from $7,650 to $13,500 installed.
Saving by state, 10kWh battery
One household run through our calculator in every state: existing solar, a $500 a quarter bill, about 20kWh a day, someone home part of the day, and a mid-range 10kWh battery[1].
- South Australia: about $1,198 a year.
- ACT: about $1,044 a year.
- Western Australia: about $938 a year.
- Victoria: about $874 a year.
- NSW: about $795 a year.
- Queensland: about $764 a year.
- Northern Territory: about $661 a year.
- Tasmania: about $541 a year.
Why the states differ
A battery saves the gap between what your exported solar earns and what evening power costs. In South Australia that gap is widest: about 42c a kWh to buy and about 1c to export on our calculator's rates. In Tasmania, exports still earn about 9.3c, so storing them is worth less[2].
What it means for payback
On the same household, a competitive quote pays back in about 5 years in South Australia and about 6 in Victoria[1]. A poor quote can add years. That is why the price you are quoted matters more than the brand.
What moves your own number
- Your evening use. The more you use after dark, the more a battery has to do.
- Your solar surplus. A small system may not fill the battery in winter.
- Your plan. Time-of-use and free-power plans change the value of every stored kWh.
- The price. Installed prices for the same 10kWh battery run from $7,650 to $13,500 before rebates[3].
Why two quotes for the same job can be thousands apart
Installers price the same system very differently. These are the installed price ranges our calculator works from, before rebates: the low end is what a competitive installer charges, and the high end is what a poor quote looks like.
| System | Competitive quote | Poor quote |
|---|---|---|
| 6.6kW solar system | $8,000 | $10,000 |
| 10kWh battery | $7,650 | $13,500 |
| About 15kWh battery | $12,100 | $18,000 |
- The gap usually comes from margin, the brand of panel, inverter or battery, and extras such as a switchboard upgrade or backup circuit, not from a better install.
- Get at least two or three quotes, and ask for each to be itemised: hardware brands and models, size, rebates taken off, and anything extra.
- Compare batteries on price per usable kWh, not the headline price.
Get the numbers for your own home
Two minutes of questions about your bill, roof and routine gives you the system size, what it should cost after rebates and what it saves. Your report shows on screen straight away, and no installer sees anything unless you ask.
Run my numbers, freeCommon questions
How much does a 10kWh battery save per year?
On our calculator, about $541 to $1,198 a year when added to existing solar, depending on the state. South Australia saves the most.
How long does a battery take to pay for itself?
With a competitive quote, about 5 years in South Australia and 6 in Victoria for the household above. A dearer quote takes longer.
Is a battery worth it without solar?
It can be with a free-power or time-of-use plan, but most of the saving comes from storing your own solar.
Sources
- Aussie Solar Info, How the calculator works: the battery-only scenario (existing solar, $500 a quarter bill, about 20kWh a day, home some of the day, mid-range battery), run 4 November 2026. Read 4 November 2026.
- Aussie Solar Info, How the calculator works: the electricity and feed-in rates it uses for each state, checked August 2026. Read 4 November 2026.
- Aussie Solar Info, How the calculator works: installed prices, battery sizes and the federal battery discount used by this site's calculator. Read 4 November 2026.