S.A. blackout underlines need for smarter, quicker grid, says AEMO

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Final report by AEMO into S.A. blackout underlines need for major system overhaul, with market operator saying new, faster technologies like battery storage, demand management, wind and solar need to be adopted. It says having coal generator would have made no difference.

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The Australian Energy Market Operator says its investigations into the dramatic “system black” event last September in South Australia underline the need to for an overhaul of the energy market, and to embrace new fast response technologies, rather than relying on old “synchronous” coal and gas plant.

The fourth and final report into the state-wide blackout – which has sparked a huge political fight over the future of wind and solar generation in Australia, and scare campaigns about the impacts of more coal plant closures – was released on Tuesday.


It sheds little new light on the events that had not already been reported in the three previous reports, but rather than calling for a halt in what many describe as the inevitable energy transition, it underlines the need to embrace it.

This will be surely be one of the major initiatives from the newly installed CEO Audrey Zibelman, who was most recently the head of New York state’s ambitious “Reform the Energy Vision” program and its target of reaching 50 per cent renewables by 2030.

Indeed Zibelman, in her first public comments since taking her new role on March 20, underlined the urgency of change, and talked of the need of a “flexible network” that can respond in “real time and truly real time.”

“That is going to need a different approach,” she said. “Australia is leading the world …. ” She said the focus would be on better data and working on the “demand” side of the load. But because of the rapid pace of technological change “we don’t have multiple years any more” to get systems right.

The AEMO report into the system black acknowledged that there is now a need to source additional security from new technologies – such as storage and demand response, along with large-scale solar, wind farms, and household solar and storage – rather than relying on traditional coal and gas plants.

“As the generation mix continues to change across the NEM, it is no longer appropriate to rely solely on synchronous generators to provide essential non-energy system services (such as voltage control, frequency control, inertia, and system strength),” the report says.

“Instead, additional means of procuring these services must be considered, from non-synchronous generators (where it is technically feasible), or from network or non-network services (such as demand response and synchronous condensers). “

One of the big lessons of the event and subsequent reports is the need for a grid that is “smarter” and responds quicker to unforeseen events, and also for AEMO to better understand the performance characteristics of the plant at its disposal.

While the NEM has successfully dispatched and co-optimised markets for energy and ancillary services for many years, the current mechanisms may not deliver the services required for the future as traditional providers of synchronous generation retire,” it says.

Instead, it will need to turn to new sources such as utility-scale solar PV, wind farms, batteries, “and importantly” distributed generation such as rooftop solar and battery storage installed “behind the meter” in customer premises.

AGL VPP _ One of the first solar systems as part of the Virtual Power Plant

This refers to the development not just of large-scale storage linked with wind and solar farms, but also to the development of “virtual power plants” of residential solar and battery storage, the likes of which are being tested by AGL, SA Power Networks and others.

“Like all technology development, there is a need to support early deployment to ensure potentially attractive solutions can be both technically and commercially deployed in the NEM.”

Because of this, AEMO is looking to work with ARENA for more “proof of concepts” projects, although it has also argued in its submission to the Finkel Review for greater power over minor rule changes to be able to accommodate new technologies.

Already, the South Australian and Victorian governments have taken the initiative by announcing two of the biggest battery storage tenders in the world, both of around 100MW, in coming weeks and months.

AEMO also wants to look at fast frequency response from batteries and other storage technologies, inverter connected generators (wind and solar farms), DC interconnectors, supercapacitors and “improved”traditional sources such as flyweels and synchronous condensors.

Most mainstream media – and particularly the ABC and Murdoch media – used the report to once again blame wind energy for the blackout, and pursued that line in a later press conference.

But AEMO chairman Tony Marxsen said it was not about wind or any other technologies. Blackouts had been caused by settings on coal plants more than a decade ago, by gas plants (including one big near miss on March 3, and by wind farms.”

All caused massive disruption. They had very little to do with type of generation. It is not about renewables,” he said.

Pressed on whether  having a coal generator in the system would have made a different, he said, no “there are too many variables” and pointed to past blackouts caused by the failure of the ageing Northern generator that is no longer in service.

AEMO’s hunger for “good data” is not just limited to new wind and solar farms and behind the meter solar and battery storage. It has admitted – although it doesn’t make much of the issue in this 260-page report – that some legacy coal and gas generators have no performance standards, and that it may not even know what their control settings are.

AEMO also didn’t know about the software settings on fault ride through mechanisms on wind farms. While the nature of wind farms (their variability) was not an issue and the wind turbines “successfully rode through grid disturbances”, it was the control settings that its says were found to have led to the system black.

Those settings have since been adjusted, and the problem fixed, and means such an event will not be repeated, as was highlighted when the state’s two biggest gas generators unexpectedly tripped in early February. Despite the immediate loss of 600MW of generation, the grid held stable.

But the report also highlights that the big gas generators were not able to react quickly enough to the dramatic events that followed the collapse of three main transmission lines, because they needed up to six seconds to respond to changes in system frequency. By that time, it was too late

“The rapid decline in system frequency following loss of the Heywood Interconnector did not allow time for more substantial governor response from these units, as it can take up to six seconds for these generating units to increase their active power output when they participate in the contingency FCAS market.”

The issue around governor responses has been highlighted by several new reports submitted to the Finkel Review. Battery storage can provide a response in milliseconds and some say that installations of sufficient size may have helped avert the disastrous events of last September.

The issue goes further than that, though. In its own submission to Finkel, AEMO admits that many of the legacy coal and gas generators have no performance standards, and it may not even know what their control settings are.

This is underlining a push for a fact-finding mission, in the form of updating generation plant requirements, and also a push for more controls and measures across a range of issues.

AEMO has released a total of 19 recommendations, including eight that are new. Three key recommendations, including the change of the ride-through settings on wind farms, have already been implemented.

AEMO is also reviewing its own response to weather forecasts, admitting that a weather update provided on September 28 did not trigger a reassessment of power system contingencies.

It admits this is a “weakness” although it insists it still would not have prompted any further precautionary action – such as reducing flows on the interconnector or calling for more local back-up.

This was also a weakness highlighted in the recent heat-wave in South Australia, when it failed to anticipate high temperatures that led to a surge in demand and a shortfall in supply, leading to yet more rolling blackouts, more political controversy, and the push by the state government to announce its own energy plan, including its own measures to ensure system security by ensuring new technologies such as storage were introduced, and its own back up generation installed.

Indeed, AGL – the owner of the state’s biggest gas generator and many wind farms – said that its wind assets performed as expected and to their “generator performance standards and their licensing requirements.”

But it also questioned the way that AEMO had set up the network on the day – when it chose not to ramp down the flow of the inter-connector or commission additional back-up within the state.

“For example, why was there full reliance on the inter-connector and wind?” AGL said, before noting recommendations that had since been made that are directed at ensuring system strength and stability in circumstances where the interconnect may trip or fail.

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