A Melbourne customer's AGL bill went from $3.37 a day to $1.17 a day a year after solar and a battery. Grid use fell 88% and the bill fell 65%. The gap between the two is the daily supply charge.
One of our Melbourne customers sent us their latest AGL bill a year after their solar panels and battery went in. The usage and cost snapshot on page one says it plainly: $1.17 a day this bill period, against $3.37 a day for the same bill period last year. AGL’s own summary line reads “65% lower cost compared to last year”.
That is a good result, and it is worth reading closely, because the two numbers under the dollar figures tell a more useful story. The household’s electricity from the grid fell from 9.43 kWh a day to 1.10 kWh a day, a drop of 88%. The bill fell 65%. The gap between those two percentages is the daily supply charge, and once a battery is doing its job, that fixed charge becomes most of what you pay.
This article walks through the bill, explains why it did not reach zero, shows what the supply charge costs across Victoria in 2026-27, and sets out what that means when you choose a battery and an electricity plan. One household is not a prediction for yours, and we say where the differences come from.
Here is the snapshot as AGL printed it. No personal details are shown.
Laid out as a table, with the change worked out from AGL’s figures:
| Same bill period last year | This bill period | Change | |
|---|---|---|---|
| Average cost per day | $3.37 | $1.17 | $2.20 a day less, 65% lower |
| Average grid electricity per day | 9.43 kWh | 1.10 kWh | 8.33 kWh a day less, 88% lower |
Comparing the same bill period a year apart matters. It takes most of the season out of the comparison: the same months of the year, with similar daylight hours. It does not remove everything. The weather is never identical, the household’s own use can change, and tariffs move every 1 July.
An electricity bill has two main parts. The usage charge is what you pay for each kilowatt hour you take from the grid. The daily supply charge is a fixed amount you pay for every day you are connected, whether you use 30 kWh that day or none at all.
Solar and a battery attack the first part. During the day the panels run the home, and the battery stores the surplus so the evening and overnight hours can run on stored solar instead of grid power. That is how this home went from 9.43 kWh a day from the grid to 1.10 kWh. The battery has no effect on the second part. You pay the supply charge as long as the home stays connected to the grid.
The arithmetic shows how little of the $1.17 is usage now. At the regulated 2026-27 Victorian Default Offer usage rates, 1.10 kWh costs between 29 and 35 cents a day, depending on the network zone. The rest of the $1.17 is the daily supply charge, less whatever solar credits the bill applied. Before the battery, usage was the bigger number. After the battery, the fixed charge is.
The daily supply charge is a fixed charge, in dollars per day, that covers the cost of keeping your home connected to the poles and wires. It is set by your retailer, and it varies with your distribution zone, the company that owns the network in your area. In Victoria the Essential Services Commission sets the Victorian Default Offer, a regulated benchmark price. For 1 July 2026 to 30 June 2027, the default offer’s domestic flat tariff has a daily supply charge between $1.19 and $1.38 including GST, which is between about $435 and $504 a year before you use a single kilowatt hour. Market offers from retailers can be higher or lower than the default offer.
| Distribution zone | Daily supply charge | Per year | Usage rate (flat tariff) |
|---|---|---|---|
| United Energy | $1.1912 | about $435 | 27.35c per kWh |
| CitiPower | $1.2114 | about $442 | 25.96c per kWh |
| Jemena | $1.2713 | about $464 | 27.47c per kWh |
| AusNet Services | $1.2824 | about $468 | 31.98c per kWh |
| Powercor | $1.3805 | about $504 | 28.22c per kWh |
Source: Essential Services Commission, Victorian Default Offer, domestic flat tariffs from 1 July 2026 to 30 June 2027, including GST. Yearly figures are our arithmetic over 365 days.
Your distributor is named on your bill, usually in the section about faults and emergencies. You cannot choose your zone; it is set by where you live. What you can choose is the retailer and the plan.
This is the practical lesson from the bill, and the one most battery owners miss. The plan that was cheapest for you before the battery may not be the cheapest after it.
Before the battery, this household took 9.43 kWh a day from the grid. A plan with a usage rate 5 cents per kWh lower would have saved about $172 a year. After the battery, at 1.10 kWh a day, the same 5 cent difference is worth about $20 a year. A supply charge 20 cents a day lower is worth $73 a year whatever you use. These are illustrative figures from simple arithmetic, not an estimate for any particular plan, but they show where the weight has moved.
When you compare plans after installing a battery, check these in order:
The Victorian Government’s Victorian Energy Compare site lets you enter your own usage and see every plan available at your address, including each plan’s supply charge.
We share this bill because it is real, and real results vary. Four things decide how close a home gets to this one:
This household still took 1.10 kWh a day from the grid. That is common even with a well-sized system: a run of cloudy days, a heavy appliance in the early morning before the panels produce much, or a minimum charge the battery is set to keep in reserve all add a little. The useful test is whether the system matches how your home uses power.
This is why we ask for a recent electricity bill before we recommend a battery size. The bill tells us how much you use each day, how much of it lands in the evening, what tariff you are on and what you pay to be connected. Those numbers decide the right size more than any brochure figure.
A bill check answers questions like these:
If you want to see how we size a battery from usage, our guide to what size home battery you need works through it step by step. If you are still deciding whether a battery makes sense at all, start with is a home battery worth it in Victoria.
We have two offers running this month. Neither one is the system in the bill above. Both start with the same bill check.
For both packages, a switchboard upgrade, meter or network requirements, and where the battery can safely go can change the price. You get a written quote with the final figure before anything is booked. For how the federal battery discount and Victorian rebates work, see our Victorian battery rebate guide.
Because of the daily supply charge. Solar and a battery cut the electricity you buy from the grid, but you still pay a fixed daily charge for being connected. Under the 2026-27 Victorian Default Offer that charge is between $1.19 and $1.38 a day including GST, depending on your distribution zone. Most battery homes also take a little from the grid on cloudy days or early mornings.
On the Victorian Default Offer domestic flat tariff, from 1 July 2026 to 30 June 2027, it is $1.1912 a day in the United Energy zone, $1.2114 for CitiPower, $1.2713 for Jemena, $1.2824 for AusNet Services and $1.3805 for Powercor, including GST. Retailers’ market offers can be higher or lower. Your own supply charge is printed on your bill.
No. The supply charge is fixed per day by your retailer and does not depend on how much you use. A battery lowers the usage part of the bill. To lower the supply charge you need a plan with a lower one, which you can compare on Victorian Energy Compare.
It depends on your solar output, when you use power, the battery size and your plan. The customer in this article went from $3.37 a day to $1.17 a day, 65% lower than the same bill period a year earlier, while grid use fell 88%. That is one household’s result, not a forecast. A bill check is the way to estimate yours.
It is worth checking. Once a battery covers most of your evening use, the daily supply charge and the feed-in tariff matter more than the usage rate. A plan chosen for a home using 9 kWh a day from the grid may not be the best one for a home using 1 kWh a day.
Send us your latest electricity bill. We will look at your daily grid use, how much of it falls in the evening, your tariff and your supply charge, and tell you what size battery fits, which of this month’s packages suits your home, and whether a battery stacks up at all. If it does not, we will say so.
Book a free energy assessment or call 1300 254 507.
Pages checked on 14 October 2026. The percentage changes, yearly supply charge figures and plan comparisons are E3 Energy calculations from the bill and the published default offer tariffs. They are not a savings estimate for any particular home. Package prices apply to eligible homes and are confirmed in a written quote.
