A 20kWh solar battery typically costs $13,500 to $17,000 fully installed in Australia. The federal Cheaper Home Batteries discount is worth roughly $4,300 to $4,750 on a 20kWh battery, with the full rate applying to the first 14kWh and a reduced rate above that, under rules in place since 1 May 2026. Your state may add its own incentive on top.
A 20kWh battery suits large homes, whole-home backup, or multiple high-draw evening loads.
Why the rebate is lower per kWh above 14kWh
The federal Cheaper Home Batteries discount pays the full 6.8-certificate rate on the first 14kWh of a battery's usable capacity. Above that, the rate on the extra capacity steps down, so a 20kWh battery doesn't simply get 20× the per-kWh rate a 10kWh battery gets. It's still worth having, the discount on the first 14kWh alone is substantial, but don't expect the headline "$X per kWh" figure quoted for smaller batteries to scale up in a straight line. We work out your exact entitlement during your free rebate check, and see how the federal battery rebate works for the full picture.
20kWh price by brand
Indicative installed prices from brands that make a 20kWh-class battery, after the federal rebate. Ranges are brand-wide, not size-specific, since exact pricing depends on your installer, inverter setup and backup needs.
| Brand | Typical capacity range | Indicative installed (after rebate) | |
|---|---|---|---|
| Sigenergy | Roughly 5 kWh to 48 kWh, stackable in modules | $8,000 to $13,500 | Sigenergy battery → |
| Sungrow | Roughly 6.4 kWh to 25.6 kWh (SBR), up to 40 kWh per SBH stack | $6,000 to $9,000 | Sungrow battery → |
| GoodWe | Roughly 6 kWh to 30 kWh, stackable in modules | $6,000 to $9,500 | GoodWe battery → |
| AlphaESS | Roughly 9 kWh to 37 kWh single-phase, more on three-phase systems | $7,000 to $11,000 | AlphaESS battery → |
| BYD | Roughly 5 kWh to 22 kWh per tower, more with towers in parallel | $6,500 to $12,000 | BYD battery → |
| Enphase | Roughly 5 kWh and up, in modular IQ units | $7,000 to $14,500 | Enphase battery → |
| FoxESS | Roughly 5 kWh (EP5) to 90+ kWh (CQ7 stacks), in stackable modules | $7,500 to $11,000 | FoxESS battery → |
We stay brand-neutral. Your matched installer recommends whichever of these genuinely fits your roof, switchboard and usage, not the one that pays the biggest commission.
20kWh price after your state incentive
The figures above are after the federal discount only. Most states and territories add their own incentive on top, shown separately, never merged into one number:
| State | State incentive | |
|---|---|---|
| New South Wales | up to ~$1,500 (VPP) | NSW battery rebate → |
| Victoria | VPP income (loan closed) | VIC battery rebate → |
| Queensland | federal discount + VPP | QLD battery rebate → |
| South Australia | up to $2,050 (VPP) | SA battery rebate → |
| Western Australia | up to $1,300 (Synergy) or $3,800 (Horizon) | WA battery rebate → |
| Australian Capital Territory | 3% loans up to $20k | ACT battery rebate → |
| Tasmania | federal discount (loan scheme closed) | TAS battery rebate → |
| Northern Territory | federal discount (NT grant fully booked) | NT battery rebate → |
A 20kWh payback example
For a household in New South Wales with solar, a Virtual Power Plant, and an average quarterly bill around $1000, a 20kWh battery at a typical installed price of around $15,300 could save roughly $3,180 a year, paying for itself in around 4.8 years. This is an illustrative example only, based on the same model as the calculator below, not a quote. Your real figure depends on your postcode, tariff, usage pattern and battery model.