Pas-de-deux: Two big coal units trip at same time in Victoria

Pas-de-deux: Two big coal units trip at same time in Victoria

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Two big coal units fail simultaneously in Victoria, taking total trips to 44 since start of summer, and 13 for brown coal generators since Christmas. Tesla battery hopped in again.

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If the federal Coalition wants to turn to Australia’s ageing coal plants for reliability, let’s hope they know where to find some decent back-up.

Earlier Thursday morning, two of the country’s biggest coal units – 530MW blocks at the Loy Yang A (number two) and the Loy Yang B (number 1) brown coal generators – tripped at the same time, robbing the grid of 1,065MW of capacity in an instant.

Oops ….
Oops again …

There is no indication yet of what caused the outage – although it seems that the Loy Yang B unit tripped, causing  power surge which took out the number two unit at Loy Yang A. There is talk that the Loy Yang B unit will be out for a month, so it is relatively serious.

At least they didn’t fail in the midst of a heatwave. As it turned out, demand was low (but growing as the population slowly awakened and switched stuff on).

However, the outage did cause prices to double in Victoria as traders profited from the sudden scarcity, with the same impact passed on to South Australia’s electricity market, and to a lesser extent in NSW.

These are the 43rd and 44th trip of a major coal-fired unit in the Australian grid since the start of summer, according to The Australia’s Institute Coal and Gas Watch. Seven have occurred in March alone.

And they were the 12th and 13th suffered since Christmas by big brown coal generators, making a mockery of the federal government’s focus on coal-fired generation as a guarantor of “reliability”.

Wind and solar are criticised by the country’s energy minister Josh Frydenberg as “intermittent” – but at least with the case of wind and solar their variability is predictable. The same cannot be said of the coal fleet, or even some gas units when the going gets really hot.

And for those with a vested interest in the future (vested, because everyone should have one – a future, that is), this is how the Tesla big battery, also known as the Hornsdale Power Reserve, responded.

It is not paid to respond to faults such as these, mostly because a “fast frequency response” market in Australia, which could take advantage of such batteries, does not yet exist.

But the Tesla big battery does hop in when the frequency dips below 49.8 Hertz (the point that triggers a “contingency” response), as it did on Thursday, injecting a relatively modest 21MW into what is known as the FCAS market to help arrest the fall in frequency.

That’s the red bit (Tesla discharging) at the same time as the black spike (wholesale prices) to the left of centre in the graph above, signalling when the units tripped.

Update: An AGL spokesman said in a later statement: “Unit 2 at Loy Yang A power station tripped and was offline this morning following a fault at Loy Yang B power station which caused a power spike. The unit has returned to service.”

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  1. Joe 3 years ago

    The Coaler’s tripping must have been the reason for my lights flickering this morning? Where is the Joshie rousting on unreliable, intermittent baseload Coaler power?

  2. Guy Stewart 3 years ago

    Good work staying on top of these. There is bound to be another round of renewables are unreliable bullshit peddled after the SA election. Which either way it goes.

    Regularly unavailable (solar at night) is much easier to plan for than random, or peak heat failures.

    It’s the difference between sharing a car with a partner, and a car that doesn’t start sometimes, like at the traffic lights after it has stalled.

  3. MaxG 3 years ago

    This should be tweeted to the feral clowns 🙂

  4. Rrobert Garnett 3 years ago

    The fault that occurred with Loy Yang B was not the power station it was the high voltage transmission equipment that connects it to the grid. The generating unit in question has operated for about 210,000 hours since commissioning in 1993 with around 96% availability. The average car engine is lucky to do 3000 hours before it is a total write off. Work it out. Two hundred thousand kilometers at an average speed of 60 k. The Loy Yang B units have some of the finest boilers and turbines in the world and will run for at least another 150,000 hours. They will continue to do this at their design efficiencies.

    If that makes these stations unreliable then please explain what technologies do better. Solar panels degrade over times and most manufacturers will only give you 20 to 25 years of life. The capacitors in the invertors that solar panels use will be lucky if they last fifteen years. Wind turbines are a particularly cheap and nasty piece of engineering and will be lucky to last ten years, with probably five percent of them catching fire and being totally destroyed.

    Find a lithium ion battery that will last as long as Loy Yang B at 100% capacity and with the load factor of Loy Yang B and I will donate $100 to the Greens party. One example only as I’m only a poor engineer.

    The issue with coal is not reliability or capacity factor, it is the carbon dioxide it produces. That’s the argument that matters. The reliability thing is bullshit. It simply isn’t true.

    If you don’t believe me do some of your own research on the internet. There is heaps of stuff on coal plant reliability. Back in the day Neuarath power station in Germany won the Guinness book of records award for the highest coal plant capacity factor at 93% LYB does 96%

    How long does your wanky I-Phone last and what landfill site does it end up in?

    • Barri Mundee 3 years ago

      Yes all good Rrobert but when these very large units trip,(located centrally unlike distributed renewables) for whatever reason, they remove large slabs of generation from the grid. They are reliable until they are not and they are a dying technology. But I will happily concede they are needed, for now.

      Shit canning renewables is favourite ploy of CC deniers but does not really cut it. Makes you appear desperate to make your point.

      • C. Paul Barreira 3 years ago

        On these points see the article by Tony Lang at

      • Rrobert Garnett 3 years ago

        How was it I was shit canning renewables? I think climate change is the most dangerous issue we face. Solar panels have got a finite life and it’s less than well designed coal plant. Does this mean that solar is bad of course not. I put 3.6 kW of solar on my house twelve years ago and I’m going to double it. I was simply pointing out the facts as they stand.

        Have a look at a few sites on fires in wind turbine: Yes I know it’s the right wing telegraph, but have a look at the Gardian if you are a lefty liberal like me.

        Does this mean we shouldn’t have wind turbines. Of course not. But don’t try to claim they are somehow highly reliable and without environmental problems, unless you think burning fiberglass and aluminum is perfectly healthy for the environment and for reliability.

        Just think about the danger of bush fires in Victoria if one of these caught fire and spread burning debri for ten or twenty kilometers in a high wind. The last big bush fire in Victoria killed over 170 people. Some of those were started by people and some by power lines. Add in thousands of wind turbines and the risk will go up higher. Of course it’s people in the country who enjoy these kind of risks as you don’t see to many wind turbines in the Melbourne or Sydney suburbs.

        Telling lies about the reliability of coal plant doesn’t add anything to the argument.

        The facts are coal plant built within the last 25 years is a very mature technology and with its high capital cost AND the impact on the system and consumers when they do fail they are designed to be highly reliable and to have long lives. Coal from the Latrobe Valley has powered Victoria since 1921 so it can’t have been all that unreliable.

        I’m not a climate change denier and I think coal has to go. What shits me is all of you lot who continue to use electricity mostly generated by the output from coal stations whilst talking crap about them. Have any of you gone off grid? Three people I know who work in the power industry have. I would go off grid too if I had natural gas. I cannot afford the solar and wind capacity needed to heat water and the house during winter. I do have a solar electrically boosted reverse cycle hot water service, but in the middle of winter there’s not so much sun so I have to stay connected to the grid.

        Am I desperate to make my point? No I’m not. I have retired from the industry. I’m just fed up with nongs talking rubbish about things they know nothing about.

        In fact it is my opinion that thanks to all of you who voted to get rid of Gillard and who put Abbot in her place, the man who got rid of the Great Big Tax, we have lost any decent opportunity to do anything about climate change in Australia. I voted for Labour by the way. Sorry about that!

        I suppose the only little bit of light I can see at the end of the climate change tunnel is that most of you lot live in the big coastal cities and will be drown as the sea level rises four or five meters.

        I live 135 meters above sea level so I’ll probably burn to death or die of dehydration.

        Anyway we can all talk about it when we’re all down below.

        Apparently it’s pretty hot down there to. Of course Tony will be sitting up there on cloud nine telling God how good he is so don’t expect to be able to pay out on him unless God gets sick of listening to the dick-head which I suspect he will.

        • Barri Mundee 3 years ago

          So much emotive rubbish I don’t know where to start, so I won’t.

          Do not pretend you are anything but a more subtle climate change denier.

          I voted and vote for Labor (you can’t even spell the party’s name correctly).

    • neroden 3 years ago

      Donate your $100 now. You’ve already lost.

      • Rrobert Garnett 3 years ago

        On what evidence should I complete this transaction? My credit card is in my hand just itching to be debited.

  5. Les Johnston 3 years ago

    Probability analysis was (should have been) taught in high school maths. Risk is supposed to be the driver behind electricity supply. Large plant failures do happen, very small distributed supplies provide a much more reliable system even if each small supply unit has a very high probability of failure. Whether the small units burn hydrocarbons or not is not relevant under risk analysis for electrical supply.

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