What is a controlled load?

Some appliances, such as hot water heaters, consume huge amounts of energy compared to others. Luckily, they don't need to be powered constantly to function. This allows them to benefit from something known as a controlled load tariff.

You may already be using a controlled load tariff on your power plan, but if you aren't, it's possible that one could help save you money. Read on to find out what a controlled load tariff is and how it can benefit you.

What is a controlled load tariff?

A controlled load tariff is a type of energy tariff that's used for appliances that consume high amounts of energy, most commonly heating systems or hot water systems. This is how a controlled load tariff works:

• The appliance is run and metered its own dedicated circuit, which allows for separate billing.
• Power used on the controlled load circuit will generally be billed at a different, lower rate compared to your general electricity usage.
• Electricity will only be supplied to your controlled appliance for a set number of hours per day, depending on what kind of controlled load it is. Usually, this is during off-peak hours or overnight.
• A controlled load may attract its own separate supply charge of a few cents per day on some distribution networks.

A controlled load tariff usually exists as part of a regular energy plan, whether you use a single rate, time of use tariff or something else for the rest of your power usage.

Am I on a controlled load scheme?

There's a good chance that you're on a controlled load scheme if you have a dedicated heating appliance such as:

• An electric hot water heater
• Underfloor heating
• A heated swimming pool

The easiest way to see whether or not you have an active controlled load tariff is to look at the usage breakdown on your energy bill. Your controlled load may appear as "off-peak", "controlled load", or tariff 31, 33, 61 or 63, depending on what state you live in.

Alternatively, contact your energy retailer, which should be able to give you the details of your current plan.

How can I get on a controlled load tariff if I'm not already?

If you have an existing device or are installing a new device that you think would work well with a controlled load tariff, here's what you should do:

1. Choose an energy retailer. You can contact your current energy retailer and see if they're able to add on a controlled load tariff to your existing plan or switch you over to another plan that does support it. Alternatively, you can compare plans online to find a new one that supports a controlled load with good rates.
2. Fix your metering. Your existing device may or may not already have a dedicated meter attached to it. Either way, your retailer will advise you as to whether you need to change your metering set-up to support the tariff, which can cost additional money.

Will a controlled load tariff save you money?

While this depends on your exact circumstances and the appliances involved, in general, a controlled load tariff will save you money. Heating water, for example, is an extremely energy-intensive process, so being able to heat that water at a much lower rate than you would normally pay can save you money in the long run.

The biggest costs associated with controlled loads are:

• The initial outlay to set up the proper metering for the tariff.
• The potential daily supply charge added on for the controlled load circuit.

If these costs are outweighed by how much you save on usage costs, you should save money overall.

Controlled load 1 versus controlled load 2

The major difference between controlled load 1 tariffs and controlled load 2 tariffs are the restrictions they place on when your controlled load circuit can use power, as well as the usage rates involved. Remember that these tariffs may be called something else depending on your retailer, and they're only available in New South Wales and Queensland.

Here's how the two compare:

What is a tariff 33 controlled load?

Tariff 33 is the Queensland equivalent of a Controlled Load 2. It offers a longer minimum period over which electricity is available for your controlled load circuit, but charges higher usage rates than Tariff 31 (the equivalent of a Controlled Load 1 tariff).

What issues might I run into with a controlled load?

A lot of the potential issues with controlled load circuits arise when you have or install solar power. This also depends on your energy distributor and its policies. Here are a couple of examples:

• Loss of controlled load. There have been cases where certain distributors (e.g., United Energy in Victoria) have not allowed customers to receive solar feed-in tariffs at the same time as running a controlled load. Check before installing solar power that you'll be able to keep your controlled load tariff after the upgrade.
• Paying for your own solar energy. Some distributors have switched to turning on controlled load circuits for heating water from overnight to the middle of the day when the most solar energy is available. But if you're using your own solar power for this heating, the energy going into the controlled load circuit may still be counted as consumption (attracting its regular usage charge). In this way, you're paying to use your own solar power.

It seems that some of these issues have arisen from several distributors that are trying to phase out controlled load tariffs in the long term. Check with your own distributor to see how a controlled load might work with a solar set up.