Home battery boom: what bigger rebates mean for your costs
Battery installs surged in early 2026 while rebate settings changed. Here's what it means for sizing a battery and pricing solar in Australia.
Home batteries are selling fast, but the best size depends on your household, not the headline numbers. Based on our live model, a typical 6 kWp solar system costs $8,950 including GST, and adding storage changes that figure noticeably.
What happened
According to Renew Economy, the Clean Energy Council recorded 276,011 battery installations in the first half of 2026. That is 52% more than in the previous six months.
The same report says average installed battery size peaked at 35.3 kWh in April, then fell to 26.6 kWh in June. That fall followed rebate changes in May. Renew Economy notes that a direct causal link has not been established.
Under the federal Cheaper Home Batteries Program, the discount is delivered through small-scale technology certificates (STCs). Since 1 May, according to the report, the certificate factors have become progressively lower as usable battery capacity increases. In plain terms, each extra kilowatt-hour earns less support than the ones before it. The scheme only covers systems that meet eligibility rules, including product approval and installation conditions.
The article also covers battery maker HiTHIUM, which was promoting two home systems at an Australian trade show. One is built for adding modules over time. The other is a larger single unit that can be paralleled with more units later. We haven't tested either product, and the performance claims are the manufacturer's. The useful point for buyers is the sizing question: buy for today and expand later, or buy bigger up front.
What it means for your costs
We build our figures from labour hours multiplied by local rates, plus materials, then check them against market prices and real quotes. Battery prices are normally quoted after STCs. The federal discount steps down every six months until the scheme ends in 2030. A quote that is valid today may therefore be dearer next year.
Here is how a 6 kWp solar system looks with different battery sizes, using the middle of our range:
| Option | Typical cost (incl. GST) |
|---|---|
| Solar only | $7,500 |
| With 5 kWh battery | $8,950 |
| With 10 kWh battery | $10,400 |
| With 13.5 kWh battery | $11,400 |
The overall mid-range for solar is $7,000 – $11,600. See the full options table below for lifespans and ranges.
| Material | Typical | Usual range | Lifespan |
|---|---|---|---|
| No battery | $7,500 | $5,850 – $9,750 | – |
| 5 kWh battery | $8,950 | $7,000 – $11,600 | – |
| 10 kWh battery | $10,400 | $8,100 – $13,500 | – |
| 13.5 kWh battery | $11,400 | $8,900 – $14,800 | – |
Because the rebate per kWh shrinks as capacity grows, the cost per kWh of a very large battery is likely to look less attractive than that of a mid-sized one. Don't assume that bigger is better value.
How to size a battery
The source report makes a sensible point: the right size depends on how you use power. We'd put it this way:
- Surplus rooftop solar and high evening demand: a larger battery is more likely to be used fully.
- Uncertain future load: a smaller battery now, with a system that can be expanded, may suit better. Check compatibility and the cost of extra equipment and installation before you commit.
- An EV or heat pump on the way: factor in the extra demand. A heat pump hot water system is $4,500 typical, and an EV charger is $2,500.
If you're comparing expandable and single-unit systems, ask each installer to price the expansion step as well as the first install. Ask whether new modules will work with the old ones.
State incentives
Some states add their own support. Victoria's Solar Homes program offers a solar panel rebate of up to $1,400, with a household income cap of $150,000 from 1 July 2026. Western Australia's residential battery scheme offers up to $1,300 (Synergy) or $3,800 (Horizon Power) with virtual power plant participation.
Before you sign
- Electrical work must be done by licensed tradespeople, so check the licence.
- Confirm that the battery model is eligible for the federal program and that the quote shows the STC discount separately.
- Ask how the quote changes if you delay the install.
- Run any quote through our "is my quote fair" quote checker to see how it compares with our live figures.
For a full breakdown of what solar costs in your region, see our Solar panels.