Critical problems in the integrated power grid

Recycling a comment from RobK in a previous thread on the renewable road to ruin. He reports a talk by an electrical engineer, Kate Summers of Pacific Hydro. She has excessive enthusiasm for renewable energy, especially hydro (which is cheating), but the most important take-home that I can understand is the massive spinning turbines are under huge mechanical stresses due to fluctuating voltage that is not being controlled properly in the integrated system. This will increase downtime and unscheduled outages and shorten their working lives.

Comments and further explanation are invited from qualified Cats, I took several pages of notes but will not take the time to listen again or attempt to improve on RobK and any others who are prepared to help.

Part of the problem that will appeal to students of catallaxies is her claim that the centralised control and monitoring in the integrated system fails compared with the decentralised controls in stand-alone systems.

Another vital take-home from the first or second question was the observation that among the 33 senior managers of the four regulatory agencies there are 3 with science or engineering qualifications.

Kate Summers “Power system control or market control of a power system: Is there a fundamental loss of power system control?”

On Wednesday 15th August 2018 I was happy to speak at University of Melbourne’s Climate and Energy College about a topic that I see as a very important one to the ongoing stability of the electricity grid (and hence to the continuation of the energy transition).

As I note during my presentation, it seems to me that we have moved from centralised planning but distributed control, to a market with decentralised planning but centralised control. This is apparent, for instance, in market provisions for ancillary services. I am not sure that we all understand the implications of this.

This is the commentary by RobK.

An interesting 60min presentation looking at an aspect of FCAS dealing with hunting of frequency control partially caused by poor integration of digital and rotory manchine control. Some interesting comments on the lack of engineering input to system design.

Presented by a power engineer with RE background. There are many other issues than mentioned here but interesting insights into the systems workings.

It seems worse than I expected.

At 6am Wind and Other were delivering 13% of the 20GW demand.

This entry was posted in Global warming and climate change policy, Rafe. Bookmark the permalink.

42 Responses to Critical problems in the integrated power grid

  1. Mark M

    The stupid. It hurts …

    PM rejects calls to abandon Paris targets
    18 sept 2018
    https://www.sbs.com.au/news/pm-rejects-calls-to-abandon-paris-targets

    “The prime minister has vowed not to bow to conservative pressure to abandon the Paris agreement, saying it would have no impact on electricity prices.”

    The Paris targets will have no impacts on droughts, either. Idiot.

  2. v_maet

    Another interesting read can be found here:
    http://www.wattclarity.com.au/articles/2018/09/further-analysis-of-the-very-rare-double-islanding-events-of-saturday-25th-august-2018/

    Interconnectors between SA-Vic and QLD-NSW triped at the same time.
    SA power prices skyrocketed and the Hornsdale Power Reserve (Tesla Battery) wasn’t able to help because it was low on charge……………..

    Meanwhile QLD prices stayed low because there was suddenly an oversupply of cheap reliable coal power.

  3. Rafe Champion

    We really need a running commentary on the glitches in the system, I think somewhere there is a list of faults that are being fixed in the system at any given moment, mostly minor but there is next to nothing said in public even about the major ones. Congratulations to the MSM.

  4. yarpos

    “Another vital take-home from the first or second question was the observation that among the 33 senior managers of the four regulatory agencies there are 3 with science or engineering qualifications.”

    A key point. The silence of the science and engineering communities and their professional bodies does them no credit. I guess when funding and careers are at stake its a big ask.

  5. Boambee John

    Yarpos

    . I guess when funding and careers are at stake its a big ask.

    Three out of 33 suggests that the careers are already gone.

    Time for the Samson option. Bring the whole edifice down.

  6. Herodotus

    The destruction of our power system is the greatest existential threat since WW2.

  7. H B Bear

    Time for the Samson option. Bring the whole edifice down.

    As soon as the Pony Club can no longer export 1,000 MW of coal power south all day the NEM is finished. I’d say within two years. You can add as many windmills as you like, it isn’t going to make any difference.

  8. The destruction of our power system is the greatest existential threat since WW2.

    Yes.

    I fear it is too late. The lead time for adding serious generation capacity, 5-10 years, is longer than an electoral cycle.

    The seeds of destruction will produce a healthy crop of disasters.

  9. Ben

    Rafe, I have been following Kate Summers’ work on this topic, she has presented a couple of times in various places. Perhaps I can paraphrase the problem Kate has identified in simpler terms:

    Cause
    Synchronous generator (steam, gas, hydro) governors have been detuned (the National Electricity Rule deadbands) so that they do not control frequency as tightly as they can do.

    Effect
    Increasing number of frequency transients resulting in increased call on FCAS services, therefore increased cost and risk.

  10. RobK

    Ben,
    Synchronous generator (steam, gas, hydro) governors have been detuned (the National Electricity Rule deadbands) so that they do not control frequency as tightly as they can do.
    This goes in hand with extra “ride through” settings on wind farms so they dont drop-off so quickly when frequency excursions occur. This was a result of report into the SA blackout due to the storm front. This fixes one problem but potentially exacerbates others.

  11. Roger

    “The prime minister has vowed not to bow to conservative pressure to abandon the Paris agreement, saying it would have no impact on electricity prices.”

    He will come to regret this too.

  12. Tator

    And all this renewable push even though by 2020, China’s emissions alone will exceed the rest of the developed world
    See Chart 4
    so basically Australia is being shafted by the leftard Greenfilth for being successful.
    May they all suffer the fate of the Sirius Cybernetic Corp Public Relations branch and be the first up against the wall when the revolution comes.

  13. Dr Fred Lenin

    Like all socialist brain fart ideas the soros/u.n.communist plot to destroy the dangers of peoples objections to their plot ,the destruction of reliable energy scam has never been thought through properly . I spent years examining great development and building plans as devils advocate ,I saved a lot of money and careers simply by thoroughly investigating every aspect of a plan ,the pros and cons were written on two separate shrikes then submitted to the people who were risking the capital so they could make a thoroughly informed decision and revision of plans . Politicians being from the lawtrade or union mafia gangs don’t have to do this ,they are just soooo smart and it’s mot their money anyway . The scheme was doomed before they finished thinking about it .

  14. duncanm

    yarpos
    #2818939, posted on September 18, 2018 at 8:29 am

    A key point. The silence of the science and engineering communities and their professional bodies does them no credit.

    I suspect it is the usual case of the professional bodies being run by the people who talk, but don’t walk. See AMA, etc.

  15. Dr Faustus

    Ben: Those are certainly the mechanical causes/effects.

    However I think the important point Kate Summers makes here is that the FCAS ‘market’ is being gamed by the new owners of what was once State-owned synchronous generators – particularly in the contingency market, when a generator/interconnector/load drops off.

    The two charts she shows from around 19:00 to 21:00 tell the story.

    It’s the unintended consequence one might expect from a ‘market’ created by experts out of policy.

  16. Kneel

    “… the FCAS ‘market’ is being gamed by the new owners of what was once State-owned synchronous generators…”

    What do you suggest they do – “lie back and think of Britain” or something?
    The synchronous generators have been screwed mightily by legislation favouring the ruinables crowd, it’s only fair that they get a chance to game the system too – after all, they didn’t make the rules, they’re just trying to survive.

  17. RobK

    Dr Faustus,
    You may be right about the gaming to an extent, but the issue is real enough to warrent action. I was surprised hunting of frequency was proving somewhat intractable but the variation of supply from RE is emense. The SA storm front was reported as striking all the wind farms more or less simultaneously(hardly a surprise given the topography) , causing first maximum output of wind power, then, the sudden drop-off on over frequency of some, which caused the link and other wind to drop off on under frequency as they couldn’t hold the load. Sudden load or supply changes are a nightmare in these high energy machines.
    In essence, FCAS, to me, means the grid is not ready for high penetration RE. There are work-arounds, the best of which are very expensive. We’ve been seeing a cheap nasty version of wobbly RE at subsidized establishment cost. It will be dearer in the longer term in my view.

  18. jock

    Although i am not an electical engineer with base load generation experience, Ben above is on the money. The system needs balance and this can only be provided by base load power. The more renewable/ interruptable power that is introduced the less stable the system.

  19. billie

    Yes Jock, that may be so, but you haven’t considered feelings, have you?

    To wit, when one wants ever so much for the world to run on renewables, well then, it must do so and anything uttered by a naysayer (yourself) is merely denial of the obvious, and to be ignored.

    If (!) you have the temerity to pursue this dreadful line of thought, then a name will be cast upon you and that name shall be attacked!

    Thus spoke the harpy (or swampy, your call)

    Balance is when I am happy, and my friends are happy, not when some stupid machine or mechanism is .. in balance, what a world that would be!

  20. Craig Mc

    Ben & Faustus are both on the money. Add to that what I suspect is a gas-peaking oligopoly in which all “competitors” refrain from entering the market until prices are giddy from the height.

    Who knew a system designed by merchant bankers would benefit merchant bankers at consumers’ expense?

    Past government responses to perceived dodgy markets was to enter them as a player and set price ceilings. Maybe instead of building a new base load plant, the government should build its own GP plants. I’m sure even a public enterprise can make money at $5,000/MWh.

  21. John Smith101

    Not sure how correct this explanation is but this is my understanding of the situation.

    Base-load generation is very important. It is required to maintain the stability of the system – unreliable and fluctuating wind generation cannot do this. Stability of the system means maintaining a frequency, in this case, of 500 cycles per sec, or 50 hertz (50Hz). This is known as a frequency control auxiliary service (FCAS). Very minor fluctuations, say a small fraction of a hertz, may be okay for resistive circuitry (electric motors, etc) but more than that will damage, most likely permanently, semi-conductor-based protective circuitry like smart-fridges, computers, etcetera.

    The problem is that asynchronous wind generation cannot maintain this steady frequency, resulting in mismatches between electricity supply and demand, which can result in rapid loss of load. Rapid loss of load means that protective circuitry systems within the grid activate, so as to not cause permanent damage to downstream protective circuitry, such as home computers, and other electronics. This is normally done by self-disconnection, interrupting all the load they are supporting – in other words, a blackout. Frequency load shedding such as this can result in a cascading effect, as the load is shed to the next protective part of the system. This leads to widespread blackouts, as had been experienced in those places connected to the electricity grid, following the removal of their base-load generator.

    Base load generators, such as coal-fired power stations, overcome frequency fluctuations through the use of inertia. Attached to the generators are enormous and heavy spinning flywheels, which keep on spinning after reductions in or loss of power, thereby maintaining system frequency stability, as long as the momentum of the flywheel keeps turning. Other types of electricity generation utilise different techniques to maintain system stability.

    Jo Nova posted an article on this subject on 7 December 2017: Another hidden cost of intermittent renewables (It’s time to talk about FCAS and roaring price spikes!).

    From the article:

    Nobody says much about FCAS in public – but it’s become a hot topic among Australia’s energy-nerds and electricity traders. It never used to be a big deal, because we got it at very low cost from huge turbines — from coal, hydro, and gas. Suddenly, it is costing a lot more. As I discovered below, in one month FCAS charges in South Australia rose from $25,000 to $26 million. Wow, just wow.
    What is FCAS?
    FCAS means “Frequency Control Ancillary Service”. With an AC (or alternating current) system, frequency is everything – the rapid push-pull rhythm that is the power. FCAS is a way of keeping the beat close to the heavenly 50Hz hum (or 60Hz in America and Korea). Network managers cry when things stray outside 49.85Hz or 50.15Hz. So controlling the frequency is a very necessary “other service” supplied by traditional generators, but not so much from intermittent renewables. Large spinning turbines “do” FCAS without a lot of effort. And the cost used to be a tiny fraction of the total electricity bill, but it is rapidly rising in Australia, thanks to the effect of the RET (Renewable Energy Target).

  22. RobK

    Frequency Control is important because it is inter-related with voltage and current. It needs to be constant because it influences magnetic flux of inductors and chargabilty of capacitors(and the speed at which motors turn). Consequently, it is not just the frequency that is watched but the “rate of change of frequency “(RoCoF). A rapid change of frequency has a far bigger detrimental effect than the same change over a few seconds, not just because the reponse is easier but the effects on voltage and current spikes is less. Big inertia machines absorb and reprocess spikes of energy. Inverters follow whatever is on the line. Synthetic inertia has some trouble picking a spike of noise from a frequency excursion. The upshot is synchronous machines tend to condition the energy to clean, noise free electricity. This means that voltage and current remain as useful measures of load and fault detection. A high proportion of non synchronous supply makes for dirty electricity that is difficult to control amidst the noise.

  23. NuThink

    A series of 4 short videos demonstrating in a laboratory setup the problems of synchronising AC generators, and showing the 3 lights synchronization method. Even on a small desktop setup he will not engage them out of sync because of the damage that will occur, so imagine what a grid sized generator will do when out of sync. Massive currents and damage.
    Also demonstrates how a generator becomes a motor when out of sync, so it takes energy out of the system and slips in phase slightly.
    He must engage the connection when all lights are off (in phase and the frequency is very close to each other else there will be a very big jolt to the system.)

    https://www.youtube.com/watch?v=RGPCIypib5Q part 1
    https://www.youtube.com/watch?v=sFohkp2aaU4 part 2
    https://www.youtube.com/watch?v=GRk_qJxaxh8 part 3
    https://www.youtube.com/watch?v=RT1ySBc-Bls part 4

  24. Tezza

    Thanks for the post, Rafe.

    Comments from RobK, John Smith 101 and Ben are on the money as far as my readings can tell.

    According to Graham Palmer’s book Energy in Australia, every alternating current grid in the world depends for its stability on some 90%+ of its electricity being generated by ‘synchronous rotating machinery’, whatever the fuel source (hydro, nuclear, gas, oil, biomass or coal). There is massive inertia from the weight of the rotating generators and turbines, and each unit is phase-locked to the grid at a rotational speed depending on the design of the generator. At that controlled speed, each unit contributes synchronously to a stable 50 Hz cycle of AC distributed through the grid.
    As the load on the grid increases (for example at the instant people get home from work and turn on heaters, ovens etc), the grid frequency ‘droops’ slightly from the increased load, but the droop is resisted by the inertia of the system. The slight droop is the signal for more fuel to be used by each generator to increase grid supplies and maintain frequency stability.

    This is close to magic, and is the result of the world’s electric grids having evolved over about 140 years. We enjoyed that ’emergent order’. We got frequency control ancillary services virtually for free from despatchable power. The Green Left have replaced an emergent order that they never understood with a centrally controlled system (which they still don’t understand).

    Now we have to pay for FCAS, as wind and solar are asynchronous.

    FCAS with diminishing despatchable power from synchronous rotating machinery requires additional investment in such things as synchronous condensers. AGL is reportedly considering re-purposing Liddell’s generators as synchronous condensers. As I understand it, this would in effect use electricity to spin the generators and turbines to continue their contribution of inertia to the stability of the grid – a FCAS that AGL would charge us for. Like Snowy 2.0, they would leave the system with less electricity for consumers.
    Mind boggling, hey?

  25. .

    So are renewables generators even required to supply the system with properly inverted AC electricity?

  26. Bushkid

    Herodotus
    #2818957, posted on September 18, 2018 at 9:00 am
    The destruction of our power system is the greatest existential threat since WW2.

    Along with our abysmally – some would say dangerously and even criminally – low in-country petroleum reserves.

    What is it about lack of “reserves” in any sense that these idiots don’t understand? And why?

  27. No scientific expertise on this board also. No wonder they prevented the public from viewing the remains of Vikings on grounds of myth and superstition.

    https://museumsvictoria.com.au/about-us/board-and-executive-team/

  28. .

    Like Snowy 2.0, they would leave the system with less electricity for consumers.

    Really? It is about price arbitrage.

    The problem with solar and wind is we get inconsistent hourly and daily baseload output, and it cannot deliver peak or should electricity at all, or with any reliability.

  29. Bushkid

    Roger
    #2818986, posted on September 18, 2018 at 9:44 am
    “The prime minister has vowed not to bow to conservative pressure to abandon the Paris agreement, saying it would have no impact on electricity prices.”

    He will come to regret this too.

    Indeed, our newly-minted shiny and sparkly new PM just doesn’t seem to understand that the continuing unpopularity of Turnbull was mostly due to his single minded (and bloody-minded) pursuit of all things CAGW, UN, “carbon tax”, and “green”.

    Initial anger was at the manner and lack of reasonable excuse for knifing Abbott, but Turnbull’s performance, arrogance and adherence to the UN agenda for ever after long ago overcame even that anger. For Morrison to so blindly follow in his footsteps doesn’t change anything, except to lower the arrogance quotient a little.

  30. RobK

    Tezza, that’s correct. Synchronous condensors are essentially a synchronous electric motor where the armature exciter is controlled to bring the Power Factor (reactive power) back into specifiication. It also helps reduce other noise and improves transmission efficiency by increasing the portion of active power transmitted.
    Dot, yes inverters supply AC on line frequency and generally at unity power factor, i.e. the voltage and current are in phase with each other. There are often little spikes and harmonics too. Unity P.F. would be ok if everything was steady, but local loads especially motors shift the angle between voltage and current. The grid compensates for this at certain points. The problem with RE is it comes and goes randomly, in the case of wind and big solar, it comes from the supply side, in the case of domestic PV it comes from the consumer side. These changes in P.F. cause the loads and the transmission lines to further change the character of the supply in the grid, making monitoring and control that much harder. When a cloud momentarily covers the sun in a suburban street, the grid sees a sudden load dropped on it and tries to compensate. The cloud passes, the load disappears. The control systems work overtime chasing shadows, system noise is then generated by the loads as well, the instability perpetuates. Finkel recommended rotory (synchronous) condensors be installed. These are expensive to buy and run. I beleive in parts of Canada they are mandatory for commercial RE. Hidden costs of RE.

  31. gowest

    Nothing will change at govt level whilst people like the doctor’s wives in Wentworth can get cheap, subsidised, solar power that the rest of us pay for. The obvious solution is to turn off their solar panels.
    Turn off the switch. Cheer when they bitch about the power cost!
    A “keep the power costs down” game with drones and paint to educate and entertain our bored youth.
    As for wind farms – a camera feed showing all the birds getting the chop….

  32. old bloke

    Tezza
    #2819264, posted on September 18, 2018 at 5:12 pm

    According to Graham Palmer’s book Energy in Australia, every alternating current grid in the world depends for its stability on some 90%+ of its electricity being generated by ‘synchronous rotating machinery’, whatever the fuel source (hydro, nuclear, gas, oil, biomass or coal).

    You can add diesel fuel to that list of sources. Contracts for renewable energy should be written with the supplier guaranteeing nameplate current at a constant 50 Hz. The contractors would then be required to install a DRUPS unit (Diesel rotary uninterruptible power supply) for every wind generator, or a bank of DRUPS units at an aggregate point somewhere prior to connection to the grid.

    The DRUPS units act as an alternator on the wind turbine output through a flywheel mechanism (to maintain a constant 50 Hz), then as a generator in the event of windmill shutdown or low output.

  33. Rohan

    arpos
    #2818939, posted on September 18, 2018 at 8:29 am
    The silence of the science and engineering communities and their professional bodies does them no credit. I guess when funding and careers are at stake its a big ask.

    IEAust has drunk the greenfilth ruinables coolaid. The march through all institutions is pretty much complete.

  34. Bushkid;

    Along with our abysmally – some would say dangerously and even criminally – low in-country petroleum reserves.

    A quick short term solution to this potentially catastrophic issue would be to build several very large fuel stores. An even quicker short term solution would be to require all servos to maintain 90% stocks in their storage, which a quick question to a mate in the industry says are mostly only 50% utilised. Extra costs imposed to be subsidised by dealers/industry until the storage/production problem is solved.

  35. Tel

    As for wind farms – a camera feed showing all the birds getting the chop….

    Showing that feed would be a quick trip to YouTube oblivion.

    Because you know their community standards and all that. What part of their standards exactly? Oh, we can’t say, just somehow someone was offended somewhere.

    Community standards = communist standards.

  36. Rohan

    jock
    #2819117, posted on September 18, 2018 at 12:43 pm
    The more renewable/ interruptable power that is introduced the less stable the system.

    While I’m a chemical engineer I do have experience in control systems. You dont increase control stability by increasing the amount of input fluctuations to that system. Its directly analagous to the suspension on a car. If you run over a heavily corrigated road at slow speed, the suspension has time to adequately adjust to the frequency of change between the peaks and troughs of the road. You therefore have complete steering control of the car. Increase that speed and eventually the suspension cannot cope with the high frequency of impact. You’ll loose control and plough into a tree at the next sweeping bend irrespective of how hard you turn the wheel.

    The grid is not far off hitting that tree and I think that sweeping bend will occur sometime this summer.

  37. billie

    Rohan
    “You’ll loose control and plough into a tree at the next sweeping bend irrespective of how hard you turn the wheel.”

    Maybe we have to lose control so that someone else gets a turn at the wheel … after we fix the car of course, since it’s wrapped around a tree at the moment. This is not going to be an easy fix methinks.

    Indeed, this summer will be interesting and I look forward to seeing a new form of dodging of responsibility and accountability, it will be like the olympic diving competitions, degrees of difficulty with pike.

    Current records held by the previous SA Labor government, much like the current SA Liberal government in fact.

    The more things change ..

  38. Mundi

    If you want to know how scary things are getting consider this:

    In QLD engineers are required to be registered and in most states CP Eng is a defacto standard.

    As part of having that qualification you have to agree to abide by ethics policies.

    In the ethics policy it requires engineers to use “sustainable” outcomes, and they are not allowed to “compromise the ability of future life to enjoy the same or better environment as currently enjoyed”

    This is starting to be actually enforced to the point where if you work on a project that isn’t carbon neutral, you risk being stripped as a practicing engineer.

    This is already happened to engineers working on the coal plants that NSW sold. Luckily in NSW there is no regulation requiring registration so they just tell EA to go jump. But in QLD engineers are getting into a tough spot. Victoristan is following QLD and regulating engineers.

  39. Ben

    There are other points to consider in this discussion:
    – adjusting the frequency control deadbands in a control system takes only a matter of minutes for the on-site control system engineer – once the rules are updated…
    – adjusting the deadbands to force the synchronous governors to react earlier to frequency error will tighten up the grid frequency and reduce the reliance on the FCAS market
    – it is also true that there is no compensation for synchronous generators to provide this inherent frequency control, but there is compensation for a generator being directed to follow an AEMO remote MW set point

    So the technical side is not so much about renewables vs frequency, it is more about making the synchronous generators do the job they are designed and fully capable of doing… with a side note about why on earth the regulator has replaced basic engineering principles with ineffective market principles.

  40. Myrddin Seren

    Mundi

    If you want to know how scary things are getting consider this:

    …. if you work on a project that isn’t carbon neutral, you risk being stripped as a practicing engineer.

    This is already happened to engineers working on the coal plants that NSW sold.

    Wow – just wow !

    So the Left, having Borged Engineers Australia, are now ensuring there is no skill set to engineer and operate new coal-fired plants even if a government bit-the-bullet and tried to build one ?!

    That is a terrifying precedent – ‘Citizen Specialist – your skill set has now been deemed as a Thought Crime. Cease practicing, leave the country or join with us in a return of industrial society to the glorious year that was 1815 !’

  41. Myrrdin:

    That is a terrifying precedent – ‘Citizen Specialist – your skill set has now been deemed as a Thought Crime.

    That kind of legislation/regulation has been creeping into Professional Regulatory bodies for about five years. Remember when the Nurses Registration Board in Qld (or whatever they call themselves now) wanted each midwife to make an announcement about white privilege when they first met a patient?

  42. .

    Remember when the Nurses Registration Board in Qld (or whatever they call themselves now) wanted each midwife to make an announcement about white privilege when they first met a patient?

    Sure, seems sensible. Now let’s make the fire brigade and ambos do it!

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