Business energy guides
Does your electricity plan suit your trading hours?
A flat-rate tariff uses one general usage price across the day. A time-of-use tariff applies different usage prices in defined periods. Which costs less depends on when your business uses electricity as well as the rates and other charges.
By the Check Your Energy Bill team · Updated
Check my business billWhen you use power changes the result
Same 1,000 kWh. Example rates: 40c peak and 20c off-peak.
More peak usage
600 kWh peak · 400 off-peak
$320usage costMore off-peak usage
400 kWh peak · 600 off-peak
$280usage costFictional usage prices including GST. Supply, demand and other charges excluded. Flat-rate usage at 30c/kWh would cost $300. These are not offers.
How the tariff structures differ
With a flat rate, multiply general usage by the applicable single usage price. A time-of-use calculation splits usage between the plan’s pricing periods. Supply charges still need to be included.
Peak, shoulder and off-peak times vary by plan, network, day and sometimes season. Some plans do not have all three periods. Use the schedule attached to the actual offer.
Compare the same usage profile
A shop trading mainly in daytime hours can have a different cost pattern from a restaurant trading into the evening. Use meter interval data or the billed usage split rather than guessing from opening hours alone.
Refrigeration, cleaning and other equipment may run outside trading hours. Include those loads when deciding how much consumption falls into each period.
A worked comparison
Suppose monthly usage is 1,000 kWh. At a flat 30 cents/kWh, usage costs $300. At illustrative time-of-use rates of 40 cents peak and 20 cents off-peak, a 600/400 kWh split costs $320.
With a 400/600 kWh split at those same example rates, usage costs $280. These figures exclude supply, demand and other charges and are not offers. The result changes with the usage split.
Check metering and demand charges
Ask whether your meter and site are eligible for the offer and whether a tariff change has conditions or costs. Some time-of-use offers also include a separate demand component.
Our automated usage-and-supply shortlist does not fully model time-of-use patterns or demand charges. Ask for a complete assessment before treating a shortlist estimate as the final cost for a complex tariff.
Choose a plan your business can operate with
Only count a change in operating hours if it is practical, safe and realistic for the team. A plan that looks cheap with overnight usage may not suit a business whose equipment must run at peak times.
Compare annual costs using the same usage data and GST basis, check the full terms and keep the accepted schedule. Revisit the choice if trading hours or equipment change.
Sources and further reading
Sources checked 26 October 2026. Rates and eligibility can change. Your comparison shows its own data verification date.
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