If your bill has a second usage line at a much cheaper rate, congratulations: you probably have a controlled load. It is one of the oldest tricks in the Australian electricity system, and it is still one of the best, but it confuses plan comparisons more than almost anything else.
What a controlled load is
A controlled load is an appliance, most commonly an electric hot water system, wired to a separately metered circuit that the network can switch on and off. Because the network controls when it runs, usually overnight or in other off-peak windows, the electricity it uses is billed at a cheaper rate than your general usage.
The classic example is an electric storage hot water system that heats the tank overnight and holds the hot water through the day. Slab and underfloor heating and pool pumps are other common candidates.
The trade-off is availability: a controlled load circuit is only energised for a limited number of hours a day, in windows the network picks. That is fine for a storage tank, and useless for a toaster.
Why the name on your bill varies
Every State grew its own naming, which is why the same idea looks different on bills around the country:
- Queensland: commonly Control Load 1 and Control Load 2 (historically Tariff 31 and Tariff 33). CL1 typically gets fewer supply hours than CL2 and is priced accordingly.
- New South Wales and the ACT: Controlled Load 1 and Controlled Load 2, same idea.
- South Australia: usually a single controlled load option.
- Tasmania: tariff numbers are the norm, with Tariff 41 the one commonly used for heating and hot water.
- Victoria: often called a dedicated circuit rather than a controlled load.
- Western Australia and the Northern Territory: separately metered off-peak circuits exist but household pricing is government-set, so there is less plan-to-plan variation to compare.
How to tell if you have one
Look at the usage section of your bill. If there is a second usage line with its own kWh figure and a cheaper rate, labelled with any of the names above, you have a controlled load. Its usage is metered separately, so the kWh on that line are already excluded from your general usage line.
If your hot water is gas, solar or a heat pump on your normal circuit, and you have no slab heating or separately wired pool pump, you most likely do not have one, and you can simply enter zero for controlled load when comparing.
Comparing plans when you have a controlled load
Here is where comparisons go wrong. A plan with a brilliant general usage rate can still lose overall if its controlled load rate is poor, and some plans do not publish a controlled load rate at all.
Our free calculator handles this the honest way. You enter your general usage and your controlled load usage separately, and every plan is costed on both. If an imported plan does not publish a controlled load rate, the calculator bills your controlled load usage at that plan's general rate and tags the plan so you can see the assumption. That keeps every plan on the list comparable instead of quietly ignoring part of your bill.
To see it with your own numbers, grab a recent bill, note your average daily usage and your controlled load's daily kWh, and pick your State. In Queensland, New South Wales, Victoria, South Australia, Tasmania and the ACT you can import real plans for your postcode from government data; everywhere else the manual calculator does the same maths.
Is a controlled load still worth it?
Usually yes, if you already have the wiring and a storage hot water system: the cheaper rate does real work on a big chunk of your usage. Whether to add one is a different question involving an electrician, your meter and how you use hot water, and if you are considering a heat pump or solar diverter instead, the answer changes again. For choosing between retailers, though, the rule is simple: if you have a controlled load, never compare plans on the general rate alone.