How to Read Your Electricity Bill: The Lines That Quietly Cost You
Supply charge, usage, demand and the sneaky extras — what each line actually means, and where your money really goes.
Most people glance at the total, wince, and pay it. But your electricity bill is a detailed map of how you use power — and once you can read it, you can spot where your money leaks. This guide walks through every major line so you know exactly what you're paying for, and which charges quietly do the most damage.
The three big line types
Almost every bill breaks down into three cost categories. Get these straight and the rest falls into place.
1. Supply charge (the daily fixed fee)
This is a flat amount charged for every day you're connected, whether you use any power or not. It's shown in cents per day and multiplied by the number of days in the billing period. Because it's fixed, you can't reduce it by using less — the only lever is switching plans or retailers. For low-usage households (small units, holiday homes, or homes with lots of solar) the supply charge can be a surprisingly large slice of the total. Always compare it when shopping plans, because a cheap usage rate paired with a high daily supply charge can cost you more overall.
2. Usage charge (cents per kWh)
This is the variable part — you pay per kilowatt-hour (kWh) of electricity consumed. How it's priced depends on your tariff:
- Single/flat rate: one price per kWh, any time of day.
- Time-of-Use (TOU): different prices for peak, shoulder and off-peak periods. Peak is typically around 2–8pm (later in some states), which is confirmed from your actual bill. Running the dishwasher, dryer or pool pump during peak on a TOU plan is one of the most common quiet money-drains.
- Controlled load: a separate cheaper rate for dedicated circuits like an electric hot water tank, metered independently.
3. Demand charge (the one people miss)
This is where bills get sneaky. A demand charge bills you not for how much you use, but for your highest rate of use in a given window — usually your single worst 30-minute peak in the month, measured in kW. Turn on the oven, aircon, kettle and dryer at 6pm and you set a high demand figure that gets charged for the whole billing period, even if it happened once. Demand tariffs are increasingly common on homes with smart meters and on many small-business accounts.
Watch this line. If your bill has a "demand" or "capacity" charge in kW, spreading big appliances out — rather than all at once — can cut it noticeably, without using a single kWh less. Many households don't realise they're even on a demand tariff until they read the fine print.
The credits and smaller lines
These lines can work for or against you:
- Feed-in tariff (FiT): the credit you earn for solar exported to the grid. It's retailer-set and falling in most states, with typical rates roughly in the 3–10 c/kWh range; Victoria, regional Queensland and Tasmania set a regulated minimum. Confirm the current rate for your state — a headline-grabbing FiT often comes bundled with a higher usage rate, so the "generous" plan can cost you more overall.
- Solar Sharer free-power window: a federal offer live from 1 July 2026 via participating retailers, giving eligible opt-in customers free grid power in an 11am–2pm window, capped at 24 kWh a day, if you have a smart meter. Availability varies by retailer and state — confirm whether it's on your plan.
- Discounts and conditions: pay-on-time or direct-debit discounts appear as credits — but check what you lose if you miss the date.
- Metering charges, membership fees, environmental levies: small recurring lines that add up across a year. Read them; don't assume they're fixed and unavoidable.
How to actually work out where your money goes
Do this once and you'll never read a bill blindly again:
- Add up the supply charge for the period (cents/day × days). That's your fixed base.
- Total the usage charges and note whether they're flat or split by peak/off-peak.
- Find any demand charge and note the kW figure and when your peak was set.
- Subtract feed-in credits and discounts.
- Check the average daily usage graph most bills print — compare it to the same period last year to spot creep.
Once you can see the split, the fixes become obvious: high supply charge means shop the plan; high peak usage means shift the timing; a demand line means stop stacking appliances at once.
Here's the catch
The single biggest mistake is chasing one headline number — a low usage rate, or a high feed-in tariff — without checking the others. Retailers know which line you'll notice and which you won't. A plan with a shiny 10c feed-in rate but a steep peak usage charge and a high daily supply fee can leave a solar household worse off than a duller-looking plan. And moving to solar or a battery only pays if your bill structure actually rewards it — for some households on the wrong tariff, or with low daytime use, the numbers simply don't stack up. The only way to know is to read your own bill, in full, against your own habits.
We don't sell power plans, solar or batteries — so we've got no reason to steer you toward the line that pays us. Our job is to read your actual bill against your actual usage and tell you the truth, even when the truth is "your current plan is fine, don't change a thing."
Want to know what actually pays for your place?
Get an independent, engineered read on your whole bill — solar, battery, tariff and the rebates you're really entitled to — for a small fixed fee. No system to sell, no sales call.
Start your audit — $100Figures in this guide are current at the date of publication and indicative only — rebate and certificate values change over time (federal battery certificates step down each January and July), and state schemes are amended often. Confirm the current numbers for your situation before you commit. This is general information, not personal financial advice.