The Australian Energy Market Operator (AEMO) has called on all participants in the energy market to work towards a “unified approach to power system security” as it releases the details of its review into the partial South Australian blackout last week.
AEMO’s report found that electricity supply was interrupted to significantly more homes than was necessary. During the blackout, it was discovered that the network operator had cut supply by as much as 300 Megawatts, when AEMO had directed reductions of just 100 Megawatts.
SA Power Networks, who had been responsible for carrying out load-shedding, as issued an apology to customers for the mistake. An estimated 60,000 customers additional lost power during the event for approximately 30 minutes. SA Power Networks laid blame for the mistake on a software glitch in automated load shedding software, which may have cut power to as many triple the number of households than intended.
We apologise for the issue last Wednesday when we implemented AEMO’s instruction to shed load. Read our statement. pic.twitter.com/E4ly8RoBkY
— SA Power Networks (@SAPowerNetworks) February 15, 2017
SA Power Networks had used an automated system to cut supply to customers, to meet the instruction from AEMO to do so. It quickly became clear to network controllers working on the ground that the amount of power being cut was significantly more than what was being reported by the system. AEMO detected that approximately 300 Megawatts of load had been taken offline, triple the instruction to cut to supply by 100 Megawatts.
AEMO defended the need for the blackouts, as it was the only option available to it to ensure security of the electricity network. Fingers have been pointed at various players attributing blame, including the Pelican Point gas generator which had a second generator unit sitting idle.
ENGIE, the operator of the Pelican Point power station, advised AEMO that gas was not available to run the second unit, and it was unlikely to get the unit running before the need to cut power to homes would occur.
“165 MW of Pelican Point capacity had been notified as unavailable. The operator advised AEMO of a start-up time which would not have enabled AEMO to meet the system security requirements under the National Electricity Rules.“ AEMO’s report stated.
“Load shedding then became the only available option for AEMO to restore system security.”
AEMO cited contributing factors, including a faster than anticipated drop-off in generation from wind, higher temperatures and constraints on the interconnector linkages to Victoria, preventing additional generation being imported from the neighbouring state.
At the time load-shedding occurred, almost all thermal generators in South Australia, apart from Pelican Point and Torrens power station, were operating.
In a finding that is likely to renew questions about the ability for wind generation to supply power at crucial times, at the time of the blackout wind generation was providing just 96 Megawatts, out of a potential 1,595 Megawatts of wind capacity installed in the state. This was approximately 100 Megawatts below what AEMO had forecast for the time of day.
In a statement accompanying the report, AEMO called on all participants and policymakers to work together to ensure a coordinated response to the transition underway is possible.
“The complexities and challenges of managing short-notice generation capacity reductions amid high temperatures and increasing electricity consumption are real. And they’re here,” AEMO Executive General Manager Stakeholders and Information, Mr Joe Adamo said.
“Energy transition needs co-ordinated planning and this is best achieved when we are all dealing with facts.
“The facts in this report outline that load shedding became the only remaining available option for AEMO to restore power system security. This action prevented the risk of damage to crucial infrastructure, which if impacted, could have had a prolonged, and potentially disastrous impact to energy consumers,” said Mr Adamo.
AEMO is continuing to investigate the incident and may issue a supplementary report if new information is uncovered.