How we work this out
Usable capacity times your cost per kWh gives the sticker price before any rebate. The Cheaper Home Batteries Program discount is then subtracted: $252 for every usable kWh up to 14kWh, 60% of that rate for the next 14kWh (14–28kWh), and 15% of that rate for the next 22kWh (28–50kWh), the same tapered bands the Department of Climate Change, Energy, the Environment and Water applies from 1 May 2026. What's left is the net cost the battery actually has to earn back.
The saving side prices what the battery actually does each day: it stores solar that would otherwise have been exported at your feed-in tariff, and uses it at night instead of buying that same power back at your retail rate. The gap between those two rates, times how much energy actually cycles through the battery (capacity × your chosen daily-cycle assumption × 365 days × a 90% round-trip efficiency, the typical loss for a lithium home battery), gives the annual dollar saving. Net cost divided by that annual saving is the payback in years.
Worked example: a 10kWh battery installed at $950/kWh comes to $9,500 before any rebate. The full $252/kWh tier-one rate applies since 10kWh sits under the 14kWh threshold, a $2,520 discount, for a $6,980 net cost. On NSW's current rate (32.4c/kWh) against a 6c/kWh feed-in tariff, cycled realistically (0.85 cycles a day), that's about $737 a year in avoided bills, a payback of roughly 9.5 years.
This calculator doesn't add to My Home's running-cost tally the way an appliance calculator does. My Home totals up what a household spends running things every year; a battery is a one-off net investment with its own payback clock, not another line item on that annual bill, so it gets its own figure here instead of a spot on that tally.
Why the rebate isn't a flat percentage
The Cheaper Home Batteries Program discount is delivered as Small-scale Technology Certificates (STCs) under the Small-scale Renewable Energy Scheme, not a fixed dollar handout. From 1 May 2026 the government tapered the STC entitlement by battery size specifically because the average battery being installed had roughly doubled once the original flat-rate version of the scheme made a bigger battery cheaper per kWh than a small one. The new bands keep the discount at roughly 30% for a typical household-sized system while trimming support for very large installs. The rate itself is reviewed at least annually and is scheduled to keep stepping down every six months to 2030 as battery prices keep falling, so a battery quote from a year ago and one from today won't carry the same rebate.
What this doesn't include
This is a real payback estimate, not a guaranteed one. It leaves out a few things deliberately rather than guessing at them: battery degradation (usable capacity fades a little every year, typically covered by a 10-year manufacturer warranty rather than priced in here), any extra income from joining a virtual power plant (VPP capability is a program eligibility requirement, but actually enrolling and getting paid for grid services is a separate, retailer-specific decision), and the value of blackout backup power, which some households would pay for even at a longer payback. It also assumes your actual solar generation lines up with your actual usage pattern closely enough that the "cycle it hard or gently" setting captures the difference, real households vary more than any one slider can.
Common questions
How much is the federal home battery rebate worth?
About $252 per usable kWh for the first 14kWh of a battery system, tapering to 60% of that rate for the next 14kWh and 15% for the next 22kWh, current from 1 May 2026 (Cheaper Home Batteries Program, DCCEEW). A typical 10kWh battery gets the full $252/kWh rate throughout, a $2,520 discount.
What size battery actually gets the best rebate per kWh?
Anything up to 14kWh usable capacity gets the full tier-one rate on every kWh. Above that the rebate tapers hard, 60% of the rate from 14–28kWh and just 15% from 28–50kWh, so a bigger battery no longer gets cheaper per kWh under the current settings the way it briefly did before the 1 May 2026 changes.
Is a home battery actually worth it?
It depends on your feed-in tariff, your retail rate and how consistently you can fill and drain it. A wider gap between what you're paid to export and what you pay to import, and a battery sized to your own solar and usage rather than the biggest one a quote can fit, both shorten the payback shown here.
Does this rebate stack with state battery rebates?
In some states, yes. A handful of states run their own additional battery incentives on top of the federal STC discount this calculator prices, worth checking with your installer since state schemes vary and change independently of the federal program.
Sources
Electricity rates: AER Default Market Offer (NSW, SA, south-east QLD), Victorian Default Offer, and each remaining state's regulated tariff, current for 2026–27. Appliance figures: the energyrating.gov.au registration database (July 2026 snapshot). Methods and assumptions are described on each page.