Electricity basics
Is It Cheaper to Run Appliances at Night?
Check if your tariff makes nighttime use cheaper. Calculate appliance savings from cycle kWh and rate differences, including cycles crossing price windows.
Only a tariff with different prices by time can make the same kWh cheaper at night. On a flat rate, timing alone changes nothing. Check your supplier's exact schedule.
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Running a dishwasher at night is not automatically cheaper. Your tariff determines whether electricity has different prices at different times.
The NSW Government's tariff guidance distinguishes flat-rate and time-of-use pricing. A flat-rate plan charges the same unit price throughout the day. Your own supplier's current plan remains the relevant source.
Confirm that your rate varies by time
Find the plan name on your bill and its current tariff schedule. Record peak, shoulder, and off-peak periods if they exist. Check seasonal, weekend, and holiday rules.
Do not assume “off-peak” always means a specific nighttime window. Some tariffs have low-price daytime periods. The supplier defines the hours and their effective dates.
The EIA notes that it does not publish individual utility tariff schedules. Use the supplier's documents or ask it to clarify an unclear bill.
Calculate the same energy at two prices
Use saving = kWh moved × (higher rate − lower rate). Energy use must be the same for this price-only comparison.
Suppose a hypothetical complete cycle uses 1 kWh. At an illustrative peak rate of $0.30/kWh, it costs $0.30. At $0.15/kWh, it costs $0.15. Twenty fully shifted cycles save $3.
If both rates are $0.20/kWh, the same shift saves $0. The time on the clock does not create a discount. These example rates are not current tariff offers.
Price cycles that cross a boundary
A long Eco cycle may begin off-peak and finish during another period. Do not apply the start-time price to all its energy unless the tariff explicitly works that way.
Suppose a hypothetical cycle uses 0.6 kWh at $0.15 and 0.4 kWh at $0.30. Total electricity cost is $0.09 + $0.12 = $0.21.
Energy may not be distributed evenly through the program. Use suitable interval data if available. If the split is unknown, describe it as uncertain instead of inventing a precise hourly profile.
Keep appliance safety and supervision
Use delay settings only as the appliance's instructions permit. Do not run a dryer or portable heater unattended solely to seek a lower rate.
For portable heaters, the CPSC specifies direct-wall use and turning them off while sleeping. A cheap time window does not remove those requirements.
Consider disturbance, leak precautions, and the complete finish time where relevant. Saving a small electricity amount is only one part of a household schedule.
Separate shifting use from switching plans
Moving one appliance within an existing plan is different from choosing a new tariff. A new plan can change the cost of other household use and fixed charges.
- Confirm the existing plan and exact price windows.
- Find complete-cycle or interval energy.
- Identify how much energy can actually move.
- Compare that energy at both applicable rates.
- Check total household costs separately before changing plans.
Use the time-of-use calculator for the entered energy shift. It does not decide whether a whole tariff switch saves money.
Sources
Source pages checked during research on 7 October 2026. Examples are Handy Daily calculations unless stated otherwise.