Power bills for tens of thousands of households could be pushed higher after the Barnett Government said it would review tariff structures.
Treasurer Mike Nahan announced the review while handing down his first Budget, flagging it would also canvass ways of streamlining the "huge" number of different concessions.
Confirmation of the review, which Dr Nahan wanted to report by November to use its recommendations for next year's Budget, came amid a further blowout in electricity subsidies.
According to Budget papers, the amount paid by the State to offset the cost of providing electricity would rise an extra $167.7 million over the next four years to $2.48 billion.
BUDGET HITS FIRST HOMEBUYERS | REVIEW MAY INCREASE ELECTRICITY PRICES | OPPOSITION, CCI ATTACK BUDGET | DUMPING FEES SKYROCKET | $60m FOR COUNCIL MERGERS | HOUSEHOLDS TO BE SLUGGED | TOUGH LAWS LOST IN POLICE BUDGET | HIT FOR MOTORISTS, COMMUTERS | HEALTH GETS $447m TOP UP | PRIVATE SECTOR TO BUILD SCHOOLS | LITTLE JOY IN ARTS | FULL COVERAGE - WA BUDGET 2014
The tariff review is likely to recommend a rise in fixed, or "supply", costs, with Dr Nahan saying he wanted to see a "shift in the onus" away from usage charges.
Such a move could lump thousands of customers, particularly those with solar panels, with bigger power bills.
However, it could also cut bills for thousands of other homes by reducing the amount households were charged for every unit of electricity they used.
Under current arrangements, most of a householder's bill stems from the electricity they use.
Only a small amount is charged specifically to recover the big fixed costs of building and maintaining the network - principally the poles and wires that transport electrons to homes.
These supply charges fall far short of meeting the network's costs.
The balance is taken from revenue generated by electricity use.
With the rapid uptake of solar panels in Perth and the South West, where almost 140,000 households have the systems, experts claim the tariff model is "broken".
They say customers with solar panels use less energy from the grid, and therefore pay lower bills, but are among the biggest users of the grid because they "export" energy as well.
The effect was reduced revenue to traditional electricity providers, such as network operator Western Power, and the Government having to lift usage charges faster to plug the gap.
Dr Nahan acknowledged the review could lead to fundamental changes but appeared to play down the extent to which fixed charges could be lifted.
"The direction will be revolutionary, but the extent I don't think will be," he said.
Shadow energy minister Bill Johnston accused Dr Nahan of being deceitful with the public by failing to announce the review before last year's election.
Mr Johnston said he would not support changes to electricity tariffs that were "unfair" to low-income earners.