Western Australia's gas supply is facing an "unusual situation" with three major outages amid a tricky period for the state's energy system.
These latest energy supply headaches come on top of fears for the stability of the state's largest power grid over a hot summer, with the system under pressure on multiple fronts.
So what's this latest challenge, and what does it mean for everyone hoping to keep the lights on and air conditioners running?
What's happened?
The latest problem started on Thursday, when an issue with the acid gas removal system at Chevron's Wheatstone project near Onslow forced it to stop production.
That meant a significant drop in the gas supplies available to customers along a natural gas pipeline stretching from Dampier in the Pilbara to Bunbury in the South-West, leaving it in what Energy Minister Bill Johnston described as an "unstable state".
To bring demand back in line with reduced supply, "urgent, immediate" responses were needed.
That included asking big industry consumers to cut back on their usage, with retailers Kleenheat and Alinta tapping into reserves to keep the gas flowing.
In the days since, Mr Johnston said "commercial people are all doing those commercial things to keep the system in balance".
"Some people have more gas than they need and they'll sell some of that gas to people who are not getting the gas from Wheatstone that they would ordinarily get," he told 6PR yesterday.
He said the Chevron plant did not supply any government customers, only serving industry.
How bad is it?
Normally issues like this aren't ideal, but are usually manageable.
This time is different though because it comes at the same time as two other major disruptions to supply, which have increased pressure on everyone involved in the system.
A gas leak in a pipeline that supplies the Varanus Island processing facility has taken about 15 per cent of production capacity out of the system, with issues at a separate facility at Devil Creek removing a similar amount.
Mr Johnston took an optimistic view of the situation though.
"It does show the robustness of Western Australia's energy system that we can have three major incidents in the gas supply system and still maintain sufficient supply for Western Australia's energy needs," he said on Sunday.
Liberal leader David Honey said that comment showed the minister was out of touch, given the effects of the combined outages.
"He doesn't have his finger on the pulse," Dr Honey said.
"What this really illustrates is that minister Bill Johnston is not on top of his portfolios, and the Premier should put someone in charge who can do the job properly."
What impact is the outage having?
One of the places feeling the biggest impact is Alcoa's Kwinana Alumina Refinery, which yesterday was forced to cut back production by about 30 per cent.
"At this stage, no timeline has been identified for restoring full production," a spokesperson said.
Both Alcoa's Kwinana and Pinjarra facilities have also resorted to using diesel generators since Friday as a temporary fuel source.
Dr Honey, who spent nearly two decades working for Alcoa, including running its refineries, said pulling back capacity was not a decision that would be taken lightly.
"The plants themselves are designed to run at full pace all the time, and when you have to shut parts of them down, bringing them back online can be very difficult," he said.
Rio Tinto said it was also working to conserve gas supplies.
"To help with the availability of gas for Western Australian households, we were able to transition a significant proportion of our gas-powered electricity supply to diesel sources to reduce demand," a spokesperson said.
Not everyone is affected though, with BP and BHP telling the ABC their operations had not been impacted.
Does that mean the power will go out?
Mr Johnston said he was "very confident" the state would not run out of gas because the vast majority of WA's onshore gas supplies are used by industries like fertiliser or explosives production, with only about 27 per cent used to generate power, and seven per cent provided to residential gas customers.
"It's not like just because you're short on gas then you have a problem with your electricity supply," he told 6PR yesterday.
The energy minister said if the government started to grow concerned about having enough gas to keep the lights on, there were "extensive powers" that could be used to set aside market rules and decide where the gas goes.
"We don't have to use our emergency powers, but if things were to go bad we do have those emergency powers that we could step in, and we would always preference electricity production over any other activity," Mr Johnston said.
So what's happening now?
It was initially hoped the Wheatstone plant would be up and running by Sunday, but that was later pushed out to today.
The latest update from Chevron is that it's expected to start producing some gas again today, before ramping up to full capacity by the end of the week at the earliest.
Beyond that, Varanus and Devil Creek aren't expected to pick up production until towards the end of the month.
Shadow treasurer Steve Thomas said the issues were a warning sign of what he expected to be a bumpy road as WA transitions away from coal-fired power plants by 2030.
He anticipates the government will struggle to provide base load power as coal is phased out.
"The lack of gas today is not a disaster in itself, but it is a symptom of an energy system which is being poorly planned and badly managed," he said on Sunday.
"As all of that base load disappears, it will be an issue for the government every time there's a disruption in gas supply.
"They won't have the base load, even with the gas supply, to have a secure and safe base load power for the state of Western Australia."
Dr Honey said the government needed to make sure new projects weren't being held up, particularly in the Perth basin.
The government's transition plans away from coal include a $3.5 billion spend on various renewable energy capacity over a decade, including fast-start lithium-ion batteries and deep storage, such as pumped hydro.
Mr Johnston had been due to go on annual leave over the weekend, but is expected to remain working through the latest issue.
Just how long Mr Johnston will be waiting for his holiday, and gas consumers waiting for certainty, will depend on whether Chevron can start bringing Wheatstone back online today as planned.
