As reported by ABC by Nick Harmsen
South Australia’s renewables-heavy power mix was a factor in the statewide blackout in September, a new report by the Australian Energy Market Operator (AEMO) has confirmed.
The report is the third in a series of investigations into the extraordinary loss of power during wild storms.
Previous reports confirmed a series of tornadoes severed high-voltage power lines, setting off a catastrophic chain of faults which resulted in the Heywood interconnector being cut off.
The interconnector failure left the state islanded from the national power grid and prompted a massive and rapid fluctuation of frequency, forcing all generators across South Australia to go offline.
Historically, the rate of frequency change following an interconnector failure has been managed successfully using load shedding, as demonstrated during a blackout earlier this month.
But the AEMO found in September, “the proportionally low amount of conventional generation dispatched in SA at the time of separation, and the subsequent low inertia, resulted in a higher [rate of change of frequency] than had been experienced during previous separation events”.
Prior to the statewide blackout, windfarms had been providing 883 megawatts (MW) of power, the interconnector was operating close to its limit and providing 613 MW, while traditional thermal generators were providing just 330 MW of electricity.
Some of the state’s biggest gas generators, including Pelican Point, were not operating.
The AEMO has subsequently ordered that two major gas-fired power stations remain online at all times in South Australia to keep the grid in a secure operating state.