Controlled Load Tariff Explained: What Australian Homeowners Should Know

If you’ve ever looked closely at your electricity bill and spotted a line labelled “Controlled Load 1” or “Tariff 31” sitting separately from your usual usage charges, you’re one of the roughly half a million Australian households already on a controlled load tariff. It’s one of the least understood parts of a power bill, yet for homes with an electric hot water system, it’s often the single biggest lever for cutting costs.

A controlled load tariff is a discounted electricity rate for specific high-energy appliances, usually hot water systems, that run on their own dedicated circuit and are switched on and off by your network distributor rather than by you. It sits alongside your normal household tariff, not instead of it. In August 2026, with solar households growing and EV charging becoming more common, understanding how these tariffs actually work matters more than ever.

What is a controlled load tariff

A controlled load tariff, sometimes called a dedicated circuit tariff, applies to one or two specific appliances in your home that use a lot of energy but don’t need power around the clock. The classic example is an electric storage hot water system: it heats a large tank of water during a set window each day, then holds that heat for hours afterward, so it doesn’t actually need to be powered continuously.

Because these appliances can tolerate having their power supply switched on only at certain times, network distributors offer a much lower rate in exchange for controlling exactly when that happens. This is different to a standard flat tariff, which charges the same rate all day, and different again to a time-of-use tariff, which changes your rate depending on the time of day but still leaves the appliance running whenever you use it. With a controlled load, the distributor, not you or your retailer, decides the switching times.

Other appliances commonly run on a controlled load include pool pumps, underfloor or slab heating, and increasingly EV chargers, where permitted by the local network.

Controlled load 1 vs controlled load 2: what’s the difference

In states where more than one option exists, most commonly New South Wales, Queensland, the ACT and Tasmania, you’ll typically see two variants, often labelled Controlled Load 1 and Controlled Load 2 (or CL1 and CL2), though Queensland and Tasmania use different tariff numbers for the same concept.

Controlled Load 1 (CL1): This is usually the cheaper of the two options, but it comes with a shorter supply window, often a single overnight block of around six to nine hours. It suits smaller households with modest hot water needs, since the tank only gets one heating window per day.

Controlled Load 2 (CL2): This tariff costs a little more per kilowatt hour, but the supply window is much longer, sometimes up to 16 to 19 hours across a 24-hour period, and can include a block of daytime hours as well as overnight. This suits larger households, bigger storage tanks, or appliances like pool pumps and underfloor heating that benefit from more flexible run times.

The trade-off is essentially hours versus price. If your hot water regularly runs out by evening on CL1, that’s usually not a sign the system is faulty, it’s a sign the tank isn’t getting enough hours in its heating window, and CL2 (or a larger tank) may be the better fit.

What controlled load tariffs are called around Australia

The underlying concept is the same everywhere, but the naming varies significantly by state and network, which is part of why so many homeowners find the topic confusing.

• New South Wales: Controlled Load 1 and Controlled Load 2 (CL1 and CL2) are the standard terms used by most networks and retailers.
• Queensland: Referred to as Tariff 31 (shorter, overnight) and Tariff 33 (longer, including daytime hours).
• Tasmania: Uses Tariff 61 and Tariff 63, following a similar overnight-versus-extended-hours structure.
• Victoria and South Australia: Typically only one controlled load option is offered, rather than a CL1/CL2 style split, though the general concept of a separately metered, distributor-switched circuit still applies.
• Western Australia: Synergy customers may see this referred to as an “Economy” tariff. Because WA doesn’t have retail electricity competition in the way the eastern states do, options and switching times are set centrally rather than varying by retailer.

Whatever it’s called on your bill, the giveaway is usually a separate line item with its own rate, plus a small additional daily supply charge for the second meter or circuit.

Off-peak hot water in Australia: the most common use case

For most households, “controlled load” and “off-peak hot water” are effectively the same thing, since hot water heating is by far the most common appliance run this way. Historically, off-peak hot water ran purely overnight, when overall demand on the grid was lowest and generation (mostly coal-fired at the time) was cheapest to keep running.

That’s been changing. As rooftop solar has grown across Australia, daytime electricity supply is now often the cheapest and most abundant time of day rather than overnight, particularly around midday. In response, several networks, including Ausgrid in New South Wales, have progressively shifted controlled load switching times to include a daytime block as well as, or instead of, the old overnight-only window. This is especially relevant for households with rooftop solar, since a daytime switching window means your electric hot water system can be timed to draw from cheap grid-supplied off-peak power in the middle of the day, when demand and wholesale prices are typically at their lowest.

It’s worth noting that a hot water system on a controlled load is not the same as a system powered directly by your own rooftop solar. Even with a daytime switching window, the appliance is still drawing metered grid electricity at the controlled load rate, not your home’s solar generation, unless you’ve set up additional equipment like a solar diverter.

How controlled load tariffs interact with solar and batteries

This is where a lot of solar and battery owners get caught out. Because a controlled load appliance is on its own dedicated circuit, separately metered and switched by the network distributor, it generally can’t draw on your rooftop solar generation or your home battery in the normal sense. Your solar system and battery are typically connected to your main household circuit, while the controlled load appliance sits on a physically separate wiring path designed specifically so the network can control it independently.

In practice, this means:

• Solar owners often assume their free daytime solar power is heating their hot water, when in fact it’s still being billed at the controlled load rate for grid electricity, unless the switching window happens to overlap with your solar export and you’ve specifically arranged for the appliance to draw from your own generation via a diverter or similar device.
• Battery owners usually can’t use stored battery power to run a controlled load appliance either, for the same reason. The appliance is wired to draw from the grid at set times, not from whatever circuit your battery happens to be backing up.
• Some newer, more integrated battery and home energy systems are starting to offer ways to bridge this gap, but as a general rule in 2026, don’t assume a controlled load appliance is automatically included in your solar or battery savings.

None of this makes a controlled load tariff a bad choice for solar and battery households; the discounted rate can still be worthwhile. It just means the appliance sits somewhat separately from the rest of your home energy strategy, rather than being folded into it automatically.

Is a controlled load tariff still worth it in 2026

For most households with an electric storage hot water system, yes. Controlled load rates are still typically 30 to 50 per cent cheaper than a standard or peak usage rate, and since hot water is usually one of the largest single loads in an Australian home, keeping it on the lower rate can meaningfully reduce your quarterly bill.

The main scenarios where it’s worth reconsidering are:

• You have a large solar system and want to prioritise self-consumption over the cheapest possible flat rate, in which case a timer or diverter-based approach may suit you better, even if it’s not quite as cheap per kilowatt hour.
• You’re in Western Australia, where controlled load style tariffs continue to be phased down over time in some areas, so it’s worth checking directly with Synergy about current availability and future plans for your connection.
• Your household size or hot water habits have changed and you’re regularly running out of hot water on CL1, where switching to CL2 or upgrading tank size is usually a simpler fix than removing the controlled load altogether.

How to check your tariff and get set up

If you’re not sure whether you already have a controlled load tariff, there are a few ways to check:

1. Look at your electricity bill. Controlled load usage is almost always listed as a separate line item, with its own rate and small daily supply charge, usually on the second page.
2. Check your meter box. A dedicated controlled load setup typically has a visibly separate circuit or sub-meter for the appliance in question.
3. Call your retailer. They can confirm your current tariff structure and advise whether alternative controlled load options are available in your network area.

If you don’t currently have one and think you’d benefit, setting one up (or changing between CL1 and CL2) generally requires a licensed electrician to install or adjust the dedicated circuit, along with your retailer updating your billing tariff. It’s not something you can do yourself, but for most homes it’s a straightforward job rather than a major rewiring project.

FAQs

What is a controlled load tariff in Australia It’s a discounted electricity rate for specific high-energy appliances, usually hot water systems, that run on a separately metered circuit switched on and off by your network distributor at set times, rather than continuously like the rest of your home.

What’s the difference between controlled load 1 and controlled load 2? Controlled Load 1 is typically cheaper but supplies power for fewer hours, often overnight only. Controlled Load 2 costs a little more but supplies power for longer, sometimes including daytime hours, suiting larger households or bigger appliances.

Can I use solar power to run an appliance on a controlled load tariff? Generally not directly, since controlled load appliances are wired on a separate circuit from your main solar and battery system. Your hot water system will still draw grid electricity at the controlled load rate unless you install a solar diverter or similar equipment.

Is off-peak hot water the same as a controlled load tariff? Largely yes. Off-peak hot water is the most common use of a controlled load tariff, though the switching times have shifted in many networks to include daytime hours as well as overnight, to make better use of solar generation across the grid.

How do I know if I already have a controlled load tariff? Check the second page of your electricity bill for a line item such as “Controlled Load,” “Dedicated Circuit,” or a tariff code like Tariff 31 or Tariff 61. Your retailer can also confirm this and explain what options are available in your area.

Key Takeaways

• A controlled load tariff offers a discounted electricity rate for appliances like hot water systems, in exchange for the network distributor controlling when they’re powered.
• Controlled Load 1 is cheaper but runs for fewer hours, usually overnight, while Controlled Load 2 costs slightly more but runs for longer, often including daytime hours.
• Naming varies by state, from CL1/CL2 in New South Wales to Tariff 31/33 in Queensland and Tariff 61/63 in Tasmania, but the underlying concept is the same.
• Solar and battery owners should be aware that controlled load appliances are usually wired separately and don’t automatically draw on rooftop solar or battery power.
• For most households, a controlled load tariff for hot water remains worthwhile in 2026, though it’s worth reviewing if you’re prioritising solar self-consumption or running out of hot water regularly.

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