Western Australians face an average $205, or 14.5 per cent, hike in their home electricity bills over the next two years, the Australian Energy Market Commission has forecast in a new report.
That will be nearly three times the national average over the same period.
Prices in the southwest, in the most populous part of the state, are expected to rise from $1412 this financial year to $1617 in 2018-19, the 2016 Residential Electricity Price Trends report predicts.
NSW, Victoria and Queensland households are tipped to enjoy lower electricity prices over the period than WA, while those in South Australia, Tasmania, the ACT and Northern Territory are forecast to receive higher bills.
The closure of Victoria's Hazelwood coal-fired power station will add $78 a year to energy bills around the country, excluding WA.
South Australians will be hit the hardest, with household bills to rise by $150 a year.
AEMC chairman John Pierce says WA retail prices are set by the state government but remain less than the cost of supply because of subsidies, and bills would need to increase by 11 per cent to reflect the total cost of supply.
"No two households use energy in the same way. Knowing how much power you use and when will be the key tool in controlling electricity costs in the future," Mr Pierce said.
WA Labor leader Mark McGowan said the government could not be trusted, partly because it planned to move the regulation of prices from a current state-based authority to the Australian Energy Regulator.
"If (poles and wires utility) Western Power is sold and regulation is sent east, as the Liberal Party plans to do, expect bigger rises in power prices than currently," he said.
Energy Minister Mike Nahan said West Australians continued to pay some of Australia's lowest prices for electricity.
He pointed to the government's current Electricity Market Review, which involves the deregulation of prices to drive costs and inefficiencies out of the electricity sector and keep bills down.