Peak, Off-Peak and Shoulder Tariffs Explained for Australian Homes
If your electricity bill shows different rates for different times of day, you are on a time-of-use (TOU) tariff. Understanding when peak, shoulder and off-peak periods apply 鈥?and which appliances you run during each 鈥?can meaningfully reduce your electricity bill without spending anything.
- Time-of-use tariffs charge different rates at different times: peak (highest), shoulder (mid) and off-peak (lowest).
- Peak periods are typically weekday afternoons and evenings 鈥?3pm to 9pm.
- Off-peak is usually overnight and weekends.
- If you have solar, TOU tariffs interact with your self-consumption and export timing.
What a time-of-use tariff is
A time-of-use (TOU) tariff divides the day into periods with different electricity rates. The idea is that electricity costs more to supply during periods of high demand 鈥?when many households are running air conditioning, cooking and charging devices at the same time. Off-peak periods have lower wholesale electricity costs, so retailers pass through lower rates.
The three periods are:
Peak: The most expensive rate. Typically applies on weekday afternoons and evenings 鈥?the busiest period on the grid.
Shoulder: A mid-range rate. Applies in the transition between peak and off-peak, or on weekends in some plans.
Off-peak: The cheapest rate. Typically overnight, and often on weekends.
Typical TOU period times in Australia
Period times vary by retailer, network and state. These are common patterns 鈥?check your actual plan:
| Period | Typical times | Typical rate range |
|---|---|---|
| Peak | Mon鈥揊ri 3pm鈥?pm (some plans 2pm鈥?pm) | $0.35鈥?0.55/kWh |
| Shoulder | Mon鈥揊ri 7am鈥?pm and 9pm鈥?0pm, Sat鈥揝un 7am鈥?0pm | $0.20鈥?0.30/kWh |
| Off-peak | All other times (typically overnight 10pm鈥?am, all day Sunday on some plans) | $0.12鈥?0.22/kWh |
Flat rate vs time-of-use: which is better?
A flat rate tariff charges the same rate per kWh regardless of when you use power. Time-of-use is better for you if you can shift consumption to off-peak periods. It is worse if most of your usage falls during peak times.
TOU is likely better if:
- You are at home during the day and can run appliances then
- You have solar panels 鈥?daytime usage is often in the shoulder or off-peak period
- You can shift dishwasher, washing machine and dryer use to evenings or weekends
- You are on a controlled load hot water tariff (often a separate rate)
A flat rate is likely better if:
- Most of your household usage is in the 5pm鈥?pm window (cooking, air conditioning, TV)
- You cannot easily shift when you run high-draw appliances
- You work from home with high daytime usage that can't be shifted
How to use TOU tariffs to reduce your bill
The core strategy is simple: shift discretionary loads away from peak periods.
Appliances that are easy to shift:
- Dishwasher 鈥?run after 9pm or before 3pm
- Washing machine 鈥?run overnight or at weekends
- Clothes dryer 鈥?run off-peak
- Pool pump 鈥?if controllable, schedule to run during off-peak hours
- EV charging 鈥?schedule overnight charging via your car or charger app
Appliances that are harder to shift:
- Air conditioning during summer evenings 鈥?peak period use is hard to avoid
- Cooking 鈥?most households cook dinner during peak hours
- TV and entertainment 鈥?evenings are peak
Even shifting the dishwasher and washing machine to off-peak can save $80鈥?150 per year depending on how often you run them.
TOU tariffs and solar panels
If you have solar panels, the interaction with TOU pricing is important.
Solar generates during the day 鈥?mostly between 9am and 4pm. If you are on a TOU tariff:
- Daytime solar generation covers your shoulder-period usage (a saving at the shoulder rate)
- If your solar generates more than you use during the day, you export at the feed-in tariff rate
- You still pay peak rates for any electricity you import in the evening
This means:
- Running appliances during solar generation hours maximises self-consumption at shoulder rates
- A battery can store surplus daytime solar to cover evening peak-period usage 鈥?replacing peak-rate imports with stored solar
Controlled load tariffs
A controlled load (CL) tariff is a separate circuit and meter for hot water systems, pool pumps and similar high-draw appliances. The distributor controls when these loads switch on 鈥?typically overnight 鈥?at a reduced rate, often $0.10鈥?0.18/kWh.
If you have an electric storage hot water system and are not on a controlled load circuit, you are likely paying either flat or shoulder rates to heat water. Ask your retailer whether a controlled load connection is available.
How to check what tariff you are on
1. Look at your electricity bill 鈥?it should list the tariff structure and the rates for each period
2. Check your retailer's website for the current plan you are on
3. If you see only one rate listed for general usage, you are on a flat rate tariff
If you are unsure, call your retailer and ask specifically: "Am I on a flat rate or time-of-use tariff, and what are my current peak, shoulder and off-peak rates and times?"
Peak, shoulder and off-peak tariffs charge different rates at different times. Peak is typically weekday evenings 鈥?the most expensive period. The strategy is to shift discretionary loads (dishwasher, washing machine, EV charging) to off-peak or shoulder periods. If you have solar, maximise daytime use. A battery can cover evening peak usage with stored solar, converting your most expensive electricity imports into self-consumption.