The short version
Five numbers carry the whole story.
- 6.8. The small-scale technology certificate factor from May to December 2026 — the number of certificates a battery creates for each kilowatt-hour of usable capacity. It was 8.4 from January to April. On 1 January 2027 it becomes 5.7.
- 14, 28, 50. The thresholds that now shape the discount. The factor applies at 100 per cent up to 14 kWh of usable capacity, at 60 per cent from 14 to 28 kWh, at 15 per cent from 28 to 50 kWh, and not at all beyond 50 kWh.
- $40. The price of a certificate in the Clearing House, fixed by regulation, and the price at which the Commonwealth buys and cancels one for every certificate a battery creates. That is where the money comes from.
- $7.2 billion. The expanded program estimate announced on 13 December 2025, up from $2.3 billion, aimed at more than two million batteries and about 40 GWh of storage by 2030.
- 507,651. Subsidised batteries installed by mid-August 2026, around 14 GWh, in a scheme that opened on 1 July 2025.
Put those together and you get a subsidy that is still worth several thousand dollars on a normal household battery, is worth dramatically less than it was on a large one, and gets smaller every six months from here.
How the discount is actually calculated
There is no application form and no rebate cheque. The Cheaper Home Batteries Program is bolted onto the Small-scale Renewable Energy Scheme, the same machinery that has subsidised rooftop solar for years, and it works by letting an eligible battery create certificates that someone will buy.
Three things decide the number:
- The usable capacity of the battery, not its nominal capacity. The department’s own example: a 10 kWh nominal battery with a 90 per cent depth of discharge has 9 kWh of usable capacity, and 9 is the number that counts.
- The certificate factor on the date the battery is installed and certified — currently 6.8 per usable kWh, tapered by size.
- The price the certificates fetch. The Clearing House price is fixed in regulation at $40 excluding GST, and the Commonwealth buys through the Clearing House in volumes matching what batteries create. On the open market, certificates closed the March quarter of 2026 at $39.65 on the Clean Energy Regulator’s numbers.
Partial certificates are rounded down. Almost everyone assigns the right to create them to their installer and takes the value as an upfront discount, which is why the rebate shows up as a line on a quote rather than as money in a bank account. You can keep the certificates and sell them yourself through the REC Registry, but then you pay the full price on the day and wait.
The staircase, in dollars
Below is our arithmetic: the published factor for May to December 2026, tapered as the regulations require, valued at the fixed $40 Clearing House price. Treat these as ceilings. A retailer selling the certificates on your behalf may charge fees or take a margin, and the open market price is a shade under $40.
| Capacity band (usable) | Certificates per kWh · Value per kWh at $40 |
|---|---|
| First 14 kWh | 6.8 · $272.00 |
| Above 14 kWh to 28 kWh | 4.08 · $163.20 |
| Above 28 kWh to 50 kWh | 1.02 · $40.80 |
| Above 50 kWh | Nothing. Systems up to 100 kWh nominal remain eligible, but only the first 50 kWh of usable capacity earns certificates. |
Read that table twice before you read a quote. The twenty-ninth kilowatt-hour of a battery attracts about fifteen per cent of the support the first one does. The subsidy has not merely shrunk; it has been aimed.
Applied to whole systems, with certificate totals rounded down as the regulations require:
| Usable capacity | Certificates · Value now (May to Dec 2026) · Value under the old flat 8.4 · Change |
|---|---|
| 5 kWh | 34 · $1,360 · $1,680 · down 19% |
| 10 kWh | 68 · $2,720 · $3,360 · down 19% |
| 14 kWh | 95 · $3,800 · $4,704 · down 19% |
| 20 kWh | 119 · $4,760 · $6,720 · down 29% |
| 28 kWh | 152 · $6,080 · $9,408 · down 35% |
| 40 kWh | 164 · $6,560 · $13,440 · down 51% |
| 50 kWh | 174 · $6,960 · $16,800 · down 59% |
The old column is a counterfactual, not a rate anyone can still get: it is what the same usable capacity would have created at the flat 8.4 factor that applied until 30 April 2026. It is there because the shape of the change matters more than its size. A household buying a normal battery lost about a fifth. A household buying a very large one lost half.
Does the 30 per cent claim survive?
The program has been described since launch as “around a 30% discount”, and the department says the 1 May changes were designed to keep it at around 30 per cent across a range of sizes.
Reasoning beyond the sources: that claim is testable, and it is a claim about price as much as about policy. At $272 per usable kWh, the discount is exactly 30 per cent only where the pre-discount installed price is about $907 per usable kWh. Where a battery is cheaper than that per kilowatt-hour — and large systems generally are, because the inverter, the switchboard work and the labour spread over more storage — the percentage runs higher on the first 14 kWh. Above 28 kWh, at $40.80 per kWh, the support is under five per cent of any plausible installed price. So “around 30 per cent” is a fair description of a mainstream battery and a poor description of a big one, which is precisely what the taper was designed to do. We have not found an official worked example that reconciles the phrase with the top tier, and any quote that applies a flat 30 per cent to a 40 kWh system is arithmetic worth checking line by line.
What happens next, and when
The step-downs are already written into the regulations, which were finalised on 5 February 2026. They now happen twice a year rather than annually, and they run to the end of the scheme in 2030.
| Period | Certificate factor per usable kWh · Value of the first kWh at $40 (our arithmetic) |
|---|---|
| January to April 2026 | 8.4 · $336.00 — flat, no size taper |
| May to December 2026 | 6.8 · $272.00 — taper applies |
| January to June 2027 | 5.7 · $228.00 |
| July to December 2027 | 5.2 · $208.00 |
| 2028 | 4.6, then 4.1 · $184.00, then $164.00 |
| 2029 | 3.6, then 3.1 · $144.00, then $124.00 |
| 2030 | 2.6, then 2.1 · $104.00, then $84.00 |
On our arithmetic, the 1 January 2027 step costs a 10 kWh system about $440 (from $2,720 to $2,280), a 20 kWh system about $760 (to $4,000) and a 28 kWh system about $1,000 (to $5,080). That is real money but not a cliff, and it is roughly a sixteen per cent reduction across the sizes most people buy.
Reasoning beyond the sources: the more useful way to read the schedule is that the government has published its expectation that battery prices will fall by about the same amount, on the same timetable. If they do, waiting gains you nothing. If they do not, the step-down is a genuine price rise for the buyer. Nobody, including us, can tell you which way that goes, and a battery bought on the assumption of a specific future price is a speculation dressed as a purchase.
What the market did either side of 1 May
The response to the change was immediate, and it was mostly a scramble to beat it.
| April 2026 | A record 2.43 GWh of small-scale storage registered nationally, on SunWiz’s data — demand pulled forward ahead of the 1 May change. |
|---|---|
| May 2026 | 1.51 GWh. |
| June 2026 | 1.07 GWh, down 28.3 per cent on May and a second consecutive monthly fall — but still roughly triple the level of a year earlier. SunWiz managing director Warwick Johnston called it “a controlled reset rather than a structural decline”. |
| Average system size | 44 kWh in April, 38 kWh in May, 26.16 kWh in June. The 40 to 50 kWh band fell about 46 per cent month on month in June; the 20 to 30 kWh band grew 114 per cent and became the market’s new centre of gravity. |
| By mid-August 2026 | 507,651 subsidised batteries, around 14 GWh. The Clean Energy Regulator had counted more than 400,000 systems and 11.4 GWh by mid-May. |
Reasoning beyond the sources: the taper worked, and it worked fast. A flat per-kilowatt-hour subsidy paid people to buy storage they would rarely cycle, because every extra kilowatt-hour carried the same discount whether or not it ever emptied. Eight weeks after the thresholds landed, the average system had shrunk by about 40 per cent and the fastest-growing segment was 20 to 30 kWh. That is a policy doing exactly what it said it would do, which is rare enough to note.
There is a second-order effect worth knowing about if you have older panels. Just over half of subsidised batteries — 52 per cent — have been retrofitted to existing solar left untouched. The other 48 per cent went in alongside new, upgraded or replacement solar, and those solar systems are bigger: 11.1 kW on average against 9.1 kW for systems installed without a battery. In the first quarter of the program, 53 per cent of new rooftop solar installations came with a battery; by the first quarter of 2026 that was 71 per cent.
The part nobody put on the quote
Two conditions of eligibility have consequences that outlast the discount.
The first is that an on-grid battery must be capable of joining a virtual power plant: the inverter has to be able to connect to external parties and respond to remote signals. Participation is not required, and most people have not participated. ACCC data covering New South Wales, Victoria, South Australia and south-east Queensland found only around 24 per cent of customers with solar and batteries were in a virtual power plant.
Those who joined did better on paper. On the ACCC’s figures, median bills for virtual power plant customers were $762 to $1,093 lower than for comparable grid-only customers, against $329 to $909 lower for households with solar and a battery but no coordinating plan. The catch is the one ACCC commissioner Anna Brakey stated plainly: “When customers join a virtual power plant, they hand over control of their battery to an operator and are rewarded for its use to support the broader system. It is important customers understand this when signing up to participate in a virtual power plant.” The ACCC also found operators have significant discretion over how a participating battery is used, that customers carry most of the risk, and that batteries compatible with only some products limit the ability to switch.
The second condition is that the battery must be paired with solar. A battery installed to arbitrage grid tariffs alone is not eligible, however sensible that might look on a plan with an eight-cent overnight rate.
Growing pains, in the regulators’ own numbers
Half a million installations in thirteen months is a construction program, and it has behaved like one.
- Consumer reports to the ACCC about household batteries and new energy services rose 107 per cent year on year. Reported problems: systems that did not suit the customer’s needs, including recommendations for oversized systems, faulty installations, poor performance, long delays after deposits were taken, and difficulty getting anything resolved.
- The Clean Energy Regulator had completed 1,000 battery inspections by February and introduced additional evidence requirements for installations. It can declare products and people ineligible for the program, including on physical safety, cyber security and national security grounds.
- Accredited battery installers doubled to 8,846 since the program began.
- The ACCC has recommended an overarching duty on energy providers to deliver benefits to customers, and stronger energy-specific consumer protections, on the basis that people cannot currently compare offers, switch providers or fix problems easily enough.
Reasoning beyond the sources: an oversized-system complaint and a flat per-kilowatt-hour subsidy are the same fact seen from two ends. When the discount scaled without limit, the incentive of a salesperson and the interest of a household diverged at exactly the point where the battery stopped being able to fill itself from the roof. The taper removes most of that pressure above 14 kWh. It does not touch the deposit-and-delay problem, and it does not give a household a faster route to a remedy.
Eligibility, in one table
| Size | 5 kWh to 100 kWh nominal capacity. Certificates are created only for the first 50 kWh of usable capacity. Smaller modules may be stacked to reach the 5 kWh floor. |
|---|---|
| Solar | Required. New, existing or upgraded, under 100 kW. A grid-charged battery with no solar is not eligible. |
| Products and installers | Battery and inverter must be on the Clean Energy Council approved lists at the time of installation; the installer must be accredited by Solar Accreditation Australia and on site for set-up, installation and commissioning. |
| Virtual power plant | On-grid systems must be capable of joining one. Actually joining is optional. Off-grid systems are exempt from the requirement. |
| One per premises | Support is available once per premises, for the first installation, addition or replacement. Adding to an existing battery qualifies only if that battery never received the discount, the addition is at least 5 kWh, and the total stays within 100 kWh nominal. |
| Timing | Installed on or after 1 July 2025, with eligibility dated to the certificate of electrical compliance. Certificates can be created within 12 months of that date, but the factor is set by the installation date, not the claim date. |
| Not eligible | Portable batteries and electric vehicles. |
Stacking with state schemes
The federal discount is designed to sit alongside state and territory incentives rather than replace them, and the department says people may be eligible under multiple schemes. The detail is local and it moves.
In Western Australia, an industry cost guide updated in May 2026 lists $130 per kWh up to $1,300 for Synergy customers on the south-west grid, $380 per kWh up to $3,800 for Horizon Power customers in regional WA, and up to $5,000 for concession card holders. In New South Wales, state support has largely shifted from a standalone upfront battery rebate to an incentive tied to joining a virtual power plant under the Peak Demand Reduction Scheme; we could not verify the current NSW rates from a NSW Government page before publication, and we are not going to quote a number we could not confirm. Check your own state scheme directly, and check whether it requires a virtual power plant commitment, because that is the term most likely to bind you after the installer has gone.
Where the money comes from
This is the part of the program that gets least attention and explains why it can be adjusted so precisely.
Ordinarily, small-scale certificates are bought and surrendered by electricity retailers, who pass the cost through to everyone’s bills. Batteries are handled differently: the Commonwealth buys certificates through the Clearing House at the legislated $40 in volumes matching those created by batteries, then cancels them so they cannot re-enter the market, and the regulator excludes those volumes from the liability calculation. In 2025-26 the department bought and surrendered 98,769,427 certificates under the program. The six-month update recorded more than 21 million bought against more than 160,000 installations at that point.
The stated purpose is that battery subsidies do not land on the power bills of households that did not install one. The corollary is that the discount is a budget line, and budget lines are the sort of thing that get adjusted twice a year.
Is a battery actually worth it?
We have not modelled this and we are not going to pretend otherwise. Two published figures are worth having in front of you.
Analysis by the Australian Energy Market Commission, cited by the department early in the program, put the average household payback period at 7.3 years with program support, and found cost-efficient batteries generally beat premium brands on ten-year net present value, with the fastest returns going to households with high evening consumption. That figure dates from a period when the certificate factor was higher than it is now, so treat it as the optimistic end.
Separately, the commission found that even on a conservative outlook, increased home battery uptake could deliver a roughly 3 per cent annual reduction in bills across the energy system by flattening evening peaks — a benefit that reaches people who never buy a battery. In the June quarter alone, household battery capacity in the National Electricity Market rose 3,283 MWh, or 41 per cent.
Reasoning beyond the sources: the honest consumer test has not changed with the rebate. A battery pays when you actually use the stored energy after dark, at a tariff spread wide enough to matter, in a system small enough to fill and empty most days. The taper has quietly aligned the subsidy with that test. If your quote is for capacity you will not cycle, the government has stopped paying much toward it, and that is a signal rather than an inconvenience.
If you are getting quotes this month
- Ask for the usable capacity and the certificate count in writing. Usable is the number that earns the discount, and the total is rounded down.
- Check the discount against the tiers above: the first 14 kWh at about $272, the next 14 at about $163, anything past 28 at about $41.
- Confirm the factor is 6.8, not 8.4. Quotes prepared before May, or copied from an old template, will overstate the discount.
- Get the installation date into the contract. The factor is set by the day the compliance certificate is issued, and it drops on 1 January 2027.
- If a virtual power plant is bundled into the deal, read the operator’s terms for how often and how deeply your battery can be discharged, what you are paid, and what happens if you want to leave.
- Verify the battery is on the Clean Energy Council list and the installer is accredited by Solar Accreditation Australia, on the day you sign.
- Be cautious about large deposits. Delays after deposits are among the complaints the ACCC has recorded most often.
The bottom line
The Cheaper Home Batteries Program is the rare subsidy that has been adjusted while it is still popular. It has put more than half a million batteries on Australian homes in thirteen months, doubled the installer workforce, dragged rooftop solar upgrades along with it, and it now pays about $272 for the first kilowatt-hour of usable storage and about $41 for the twenty-ninth.
If you were waiting for the perfect moment, there is not one: the discount falls again on 1 January 2027, and it is meant to fall in step with prices. The change that matters is not the size of the rebate but its shape. The government has stopped paying you to buy a battery bigger than your roof can fill, and the market took eight weeks to agree with it.
Sources
Rates, quotes and dates above are drawn from these sources, captured 9 September 2026:
- DCCEEW — Cheaper Home Batteries Program: the around 30 per cent discount, the 5 kWh to 100 kWh range, the certificate factor table to 2030 (8.4 for January to April 2026, 6.8 for May to December 2026, 5.7 and 5.2 in 2027, and so on to 2.1 in late 2030), the 100/60/15 per cent taper at 14, 28 and 50 kWh, the 5 February 2026 amendments to the Renewable Energy (Electricity) Regulations 2001, the 13 December 2025 expansion from $2.3 billion to $7.2 billion, and the statement that the factor is set by the installation date.
- DCCEEW — Eligibility information for the Cheaper Home Batteries Program (last updated 1 May 2026): certificates for the first 50 kWh of usable capacity, the solar requirement, Clean Energy Council product accreditation and Solar Accreditation Australia installer accreditation, the virtual power plant capability requirement and the fact that participation is optional, the one-per-premises rule, the 1 July 2025 start and the certificate-of-electrical-compliance test, the 12-month creation window, the exclusion of portable batteries and electric vehicles, and the nominal versus usable capacity definition with the 10 kWh at 90 per cent example.
- DCCEEW — Small-scale technology certificates for batteries: the $40 Clearing House price set under the Renewable Energy (Electricity) Act 2000, the government purchase-and-cancel arrangement and its exclusion from the small-scale technology percentage, the 98,769,427 certificates purchased and surrendered in 2025-26, the rounding-down rule, and the taper as applied to the certificate calculation.
- energy.gov.au — Cheaper Home Batteries Program: the around 30 per cent discount from 1 July 2025 and delivery through the Small-scale Renewable Energy Scheme.
- energy.gov.au — Six months of the Cheaper Home Batteries Program: the expansion to an estimated $7.2 billion, over 160,000 installations supported and over 21,000,000 certificates purchased at that point, and the stated purpose of the 1 May 2026 adjustments.
- Minister for Climate Change and Energy — More Australians to benefit from Cheaper Home Batteries (13 December 2025): the $2.3 billion to $7.2 billion expansion, more than two million batteries and about 40 GWh by 2030, more than 155,000 installations and 3.5 GWh in under six months with about three-quarters in the suburbs and regions, the Australian Energy Market Commission finding of a possible 3 per cent annual system-wide bill reduction, the description of the tiered support, and the quotes from Chris Bowen.
- Clean Energy Regulator — Record battery and solar growth reshaping energy grid (June 2026): 7.4 GWh of installed capacity in the program’s first nine months, more than 400,000 systems and 11.4 GWh by mid-May 2026 including pending installations, the record 791 MW of small-scale solar in the March quarter, and the quote from CER Chair David Parker.
- Clean Energy Regulator — Quarterly Carbon Market Report, March quarter 2026: Small-scale Renewable Energy Scheme: the open-market certificate price of $39.65 at the end of the March quarter 2026.
- SolarQuotes — Australia’s battery boom hits 500,000. What’s changed? (17 August 2026): 507,651 subsidised batteries and about 14 GWh, the 52 per cent retrofit and 48 per cent new-or-upgraded-solar split, the rise from 53 to 71 per cent of new solar installations coming with a battery, average solar system sizes of 11.1 kW with a battery against 9.1 kW without, the 3,283 MWh (41 per cent) increase in household battery capacity in the National Electricity Market during the June quarter, the ACCC figure of around 24 per cent virtual power plant participation, the 107 per cent rise in consumer reports, 1,000 battery inspections completed by February, and accredited installers doubling to 8,846.
- Energy Storage (ess-news) — Australia home battery installs fall as market shifts to smaller systems (13 July 2026), reporting SunWiz data: 1.07 GWh registered in June 2026, down 28.3 per cent on May’s 1.51 GWh and below April’s record 2.43 GWh; average system size easing from 44 kWh in April and 38 kWh in May to 26.16 kWh in June; the 40 to 50 kWh band down about 46 per cent and the 20 to 30 kWh band up 114 per cent; the state-by-state declines; and the quotes from SunWiz managing director Warwick Johnston.
- RenewEconomy — Watchdog warns spike in home battery complaints could damage consumer trust, reporting the ACCC’s June 2026 National Electricity Market inquiry report: the 107 per cent rise in complaints, median bills $762 to $1,093 lower for virtual power plant customers and $329 to $909 lower for solar-and-battery customers without a coordinating plan, operator discretion over participating batteries, compatibility limits on switching, and the quotes from ACCC commissioner Anna Brakey. We attempted to load the ACCC’s own release and report directly and were blocked by the site, so this is a secondary source and is flagged as one.
- ACCC — Growing home battery uptake delivering lower electricity bills, but consumer protections needed: the primary release for the figures above, linked so readers can check it directly.
- energy.gov.au — Interest in batteries builds as data reveals strong returns on investment: the Australian Energy Market Commission finding of an average 7.3-year payback with program support, that cost-efficient batteries typically beat premium brands on ten-year net present value, and that households with high evening consumption see the fastest returns. Published early in the program, when the certificate factor was higher than it is now.
- SolarQuotes — Solar battery prices and system costs in Australia (last updated 12 May 2026): the Western Australian incentives of $130 per kWh up to $1,300 for Synergy customers, $380 per kWh up to $3,800 for Horizon Power customers and up to $5,000 for concession card holders. An industry guide rather than a government source, and cited as such.