The battery rebate was costed at $2.3bn. It is now $7.2bn.

The 30-second take

• The program’s funding estimate rose from about $2.3 billion to roughly $7.2 billion over four years.
• It has supported approximately 300,000 battery installations since launching on 1 July 2025.
• Installs went from roughly 200 a day to more than 1,500 a day, and the average battery size roughly doubled.
• The 1 May 2026 changes — faster step-downs and size tapering — are the direct response to that overshoot.
• The scheme still runs to 31 December 2030, but the trajectory is clear: support only goes down from here.

How a program triples its budget

When the Cheaper Home Batteries Program was announced, the expected cost was around $2.3 billion. The current forecast is roughly $7.2 billion over four years.

Two things drove that, and they compounded each other.

The first is that more households took it up than modelled. Battery installations went from around 200 a day before the program to more than 1,500 a day after it — a rate of adoption that few forecasts anticipated.

The second is that the households taking it up bought much bigger batteries than modelled. Average battery size roughly doubled, reaching around 40kWh by early 2026. Because the subsidy was a flat rate per kilowatt-hour, doubling the average system size doubled the average subsidy per household on top of the volume increase.

“Twice as many households buying twice as much battery is not a doubling. It is a quadrupling.”

Why this is not a failure

It is worth resisting the reflex to read a budget overshoot as a policy failure, because on the program’s own terms it worked.

The point of the scheme was to get household storage onto the grid at scale, to soak up the enormous midday solar surplus Australia now generates and release it into the evening peak. Around 300,000 batteries is a material contribution to that goal, delivered faster than a comparable amount of grid-scale storage could have been built.

The overshoot is a design problem, not an outcome problem. A flat per-kilowatt-hour subsidy with no capacity taper was always going to be exploited in the direction of larger systems, because that is what the incentive rewarded.

What the government changed in response

From 1 May 2026 the certificate calculation changed in two ways, both aimed squarely at the two causes of the overshoot.

• Faster decline. The rebate now steps down every six months instead of annually, which pulls forward the reduction in cost per installation.
• Size tapering. The certificate factor now tapers across capacity bands — full support for common household sizes, sharply reduced support above the thresholds. This directly targets the oversizing that drove average subsidy per household.

In headline terms the rate moved from about $300 per kilowatt-hour to roughly $244. The scheme still runs to 31 December 2030, so this is a reshaping rather than an ending.

What it means if you have not bought yet

The clearest read on a scheme that has overshot its budget by three times is that the direction of support is one-way. There is no plausible scenario in which the per-kilowatt-hour rate goes back up.

That is an argument for not waiting indefinitely. It is not an argument for rushing, and the distinction matters because rushing is what the last year of this market has been made of.

The rebate you lose by taking an extra month to choose properly is a few hundred dollars on a typical system. The cost of a rushed decision — a rectification you pay for, a workmanship warranty you cannot claim, a battery sized for a sales target rather than your consumption — is routinely larger than that.

• Your rebate is locked in on the installation date, not the quote or deposit date. Get the expected date and a price-protection clause in writing.
• Under the banded factors, oversizing no longer attracts proportional subsidy — so size to your evening load.
• Compare quotes with the certificate factor shown as a line item so you can see what changes if the install slips.
• Check the installer holds Solar Accreditation Australia accreditation for battery work, not solar alone.

The bigger lesson for the next scheme

Australia has now run this experiment enough times to see the pattern. A generous, simple subsidy creates a demand spike; the demand spike outruns the accredited workforce; installation quality suffers; and the scheme is then tightened in a way that penalises the households that arrive late.

The households that come out best are consistently the ones who treat the subsidy as a discount on a decision they were going to make properly anyway, rather than as the reason for the decision. That was true of the original solar rebate, and it is true of this one.

What this means for you

If you’re a homeowner

• Support only steps down from here. Do not wait for a better rebate — but do not let the step-down push you into a rushed choice either.
• The rebate is set by your install date. That single clause is worth negotiating explicitly in any contract signed near a step-down.
• A few hundred dollars of rebate is smaller than the cost of a rectification or an unclaimable workmanship warranty.
• Size the battery to your evening consumption. The banded factors have removed the subsidy logic for going bigger.

If you’re an installer

• The scheme runs to 2030 with a predictable decline. That is a planning asset — you can tell customers exactly what waiting costs them.
• Six-monthly step-downs make install-date price protection a standard contract term rather than an edge case.
• As the subsidy shrinks each half-year, price-led competition compresses. Businesses positioned on workmanship and accreditation are better placed for the back half of the scheme.

Read next

• Cheaper Home Batteries Program explained
• Federal solar and battery rebates
• How to read a solar quote
• The standard every Solar Select installer passes

Sources

Every quantitative claim on this page traces to one of the sources below — government, regulator, market operator, or independent industry reference.

• DCCEEW — Cheaper Home Batteries Program
• Clean Energy Regulator — Solar batteries and the small-scale scheme
• Clean Energy Regulator — Postcode data for small-scale installations