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Perth is different. Unlike the eastern states, WA's electricity market is dominated by state-owned Synergy — but recent reforms have opened limited retail competition. Here is what actually matters for your bill.
The South West Interconnected System (SWIS) covers Perth and the south-west. For residential customers, Synergy is the default and dominant retailer with about 80% market share. The WA Government sets Synergy's tariffs through the state budget. As of June 2026, the standard Synergy Home Plan (A1 tariff) is 30.8c/kWh with a daily supply charge of 109.8c. For a household using 4,800 kWh/year, that works out to about $1,879.
Limited competition started in 2024 with the WA Government's Electricity Retail Competition pilot. Currently, about 15% of Perth households can choose an alternative retailer including Alinta Energy, Kleenheat, and Synergy's own market plans. If you are in a contestable area, switching can save $150-250/year. If you are still on Synergy's regulated tariff and live in a contestable postcode, the cheapest alternative market offer is typically Alinta Energy's Fair Go 24 plan at 28.5c/kWh with a 98c daily charge — saving about $140/year on the same usage.
Perth gets 3,200+ sunshine hours a year, second only to Darwin among Australian capitals. A 6.6kW system generates about 10,000 kWh/year. The Distributed Energy Buyback Scheme (DEBS) pays 2.5-10c/kWh for exports depending on time of day (10c during peak 3pm-9pm, 2.5c off-peak). The real saving in Perth comes from self-consumption — running your pool pump, air conditioning, and appliances during daylight hours avoids the 30.8c/kWh retail rate. A solar household that self-consumes 60% of generation can cut their annual bill from $1,879 to under $800. The payback on a $5,500 system is about 5 years, faster than any eastern state capital.