The popularity of rooftop solar panels has been highlighted by figures showing the number of Synergy customers with installations has exploded to 130,000 in just five years.
Data provided by the State-owned utility has revealed that in March 2009 just one household with solar panels was registered to the Renewable Energy Buyback Scheme.
Under the scheme, Synergy pays customers the wholesale price for electricity their panels pump back into the network.
Since March 2009, the number of customers with photovoltaic systems has risen dramatically.
The increase was initially induced by generous incentives including the State Government's feed-in tariff, which started in August 2010, but was hastily axed a year later amid spiralling costs.
Even after the tariff was scrapped and the Federal Government wound down its solar rebate scheme, demand has continued, fuelled by cheaper solar systems and high power prices.
As of last month, when 1647 new applicants signed up for the REBS, the number of solar households on the South West grid officially topped 130,000 - or about 13 per cent of the utility's customer base.
The figures are confirmation of the runaway popularity of solar panels but also highlight the challenges facing traditional electricity generators and providers, most of which are government-controlled in WA.
In its mid-year review this week, the State Government laid bare the extent of the problem by noting that falling electricity demand and increasing household solar panel use was decimating Synergy's revenue.
The situation also increases pressure on Energy Minister Mike Nahan to reform the way electricity bills are structured, given solar panels could ultimately make the conventional electricity system unviable.
About 85 per cent of a typical household electricity bill stems from power usage. Solar systems cut into this, which disproportionately affects the bottom line of traditional providers.
The State's power chiefs are urging Dr Nahan to increase the fixed component of an average bill to address the problem in a move that would hit hundreds of thousands of customers.
Dr Nahan said the economic watchdog would soon begin a review of electricity tariffs but there were no plans to cut or reduce the rate at which REBS customers were paid.
Insisting he supported solar panels, Dr Nahan said the biggest problem Synergy faced was its long-term contracts, under which it had to buy more energy than it needed.
Shadow energy minister Bill Johnston conceded households without solar panels should not be subsidising those that had them. He cautioned against changes that would leave struggling families worse off.