Ausgridfree 11am-2pm, 6,361 kWh a year
- ToU, no battery
- $2,682
- ToU, battery charged midday
- $2,321
- Free plan, no battery
- $2,682
- Free plan, battery charged free
- $1,315
Batteries and free midday power
Yes, you can fill a home battery from the grid during the free hours and run the house on it through the evening peak, and on the numbers it is one of the strongest uses of a free-power plan. It matters most when your solar cannot fill the battery on its own: cloudy days, winter, and small or no solar systems.
Tariffs and rebate rules checked
3 hoursfree each day, 11am-2pm in NSW and South East Queensland
24 kWhdaily cap: house plus battery, everything from the grid
$1,366a year off a Sydney free-plan bill with a 10 kWh battery
The finding. In our Sydney example, a three-person home on Ausgrid that fills a 10 kWh battery in the free hours every day pays $1,315 a year on the free-power plan, against $2,321 if it charged the same battery at midday on the reference time-of-use plan. The battery does the hard part of the plan for you: it moves evening use into the free window without anyone changing a habit.
The arithmetic
A free-power plan pays off in proportion to how much use you move into the free window. Moving the dishwasher gets you a kWh or so a day. A battery can move most of your evening and overnight use.
- Charge in the window. The battery draws from the grid during the three free hours. That energy costs nothing, as long as the house and battery together stay under 24 kWh for the day.
- Discharge in the peak. From late afternoon the house runs on the battery instead of buying power at the peak rate. On Ausgrid's free-power plan, peak is 63.72c per kWh.
- Repeat daily. The free hours run every day of the year, so a battery that cycles once a day collects the saving 365 times.
Compare that with a time-of-use plan, where a battery charged at midday on Ausgrid pays the off-peak rate of 24.04c for every kWh. On a free-power plan the same charge is free, but the rest of your rates are a little higher, which is why the worked example below compares whole bills, not single rates. Our time-of-use guide explains the other periods.
Worked example: a 10 kWh battery
A three-person home on each network, using the regulator's average hourly pattern of use, with no solar. The battery takes 10 kWh a day from the free window and covers the same amount of use between 4pm and 9am. Both plans get the battery, so the comparison is fair. Same engine as our free power calculator, where you can put in your own battery size.
| Network | ToU, no battery | ToU, battery charged midday | Free plan, no battery | Free plan, battery charged free |
|---|---|---|---|---|
| Ausgridfree 11am-2pm, 6,361 kWh a year | $2,682 | $2,321 | $2,682 | $1,315 |
| Energexfree 11am-2pm, 6,169 kWh a year | $2,345 | $1,326 | $2,345 | $1,030 |
| SA Power Networksfree 12pm-3pm, 6,102 kWh a year | $3,126 | $1,962 | $3,126 | $1,244 |
Energexfree 11am-2pm, 6,169 kWh a year
- ToU, no battery
- $2,345
- ToU, battery charged midday
- $1,326
- Free plan, no battery
- $2,345
- Free plan, battery charged free
- $1,030
SA Power Networksfree 12pm-3pm, 6,102 kWh a year
- ToU, no battery
- $3,126
- ToU, battery charged midday
- $1,962
- Free plan, no battery
- $3,126
- Free plan, battery charged free
- $1,244
Annual cost including supply charges and GST, at the regulated maximum prices for 2026-27. The model does not include charging and discharging losses or battery wear, so real savings will be somewhat lower. It does not include the cost of the battery.
When grid charging beats solar charging
If you have solar, your battery normally fills from your own panels for nothing more than the feed-in tariff you give up, and free-power plans tend to pay 0-5c per kWh for exports anyway. So on a sunny summer day, the free grid hours add little. They earn their place:
- On cloudy days and in winter, when the panels cannot fill the battery before the peak.
- With a small solar system that covers the house at midday but has little left for the battery.
- With no solar at all. A grid-charged battery works the free window every day of the year.
- With a battery bigger than your solar surplus, where the free hours top up what the panels could not.
If you export a lot, check what the free-power plan pays you for exports compared with your current plan: see solar feed-in tariffs.
The catches
- Controlled load is excluded. Anything on a separately metered controlled load circuit, often hot water or a pool pump, is outside the free window and keeps its own rate. A battery does not change that.
- The cap covers everything. The 24 kWh limit is per day for all your grid use in the window. Above it you pay the plan's above-cap rate.
- Three hours is not long. Your battery's maximum charge rate decides how much it can take in the window. Check the specification, and whether your inverter can be scheduled to charge from the grid.
- Losses. Some energy is lost going into and out of a battery, so you get back a little less than you put in. We have not found an official figure to quote; ask your installer for your system's round-trip efficiency.
- Virtual power plants. If your battery is enrolled in a retailer's VPP, the retailer may control when it charges and discharges, and the VPP may require a specific plan. Check before switching to a free-power plan.
The federal battery discount
The Australian Government's Cheaper Home Batteries Program, running since 1 July 2025, gives households a discount of around 30% on the upfront cost of a small-scale battery of 5 kWh to 100 kWh, according to the federal energy department. The discount is for batteries connected to new or existing solar PV systems, and it is delivered through small-scale technology certificates that your installer usually claims and takes off the price.
Two changes started on 1 May 2026. The certificate factor per kWh of usable capacity fell from 8.4 to 6.8 for installations from May to December 2026, and it steps down every six months to 2.1 in late 2030. Support also now tapers with size: full rate for the first 14 kWh, 60% for each kWh from 14 to 28 kWh, and 15% from 28 to 50 kWh. The date your battery is installed sets your discount.
In South Australia, where the free hours run 12pm-3pm, readers wanting installer quotes can try SA Home Battery, a site run by the same publisher as this one.
Before you switch
Check you are eligible with our eligibility checker, see which retailers offer the plan on the retailer register, and run your own numbers in the calculator with your battery's usable capacity as the amount you move each day. For every plan at your address, including battery and VPP plans we do not cover, use Energy Made Easy or Victorian Energy Compare.
Common questions
Can I charge my home battery with the free midday electricity?
Yes. The free hours apply to all your grid use in the window except controlled load, up to the daily cap of 24 kWh, and a battery charging from the grid counts as use. Check that your battery can be set to charge from the grid at set times, and that its charge rate can fill it within three hours.
Is it better to charge a battery from solar or from free grid power?
On a sunny day with a decent solar system, your panels will usually fill the battery anyway, and free-power plans pay little for exports. Grid charging earns its keep on cloudy days, in winter, and in homes with small or no solar, where the battery would otherwise sit half empty at the start of the peak.
Does the federal battery rebate need solar panels?
The Cheaper Home Batteries Program discount is for batteries connected to new or existing solar PV systems, according to the federal energy department. It works through certificates under the Small-scale Renewable Energy Scheme, and the discount per kWh steps down every six months to 2030. Ask your installer how many certificates your system earns.
Will charging a battery at midday push me over the 24 kWh cap?
Only with a very large battery or very high daytime use. The cap counts everything you draw from the grid in the window: the battery plus whatever the house uses at the same time. Anything above 24 kWh is charged at the plan's above-cap rate, which is a normal paid rate, not free.
Sources
- AER, Default Market Offer 2026-27 final determination (Solar Sharer Offer caps, 24 kWh daily cap), checked 17 October 2026
- Victoria Government Gazette S 498, Midday Power Saver Pricing Order 2026, checked 17 October 2026
- energy.gov.au, Solar Sharer Offer (controlled load and eligibility), checked 17 October 2026
- DCCEEW, Cheaper Home Batteries Program (discount, 1 May 2026 changes, STC factor to 2030), checked 17 October 2026
- AER, Residential load profiles and household benchmarks used in the worked example, checked 17 October 2026