Western Australia's power network was unable to meet demand over the ferociously hot Christmas period last year, leading to outages that affected more than 100,000 people, an independent review has found.
The blackouts came amid record-breaking temperatures, including the hottest Christmas Day on record, and four consecutive days over 40 degrees Celsius.
The review, which was tabled in WA Parliament today, was carried out by the Australian Energy Market Commissioner Michelle Shepherd.
She found about 26,000 customers were without power for more than 12 hours, and 40,000 were left without power more than once.
"The review concluded the main cause for the outages was parts of the distribution network did not have the technical capacity to deliver electricity to meet the unprecedented demand experienced at the time," Ms Shepherd wrote.
"In addition, many of the outages were significantly extended due to the fire weather conditions, restricting Western Power's ability to safely restore power until conditions eased.
"While the extreme heatwave which led to the outages is historically rare, the Bureau of Meteorology advised similar conditions are likely to occur more frequently in the future due to the impacts of climate change."
Equipment overload caused blackouts
The inquiry identified the outages were not because of insufficient generation or higher than usual asset failures, but because of equipment overloads.
"Customer demand from the grid, particularly in residential areas, was at very high levels during the Christmas 2021 [period], driven by persistent high temperatures over the long weekend holiday period," the report reads.
However, steps Western Power took to reduce the risk of fire were found to have contributed to more outages that lasted longer.
The utility was also limited in what it could do to spread load across the network because of higher demand.
"A few backup generators were also deployed but had a small impact," the report noted.
"Another cause of repeat outages impacting a small number of customers included fault switching, where a part of the network is turned off to enable another part to be turned on.
"These outages are generally of a shorter duration."
Western Power prepares for future outages
Energy minister Bill Johnston said he had asked Western Power for a timeline of when the report's six recommendations would be implemented.
"The recommendations of the report include improving Western Power's planning and forecasting, approach to fire risk management and operational response to extreme events," he told parliament.
"It also recommended improvements to customer and community communications, and greater transparency of reliability issues."
He said Western Power was already preparing for future outages by rolling out batteries, micro grids, standalone power systems and other network improvements.
The report also recommended the state government-owned corporation improve its forecasting to account for the "rapidly changing way electricity is produced and consumed by customers", including the use of rooftop solar, and appoint an independent expert to identify the best way of balancing fire risk with the need to restore power.
