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AEMO’s defence of “we didn’t know” underscores case for change

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The Australian Energy Market Operator insists it was completely unaware about the nature of the fault ride-through settings on wind farms in Australia, even though the issue had been addressed and resolved in Europe a decade ago.

In the third, and most detailed, report into South Australia’s state-wide blackout in September, AEMO says it did not know that wind farms built in Australia had limits on their “fault-ride through” settings, which govern whether a wind farm can continue operating with multiple network faults of the type that occurred when tornadoes tore down three major transmission lines.

powergrid

AEMO, it seems, did not even think to ask and has sought to blame the wind farm operators for not telling them. “We don’t know what to ask if we don’t know what they are not telling us,” chairman Tony Marxsen told the AFR.

But that appears a weak excuse in light of the interim report by chief scientist Alan Finkel on Friday, which noted that the issue around fault ride through mechanisms had been identified as a risk in Europe a decade ago by market operators, and then addressed and resolved. Discussions about this issue have been held in energy circles for years. But AEMO, it seems, didn’t bother to read the manual.

AEMO also defends its decision to take no preventative action in the face of increasingly stark warnings about that nature of the storm that was sweeping across South Australia. It had no stand-by back up in place and was running the interconnector at near capacity, meaning it had little room to move.

But it admits, amid unfortunate gobble-de-gook, that maybe it should change the way it approaches such decisions, and put in a “more rigorous process” to assess changes of forecasts.

“While analysis indicates such a reassessment would have been likely to confirm the earlier assessment, the failure to undertake a reassessment has highlighted a weakness in AEMO’s processes,” it says of its decision to ignore upgraded storm warnings.

Indeed, the 160-page report highlights numerous deficiencies in the way that the Australian electricity grid is run, and nearly all the recommendations made by AEMO have nothing to do with renewable energy at all, but look at adopting practices and technologies that are currently available and widely used overseas, but have been largely ignored in Australia.

It also points to a greater malaise about the management of the Australian electricity industry, over and above Finkel’s lament of the policy stagnation and confusion in his preliminary report released on Friday.

For years energy experts have been advocating rule changes and practices that would make the grid faster and more responsive and take advantage of the possibilities of new technologies. But with gob-smacking arrogance, the market authorities have kicked these proposals down the road, saying they are not urgent, or not needed.

The AEMO report – as did Finkel’s – highlights just how urgent these reforms and rule changes are. The grid, noted Finkel, is locked in the last century, overpriced and dumb. The transition is happening and it is happening rapidly. There is no going back. And market rules, policies and practices need rapid reform.

This blackout – even with the catastrophic weather events that ripped three transmission lines out of the ground – may have been avoided. But the response of the operators and rule makers and policy makers has been as it always has been; simply to try to shove more generation and more poles and wires into the market.

There are actually smarter, more efficient, more responsive and cheaper solutions. Marxsen, in a speech to CEDA in Melbourne on Monday, acknowledged this – but a man who just about remembers how the grid was 50 years ago, still seems convinced that new technologies are 20-30, or even 50 years away.

They are not, they are here now, as Ross Garnaut and others suggested during questions, and they demand a proper recognition in case Australia goes about building a whole bunch of expensive new infrastructure – as AEMO recommends – that may not be needed.

Interestingly, Marxsen drew a comparison to the nature of internal combustion engines on a car with the spinning turbines of a coal or gas station (they both spin at around 3,000RPM). But cars are changing too, and may soon make the ICE redundant. One fears that Marxsen might try to look for a fuel cap on an electric vehicle.

A typical example is brought up in the AEMO report. The load-shedding capabilities of the South Australian grid were not exploited because they were not capable of reacting fast enough. There was no significant reduction under the demand response measures either.

Available smart technologies could have achieved this, and – thankfully – are a subject of AEMO’s recommendations. It is quite likely that had these been in place, the separation from the interconnector could have been avoided.

Indeed, nearly all the recommendations made by AEMO relate to market practices and technologies – trying to introduce ways to get the grid to act smarter and quicker. Much of this will inevitably revolve around battery storage and other smart control systems.

In the meantime, wind energy will continue to be held up by many as the principal culprit of the event, even though AEMO has made it clear that the nature of wind energy – its variability and output in high wind events – was not an issue.

It was, it says, a technology neutral event. Previous outages were the fault of coal and  gas, and this time it was due to wind and was possibly entirely preventable, although Marxsen said it was impossible to predict what may have happened otherwise.

AEMO has said that because the fault ride through settings were set too low, some 465MW of wind generation was lost in the chaotic seconds that followed the failure of the first transmission line.

This in turn caused an overload on the inter-connector to Victoria, a disconnection and then a blackout. AEMO seems confident that the blackout could have been avoided without these settings, which have now largely been fixed.

Indeed, there is little mention of the problematic overshooting and undershooting of the gas plants and there is no mention or analysis of this and its impact on the grid.

The data displayed here confirms that there were “bubbles” in the output that were highlighted in the report – look at around 14 to 15 seconds. This confirms that gas units do over and under oscillate and back off power after a fault, and may have contributed.

aemo gas

But the issue is not analysed. Battery storage may well have smoothed out those bubbles, according to a report last week from Lloyds Register and RES.

The “black start” procedures were also found wanting. Engie’s Mintaro diesel generator’s emergency back-up tripped after just five seconds due to a fault, rendering it useless.

Origin Energy’s Quarantine gas-fired power station also failed, AEMO said, due to different switching procedures used by ElectraNet. Attempts to use Quarantine were eventually abandoned and the operator had to wait unto the Heywood Interconnector could be restored and provide power to restart the generators at AGL’s Torrens Island units.

Over at Port Lincoln, at the other end of the grid, Engie’s diesel generators did not do much better. They fired up after the blackout, and worked for just a few hours before two of them tripped and the other had to be taken off-line due to frequency issues.

Numerous attempts to get them to work failed. Power in the areas was not restored for nearly another two days before the transmission line could be fixed.

AEMO should be given credit for getting the grid back up and running in the time it did, given the failure of the gas and diesel plants at both ends of the grid.

But by that time, just about everything that could go wrong, had gone wrong.

AEMO not knowing about the fault ride through settings well known by other grid operators; it took no precautions in the impending storm; and was not aware that the black-start providers were not in a fit state to act. It did not have the technologies and the mechanisms for a smarter and quicker response that could have kept at least part of the grid going.

A full judgement on its role, and its culture, will not be able to be made until an outside group has completed its investigation. In the meantime, all we have is an investigation by AEMO into its own actions.

For some reason, AEMO still wants to investigate whether the blackout would have occurred if the coal-fired power station at Port Augusta had still been running. It is still obsessed with the amount of synchronous and non synchronous generation and inertia.

But maybe now, after this report and the Finkel review, the market operators, the rule makers, the regulators and the policy makers should stop looking for the petrol cap and look to the future, not the past, for the right answers.  

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  • Chris Fraser

    The gas plant voltages oscillated all around at the critical stage because they are spinning and don’t react well to sudden reductions in load. Part of the problem really.

    • Nick

      The power output of the gas plants was moving because the angle of the system was moving. They just had to catch up, and they did. There’s no smoking gun there.

      • Chris Fraser

        Do you mean moving phase angle ?

        • Nick

          Yeah. The loss of transmission and generation will cause the angle to move. The inertia of the machines means the electrical phase angle is different than the mechanical one, causing the angle and thus power to move as the system moves to the new steady state value. Not a big deal.

          • Chris Fraser

            If the electrical phase angle is set by circumstances outside of a spinning machine’s control, cannot the generator’s response be smoother if there was a buffering device or capacitor or battery between them ?

          • Nick

            In the case of a generator tripping, sure, if the capacitor or battery puts out the same amount of power in the same location. For a line trip, not really. Power, impedance and phase angle are all tied together, so changing one is going to change the others. In the steady state, power is constant. So when impedance changes (because of a line trip), angle is going to change. Batteries can’t directly manipulate angle, they can only change angle by changing power.

  • DevMac

    “AEMO still wants to investigate whether the blackout would have occurred if the coal-fired power station at Port Augusta had still been running”

    Gives a good insight into the cultural problems the AEMO has. Whether the coal plant was running or not is immaterial given that it closed because it was no longer profitable. It’s the wrong question to ask – and it’s one they wouldn’t need to ask if they’d done their job properly in asking thorough questions of the very companies creating the Market that they’re supposedly Operating.

    If something has been caused by either incompetence or wilful negligence, most of the time incompetence will be the correct answer. Continuing to investigate the effect Port Augusta’s coal plant would or wouldn’t have had is confirming wilful negligence.

    And in regards to blaming renewables, at least the wind farms did what they were programmed to do, whereas the gas and diesel backups seemed to have a 100% failure rate.

    Does anyone do Disaster Recovery Testing at these places? This Energy Security Frydenberg speaks of, where’s the regulation to actually ensure it? THAT would have actually made a difference.

    • Cooma Doug

      They do regular system black recovery annalysis and testing involving all players in a real time function. Each player gets to go through it as if its really on.

      • DevMac

        I figured they would, but the fact that two of them failed during a “live” contingency points to the testing not being where it needs to be.

        Often that comes down to dollars and risk vs reward though – business decisions as opposed to technical (in)competence.

    • Cooma Doug

      When you have a lot of fossil fuel gens the rate of change of frequency is slower than is the case with renewable plant. The problem was a rate of change factor of just 3000 mw seconds. This meaning if you lost 500 mws of generation or supply, the frequency would fall below sustainable levels and be below 48 htz far too soon for gas or diesel response.
      There was easily enough load shedding available but not the ability to initiate it in time.
      The solutions to this problem are available with new technology rapid load side response. It could have been done in this case with this rate of change if the load side options were in place.

      • DJR96

        “When you have a lot of fossil fuel gens the rate of change of frequency is slower than is the case with renewable plant.”

        Unfortunately all the existing renewable plant have to simply follow whatever the grid frequency is, regardless of RoCoF. The NEM currently relies entirely on the fossil-fuelled generators and their inertia to control frequency. For so long as this is the case it will continue to have issues and preclude renewables from being able to be part of a solution.

  • George Michaelson

    What I read says condensers can be made out of generators for low marginal cost compared to almost any other change right now. So, how about instead of blame-shifting, we just cost out making some inertia for the system inside SA, by a conversion?

  • john

    As i see it the problem is the people in charge at the AEMO have not actually looked into how the system they look after runs, they have just taken the pay and slapped each other on the back and think they are doing a wonderful job.
    This is not unusual in lots of areas in business today.
    Often the manager is hopeless at knowing how his organisation works.
    He is brilliant however at doing a presentation about the outcomes and always has the reason for any failure which points to others never him/her self.
    In this case they are going to look if some power station was still running rather like a look somewhere else not at me story to me.
    The inter state transmission lines failed the equipment was not in place to look after this and the need for a safe start was not in place it seems.

    • Rod

      They haven’t accepted the blame for what I feel is their biggest mistake in the event.
      That is not having some contingency during a one in 50 Year storm that was well forecast.

      • john

        True.
        However details when explained cause peoples eyes to glass over.
        The message is out there Renewable Energy are the cause of the problem.
        Yes i know, however that is where we are at.

        • Rod

          Because they are being bombarded with lies.
          One story on my news feed today about the latest AEMO report had the headlines “Renewable power a factor of SA blackout”
          Yet later in the article quoted:

          “AEMO chair Tony Marxsen said tornadoes and a severe storm caused the blackout – which brought down three major transmission lines within 87 seconds.”
          AAP (Murdoch) GRRRRR

          • john

            You know exactly as your last line said aap murdock.
            Such is life we are living in Post Truth how very true

  • disqus_gF5uXVTUbL

    Grid/s are unreliable fossil fuel generators, unreliable long runs of poles and wires and unreliable renewable energy without storage, all setting us up for poor service quality. We’re a long way from local targeted renewable energy with storage, where all these problems of load matching and slow starts could be history.

  • Ken Dyer

    “There is “no excuse” for any board of a utility in Australia not to know
    what’s coming, Tony Seba said(and quite some time ago), outlining a world with little centralised power generation, 100 per cent electric vehicles and minimal private car
    ownership.
    http://www.smh.com.au/business/energy/its-the-end-of-energy-and-transportation-as-we-know-it-tony-seba-20160519-goz5bm.html

  • taiyoo

    The AEMO report also has a recommendation for “AEMO to assess the risks of when wind speeds are forecast to exceed protection settings on wind turbines, which would lead to ‘over-speed cut-outs”. I haven’t seen anyone saying this was an issue that contributed to the system black.

    • DJR96

      Wind turbines don’t “over-speed cutout” unless they have a failure of their primary control system – blade pitch control. But this is so important for safe operation it has multiple redundancies and fail-safes. No amount of braking, mechanically or electrically, will stop a wind turbine from turning without first turning the blade pitch to zero. So much so that if it does fail they will rotate the whole unit 90 degrees to the wind direction if necessary.

      They will however scale back output linearly when wind speeds go over around 90kmh. Have to to reduce the risk of toppling the tower over.