Perth Electricity Prices Compared

Households in Western Australia may not have a choice of electricity provider, but that doesn’t mean you don’t have a choice of electricity tariff.

Synergy, as the only electricity supplier for residential customers in the Perth area, provides either a ‘single rate’ or ‘flexible pricing’ option. This means that, depending on your energy usage habits, a change of tariff could deliver savings on your power bills. In this article, we explain the difference between these two tariffs and offer a guide as to which may be the best bet for your household budget.

Your Electricity Retailer… Synergy

South West Interconnected System

If you live in the south west corner of Western Australia, then your home will be connected to the South West Interconnected System – the electricity distribution network that supplies residential customers from Albany to Kalbarri, including metropolitan Perth. In this area, Synergy is currently the only authorised electricity retailer and there is no opportunity to switch. The prices that Synergy charges for power are regulated by the WA government.

The governing Labor party in WA does broadly support the deregulation of the electricity market, so one day things could change. But for now, you have to make the best of the situation with Synergy. It’s a similar story in regional WA, with Horizon Power the sole electricity supplier. The gas market in WA is also still regulated, but there are five different gas suppliers to choose from, which is proving good for competition.

While there is no electricity competition in the Perth area, there are at least two different electricity tariffs to pick from, resulting in different usage rates and varying overall energy costs. Picking the right tariff for your household’s needs is crucial to reducing your bills.

Synergy Home Plan (A1) Tariff

This is Synergy’s single rate tariff for households in the Perth area. With this tariff, households are charged the same electricity usage rate regardless of the time of day they use energy. Usage and supply charges are as follows:

Charge Price (Inc GST)
Supply Charge 105.1400 cents per day
Electricity Usage 29.3273 cents per unit

Source: Synergy website, April 2022

Synergy describes this tariff as its most simple and says it will result in easy to understand bills.

Synergy Smart Home Plan Tariff

This is Synergy’s flexible pricing, or ‘time of use’, tariff for households in Perth and the surrounding areas. With it, customers are charged different electricity usage rates depending on the time of day they use power. The usages times are split into three categories – peak, off-peak & ‘shoulder’ (the time between peak and off-peak) – and rates vary significantly.

Charge Price (Inc GST)
Supply Charge 105.1400 cents per day
Peak Electricity Usage 55.7734 cents per unit
Everyday Off-Peak Electricity Usage 15.3645 cents per unit
Weekday Shoulder Electricity Usage 29.2100 cents per unit
Weekend Shoulder Electricity Usage 29.2100 cents per unit

Source: Synergy website, April 2022

While the daily supply charge with Synergy’s time of use tariff is the same as its single rate plan, you can see how dramatically usage charges vary, from as low as 15.3645c per kWh to as high as 55.7734c per kWh.

  • Peak usage rates apply between 3pm and 9pm weekdays
  • Everyday off-peak rates apply between 9pm and 7am every day of the week
  • Weekday shoulder rates apply between 7am and 3pm Monday to Friday
  • Weekend shoulder rates apply between 7am and 9pm Saturdays and Sundays

Households must have a smart meter installed to access Synergy’s time of use electricity tariff.

Which Synergy tariff is right for me?

Synergy tariffs

Working out which of these two Synergy electricity tariffs will be cheaper for your household is no easy task. Usage rates with the Smart Home Tariff come in noticeably cheaper than usage rates on the A1 Tariff during off-peak times, but there is minimal difference between A1 Tariff rates and shoulder charges on the time of use plan. Peak time prices on the Home Smart Tariff are close to double those of the A1 Tariff.

So what does all this mean? It means that choosing the product best for your circumstances comes down to when you use power – and how much you use. To offer a guide as to which Synergy tariff works out the cheapest overall, Canstar Blue has done the number crunching. Based on varying assumptions around peak, off-peak and shoulder time electricity usage, the following table shows expected annual bills for typical households in the Perth area on the time of use tariff. We also show expected costs for households on the single rate tariff.

  • To do this, we assume in time of use example 1 that a household uses 40% of its energy at peak times, 30% at off-peak times and 30% at shoulder periods.
  • In time of use example 2, we assume that a household uses 30% of its energy at peak times, 40% during off-peak times and 30% at shoulder periods.
  • In time of use example 3, we assume that a household uses 30% of its energy at peak times, 30% during off-peak hours and 40% during shoulder periods.

We found that, based on the above assumptions, households on the single rate tariff would be better off in all three cases – more than $400 a year in one case. The following table shows annual costs for a household on the Synergy single rate tariff, plus all three time of use examples.

Tariff Type Annual Electricity Costs
Single Rate $2,524
TOU Example 1 $2,988
TOU Example 2 $2,693
TOU Example 3 $2,794

General guide only. Calculations based on daily electricity usage of 20 units. Weekend usage assumes 30% off-peak, 70% shoulder. April 2022.

We found that the single rate tariff works out to be the cheapest option in terms of annual electricity costs. Households would have to reduce their peak time energy usage significantly before the time of use tariff would become the cheaper option. However, this is a rough guide only, so if you use most energy during off-peak hours, it’s worth talking to Synergy about your options.

Is the Synergy time of use tariff worth it?

If you’re able to shift the vast majority of your daily electricity requirements to off-peak hours, the time of use tariff could deliver modest savings. However, it seems unlikely that anyone but shift workers who are not at home in the early hours of the evening would be able to achieve this. If you don’t think reducing your peak time energy usage to less than 20 per cent of your total consumption is a realistic proposition, the time of use tariff is probably not right for you.

The risk would be that a household switches to the time of use tariff but does not manage to significantly change its energy usage habits. As the table above shows, overall costs increase significantly when you use more electricity at peak times. With this in mind, customers considering the time of use option should have a good understanding of their energy requirements and also think carefully about how their usage habits might change over time before signing up.

What about gas in Perth?

Unlike electricity, customers in Perth do have some flexibility around their choice for natural gas plans.

Here are some of the cheapest gas deals on our database for WA. These estimated annual costs are based on the ATCO Network in Perth and yearly gas usage of 27,620 (units), but prices may vary depending on your circumstances. We show one product per retailer, listed in order of lowest estimated cost. These are products from referral partners†. Our database may not cover all deals in your area, and please check retailer websites for up to date information.

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