Australia’s mammoth coal plants failed while its wind and rooftop solar installations shone during a major January heat wave in Victoria state, according to a report last week by the Australian Energy Market Operator (AEMO).
The report “confirms observations made at the time that its efforts to keep the lights on in the face of a record heat wave were undermined by a series of failures and capacity reductions at all three of Victoria’s big brown coal generators,” RenewEconomy reports. “In contrast, AEMO notes, renewables performed better at the time of the major load-shedding at 11 AM on January 25 than had been anticipated when modelling for the anticipated hot summer was completed.”
“The contribution from coal generation was significantly less than expected and renewables was slightly more than expected,” based on 2018 modelling, the national utility manager concluded.
RenewEconomy says the standout from the January 24-25 power shortage was the poor performance of the country’s brown coal-fired power plants. Victoria had to cut back on power supplies by shedding load on both days, and South Australia only averted that outcome by calling on emergency reserves. It was the kind of lapse in reliability that grid operators around the world do their utmost to prevent, and take very seriously when it occurs.
“AEMO notes the unprecedented heat over the two states at the time, but it already had one hand tied behind its back because one [coal] unit at Loy Yang A and another unit at Yallourn were offline, taking away some 855 MW of capacity,” the publication states. “Another unit at Yallourn was lost on the morning of January 25, removing another 355 MW of capacity, Loy Yang B struggled in the heat and lost a further 85 MW of capacity, and eventually Loy Yang A lost a second unit—again to a tube leak—taking away another 370 MW of capacity.”
Combined with higher-than-anticipated electricity demand, those coal outages “cruelled hopes of avoiding any load-shedding, and while the ability to summon emergency reserves reduced the extent of load-shedding by half, more than 260 MW of load was lost.”
While the coal plants “performed substantially worse than expected”, and hydro and natural gas plants met their production targets, wind and solar far exceeded expectations.
“This is important,” notes RenewEconomy Editor Giles Parkinson. “Wind and solar are often criticized because they are variable, or intermittent. They don’t claim to be dispatchable—unless they are paired with storage of some sort—but they can claim to be predictable.”
And predictability “is what counts for the market operator,” he adds. “Its major difficulties come from those generators—particularly the aging coal generators—that claim to be dispatchable but often are not, particularly in the heat.”
Parkinson says AEMO, the Energy Security Board, and the Australian Energy Market Commission are looking at how the country’s electricity system can adapt as heat waves become more common and the coal plants continue to age. “The three institutions are also looking at how they can better use and manage distributed energy resources (DER), which include rooftop solar, battery storage, and demand management, noting the huge increase in capacity expected from state-based schemes such as in Victoria.”