Cart
0
Swell Sport · Practical guide
Budgeting sauna use on an electricity plan with demand charges
Demand tariffs make overlapping loads important. Start with the actual charging rule, then use a simultaneous-load diary to understand the sauna’s place in the bill.
Request the rule behind the demand figure
Ask the retailer which window applies, how demand is averaged, which days count, the billing units and how long a maximum remains relevant. Ask about minimums and seasonal changes. Government guidance says demand tariffs take different forms, including monthly or annual maxima and maxima confined to peak periods. [1]
An instantaneous app spike may not be the figure used for billing. Request the interval data or bill field that establishes the charge. A low daily kWh average does not answer this question either: the enquiry concerns a qualifying maximum, not simply energy accumulated across the day.
Make a timeline, not a stress test
For the relevant window, note sauna heating, charging, cooking, space conditioning and other substantial loads that actually operated. Add solar output or battery operation only where data supports it. Capture the diary at the time rather than asking everyone to reconstruct an entire month later.
Do not deliberately switch everything on to test the home. The diary describes usage; it does not assess electrical capacity. Give proposed circuit or load-management changes to an electrician. In Victoria, electrical installation work is specifically directed through a registered electrical contractor. [2]
Illustrate one possible demand rule
Suppose an invented plan charges $0.18 per kW per day against one qualifying maximum for a 30-day bill. Raising that maximum from 5 kW to 9 kW changes this component by (9 − 5) × $0.18 × 30 = $21.60. That is arithmetic for the stated hypothetical contract, not a current offer or a household prediction.
It does not mean each heating cycle adds $21.60. If an earlier event already set the higher maximum, another cycle below it may not change that component. Rearranging tomorrow’s routine also may not undo a maximum already established. Use the actual contract before attributing the charge to the sauna.
Agree a practical coordination rule
Once the retailer has explained the data, look for controllable overlaps inside the relevant window. Discuss scheduling discretionary loads without overriding essential needs or equipment safeguards. A lower graph is not a reason to bypass a sauna controller, ignore a fault or keep someone inside beyond their own comfortable limit.
Write a simple household rule, such as checking the planned vehicle-charging period before choosing a sauna start. Compare the next bill’s qualifying maximum with the diary and note other changes. Report an observed difference without calling it a permanent saving: household activity, tariffs and solar conditions may differ. Keep powered-cycle timing separate from personal bathing duration throughout the exercise.
Your practical checklist
- Confirm demand units, averaging and qualifying windows.
- Get the data that actually set the bill.
- Log overlaps without deliberately loading the supply.
- Check whether an earlier maximum still applies.
Will shorter sauna use remove demand charges?
Not necessarily. A short cycle can still overlap the interval that sets the maximum. Duration alone is not the billing rule.
Can I assign the whole demand charge to the sauna?
Only if the evidence supports that allocation. Examine the baseline and simultaneous loads rather than blaming the newest appliance.
