Western Australia operates outside the National Electricity Market and the DMO does not apply. The electricity market in WA is split between the South West Interconnected System (SWIS), where Synergy is the dominant retailer, and the North West Interconnected System plus remote areas, where Horizon Power is the sole provider.
Retail competition in WA is limited compared to eastern states. For most residential customers, Synergy is the only available retailer. The state government sets regulated residential tariffs through the Economic Regulation Authority (ERA), and prices are partly subsidised through the Tariff Adjustment Payment.
Our take on electricity in Western Australia
WA is a unique market. Unlike the eastern states where you can shop around between 10 or more retailers, most WA households can only choose Synergy. That does not mean there is nothing to optimise. Synergy offers multiple tariff types including flat rate (A1), time-of-use (A3), and a midday TOU tariff (Midday Saver) that rewards daytime usage with rates as low as 9 cents per kWh between 9am and 3pm.
If you have solar panels, the Midday Saver tariff combined with Synergy's Distributed Energy Buyback Scheme (DEBS) rates can significantly reduce your annual costs. The DEBS rate is tiered: higher for exports between 3pm and 9pm, and lower for exports at other times.
For regional and remote WA on the Horizon Power network, prices are regulated and comparable to the SWIS through the Uniform Tariff Policy. Tariff options are more limited, but Horizon Power does offer TOU and solar buyback options in some areas.
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Compare plans nowElectricity networks in Western Australia
Western Power (SWIS)
Western Power operates the distribution network for the South West Interconnected System, covering Perth, the south-west, and the wheat belt. Most WA households are on this network with Synergy as their retailer. Synergy's regulated residential tariff (A1) is a flat rate, but the Midday Saver (A3) and other TOU options are available for customers with smart meters or interval meters.
Horizon Power (Regional and remote WA)
Horizon Power serves regional and remote Western Australia, from Esperance to Kununurra. It acts as both the network operator and the retailer. Prices are regulated and subsidised to maintain parity with the SWIS under the state's Uniform Tariff Policy. Horizon serves some of the most remote communities in Australia, including island and off-grid microgrids.
What would you pay? Real scenarios for WA households
Family of three in Perth (Western Power/Synergy, 5,000 kWh/year, ducted evaporative cooling, no solar)
On the Synergy A1 flat rate tariff: approximately $1,700 to $1,850 per year. Switching to the Midday Saver tariff and running major appliances during 9am to 3pm: approximately $1,450 to $1,600 per year. Potential saving: $200 to $250 per year from tariff optimisation alone.
Solar household in Perth (6.6kW system, 4,000 kWh/year grid consumption)
On the A1 flat rate with DEBS solar buyback: approximately $1,050 to $1,200 per year after solar credits. On the Midday Saver tariff: potentially $100 to $200 less, because the low midday rate reduces the value of self-consumption but the overall cost profile benefits households that export most of their solar and buy cheap midday power.
Tips for electricity in Western Australia
Check if the Midday Saver tariff suits you. Synergy's A3 tariff charges as low as 9 cents per kWh between 9am and 3pm, but higher rates apply during peak hours (3pm to 9pm). If you can shift usage to midday, the savings are substantial.
Solar is highly effective in WA. Perth has some of the highest solar irradiance of any Australian capital. The DEBS buyback scheme provides tiered feed-in rates, with higher rates for exports during the 3pm to 9pm peak window. Pairing solar with a battery to export during peak hours maximises the DEBS value.
WA electricity is subsidised. Residential tariffs in WA are partially subsidised by the state government through the Tariff Adjustment Payment. This means regulated prices do not fully reflect the cost of supply, which is why WA prices are lower than SA despite similar generation challenges.