The two ways you can be charged for power
Almost every electricity plan uses one of two structures for your usage. A single-rate (also called flat-rate or anytime) tariff charges the same price per kWh no matter when you use it — 2pm on a Tuesday costs the same as 2am on a Sunday. It is simple and predictable.
A time-of-use (TOU) tariff splits the day into periods and charges a different rate for each. Peak is the expensive window (typically weekday late afternoon and evening, when the grid is busiest), off-peak is the cheapest (usually overnight), and shoulder covers the times in between. The exact hours are set by your local network, not just your retailer, so they vary by state and area.
Which one is cheaper for you?
There is no universal winner — it depends entirely on when you use power. Time-of-use rewards households that can shift big loads into the off-peak window. If you run the dishwasher and washing machine overnight, charge an EV after midnight, heat water on a timer, or have a home battery, TOU can be meaningfully cheaper because a large share of your kWh land in the cheapest period.
Single-rate usually wins for households whose usage clusters in the peak window and cannot easily move — for example, someone home all afternoon running heating or cooling, with no way to shift that load. On a TOU plan those same kWh would be charged at the highest rate, wiping out any off-peak savings.
The catch is that you often cannot know just by reading the rates. The peak rate on a TOU plan can be much higher than a flat rate, while the off-peak rate is much lower. Whether the trade nets out cheaper depends on the exact split of your kWh across the day — something you cannot eyeball from a summary bill.
How to compare them properly
- Check which tariff you are on now — it is printed on your bill, and your meter type partly determines what you are eligible for (TOU generally needs a smart meter).
- Get a sense of when you use power. A smart meter records interval data; some retailers show a usage-by-time breakdown in their app or portal.
- Do not compare on headline rates alone. Cost the same usage against both structures — the only way to see which is actually cheaper for your pattern.
- Upload a recent bill to EnergySorted so both tariff types are costed on your real peak, shoulder and off-peak split at once, across every retailer, not just the two your current retailer offers.
Key terms
- Peak
- The most expensive TOU period, usually weekday late afternoon and evening when grid demand is highest.
- Off-peak
- The cheapest period, typically overnight and sometimes weekends — the window to shift big loads into.
- Shoulder
- The middle-priced period that fills the gaps between peak and off-peak.
- Smart meter
- A digital meter that records usage in intervals, making time-of-use billing possible. Being rolled out across most of the NEM.
- Load shifting
- Deliberately running appliances during cheaper periods — the behaviour that makes TOU pay off.