Western Australia has announced plans to wean itself off coal entirely within seven years. 

The McGowan government says it will close the two remaining state-owned coal plants by 2029 and spend $3.8 billion on wind and storage capacity needed for the renewable transition.

The Australian Energy Market Operator has updated its assumptions to say WA's only privately owned coal-fired generator, the 440MW Bluewaters south of Perth, will retire by the same time.

But a lobby for WA's gas users says the gas system will not be able to replace all of the state's coal-fired generation capacity by 2030.

“We don't usually get involved in coal issues,” says Richard Harris, chair of DomGas Alliance, which represents big industrial users including Wesfarmers, Alcoa and Yara.

“But we've actually been talking to the government and saying; ‘Guys, don't get rid of the coal plant so quickly because you're going to put enormous strain on the gas market by doing that’.

“From a couple of points of view - gas supply and infrastructure supply - we just don't think there's enough gas available to come into the market to compensate for losing all that coal plant.”

Additionally, green power lobby Sustainable Energy Now argues that WA is running out of time to build the new wind farms, transmission lines and backup power needed to keep the lights on.

“There are no free lunches here, that's the big thing,” says Ian Porter from Sustainable Energy Now.

Mr Porter said the state will need to build more gas-fired generation capacity, though it has not made such an announcement yet. 

He said renewable energy will struggle to affordably meet all of the demand throughout the year.

“For this, batteries really don't cut it because they're short-duration,” he said.

“They're considered for four hours.

“I'm talking about 100 hours or something like that, several days … where there's insufficient sun or wind.

“So the backup generation must be in place.

“But what we would like to see is the generation goes in but they don't use it very often – only in those [renewable energy drought] times.”

The WA Government has acknowledged that gas will be “crucial”.

“The state government has recognised the need to expedite development of renewable energy generation and storage projects,” a spokesperson said.