The Australian Energy Market Operator has reprimanded wind farm operators in South Australia for not informing the regulator about the safety settings on their turbines, which led to blackouts in September.
While AEMO has been criticised about its role in the lead-up to the September 28 outage, chairman Tony Marxsen said the obligation was on wind farm owners to inform the regulator about the settings of their turbines and how they deal with adverse events.
“We are facing a bit of a challenge here in that we don’t know what to ask if we don’t know what they are not telling us,” Dr Marxsen said in an interview with The Australian Financial Review.
“They have an obligation under the rules to provide that information. We have reviewed all the information provided and found no information about this particular feature of the turbine controls.
“The rules are very clear. They state that the proponent for connection has to provide models that fully represent the behaviour of their equipment under conditions of grid disturbance. In this particular circumstance, the models that were produced did not. We will be looking at this further in the March 2017 report.”
AEMO’s latest report to be released on Monday has made 15 recommendations to deal with future events and to reduce the risk of “islanding” SA, which has cost business millions of dollars in lost revenue.
The AEMO report confirmed earlier reports that the state-wide blackout in SA was caused by wind farms reducing their output after storms knocked down three transmission towers in the state’s north.
Within the space of seven seconds, 456 megawatts of output from nine wind farms north of Adelaide was taken out of the grid, which cause a surge of power through the Heywood connector to Victoria. The state’s electricity grid essentially “tripped”, causing it to be cut off from the rest of the NEM to protect it from other states.
AEMO said the influx of wind and solar projects in SA, which now account for about 40 per cent of the state’s output, as well as the removal of the more reliable synchronous generation like coal and gas had put unprecedented strain on the NEM.
“The significance of the event and the intensity of review has brought to the fore a range of broader issues associated with the changing generation mix across the NEM,” it said.
“The generation mix now includes more non-synchronous and inverter-connected plant, which has different characteristics to conventional plant and uses active control systems to ride through disturbances.”
But in a startling admission, AEMO said it was not even aware the wind turbines, which it approved to provide power into the NEM, had the safety features that caused them to scale back generation capacity.
“AEMO was not aware that some wind farms may not be capable of riding through multiple successive faults on the network,” it said. “AEMO was not aware of the protective feature of these generating units that caused these power reductions and has taken action to ensure the limitations are known and appropriately managed.”
The 15 preliminary recommendations cover AEMO being better prepared before extreme weather events, a stronger system protection scheme to minimise regional separation from the grid, quicker restoration following a “black system” and limiting the time of a market suspension after an event.
Dr Marxsen will use his speech in Melbourne to say the regulator was not singling out renewables saying previous supply disruptions in SA in 1999, 2004 and 2005 were caused by coal and gas-fired power stations.
“September was a truly technology-neutral blackout,” he will say in his speech.
But critics of SA’s headlong dive into renewables will use the AEMO report to push for a more balanced approach to the future of the NEM, warning there could be more blackouts if coal and gas were phased out of the grid too quickly.
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