Remember the choke point. How sustainable is renewable energy?

This is a draft of a chapter in the work in progress to explain why Wind and Solar power cannot replace coal and gas to provide reliable power until massive amounts of wind and solar power can be stored to use when the sun is not shining and the wind is low.

The key point is to take account of the choke point in the supply of wind and solar power. That is the lowest point, the worst case scenario. We have to plan for the worst case otherwise sooner or later large parts of the grid will go down, even whole states. How many times a year can we afford that?

It is potentially catastrophic to invest public money in windmills and solar farms before mass storage is available. The German Trifecta of Failure and the South Australian experience have demonstrated that.

The results of premature investment in intermittent or unreliable energy.

Power becomes more expensive.

The supply becomes less stable and less reliable.

The coal-fired power stations are driven out of business by subsidised renewable energy with favoured access to the grid.

This is happening in Australia and the situation will get a lot worse unless there is an effective plan to save the coal-fired power stations before any more are closed.

Two major misconceptions. One is the claim that RE has been getting cheaper and is now cheaper than coal-fired power. This can be addressed another time, the point is that the problem of the choke point applies regardless of the cost of RE.

The other misconception is that batteries and pumped hydro will solve the storage problem. This can be answered briefly.

The $60M battery attached to the ….windfarm in SA will supply power for 20 minutes after the wind stops. It would power the SA grid for 3 or 4 minutes. Calculate the cost of batteries to support the SA grid for a few hours or a whole day.

A wall of household batteries costing 10 or 12K will keep the lights on overnight, plus the fridge, charge your phone and boil the jug but don’t do any washing or run the air conditioning, or charge the two Teslas in the garage. They might set the house on fire as well! And how long do they last?

Don’t expect a miracle from pumped hydro. The way things are going several coal stations will be closed by the time Snowy2.0 is completed, even on the current timetable. That could take x GW out of the system and how much is Snowy 2.0 going to deliver? Remember that almost a third of the power that is generated by the wind and solar farms is lost in the pumping. How sustainable is that kind of waste? The preliminary estimate of the cost for Snowy 2.0 would deliver two modern coal-fired plants and you can guarantee that the cost will blow out by many billions of dollars and the time for completion will blow out as well.

How soon can be dispense with power from coal?

The short answer is that there is no quick way to eliminate coal-fired power. Audrey Zibelman, CEO of the AEMO the Australian Energy Market Operator, conceded that coal will be in the mix for some time but where is the plan to save the coal stations?

She has claimed repeatedly that we can win the Power Trifecta by getting cheaper power and more reliability with more renewable energy in the mix. This is a remarkable claim in view of the German Trifecta of Failure.

The daily cycle of electricity use and the sources of supply in South Eastern Australia.

This is the picture for the 24 hours up to 8pm Friday 16th. This is easier to read although of course it keeps changing. Still it shows 24 hours so you can get the picture however much the details change.

Key features.

1.The providers. Black and brown coal are the foundation of the supply. Brown runs at a steady level while Black rises and falls following the demand on the system. Natural gas and water (hydro) go up and down fairly rapidly as required. The supply from wind is highly variable and on this particular day it ranged from 60% down to 27% of plated capacity at the evening peak. Solar power of course comes and goes between day and night.

2.The daily cycle. There are peaks in the morning and the evening for breakfast and dinner. The evening peak is higher because in winter the heaters are on and in summer the air conditioning is likely to be turned up. The winter peak usually approaches 30GW.

3.The contribution of sun and wind at the peaks. Solar makes some contribution in the morning but none at the evening peak in winter.

The capacity problem. Managed and unmanaged load shedding

The AEMO issued a warning that a lot of capacity in the system has been lost in recent years. Some 6 or 8GW has gone in the last few years and Liddell is scheduled to close in 2022 or maybe 2023.

When the system lacks the capacity to provide the power that consumers want to use there is managed and unmanaged load shedding. First the system operator (the AEMO) contacts high volume users and instructs them to reduce their consumption. At the next state the operator blacks out selected suburbs or districts. If the managed load shedding is too little or too late the whole system or some substantial area blacks out – the whole of South Australia went for three days in 2016.

The fragility of the system is not well known. It would be better understood if the public could find out how much of the first stage of load shedding happens. There is a cost because the users are compensated and the price is paid by increasing the cost of power to users at large.

The Choke Point guarantees that Solar and Wind cannot replace coal-fired power.

The following figures address the situation at the winter peak of demand that is about 30GW after 6pm when the sun is off duty.
Supporters of RE might claim that the 6 GW of wind power that are currently being built or proposed in addition to the 6 GW existing will cover the loss of coal-fired power. Those figures come from this source and I thought that much more is impending, of course the situation changes so fast that figures are out of date by the time they are published.

Anyway, consider the amount of Wind required to replace the current supply of 18 or 19GW from coal. The other main providers are Water with capacity in the order of 5 or 6 GW and various forms of gas that add up to about 6GW and nobody is suggesting that the should go.

Now consider how much installed wind power is required to generate 18GW at the lowest point of wind supply – around 2% or 3% of plated capacity. Think of the analogy with drowning. When you are under water for five or ten minutes it does not help that for all the previous years of your life you breathed air with 20.95% of oxygen.

Even at 5% of plated capacity, a common enough reading, 18 x 20 = 360GW.

That is a scary figure compared with even the most inflated estimates of proposed Wind projects.

How much can Hydro and Gas ramp up when the wind dies?

Where is the fault in this line of argument?

Are they counting on nuclear power?

UPDATE. More figures to indicate the shortfall of wind. These are the percentage of the total load provided by wind at the evening peak over the last few days. To be fair we are not expecting wind to reach 100% because Water and various forms of gas are good for about a third of the 30GW demand. So just consider the gap between these figures and (say) 60%.

6, 2.4, 3, 2.5, 2.5, 4, 4, 5, 1, 5, 7.5, 5, 15, 16, 4, 10, 1.3, 6, 9, 7.

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44 Responses to Remember the choke point. How sustainable is renewable energy?

  1. Lee says:

    You have a big problem when ideologues, rent-seekers, banks, and morons are making important decisions on means of power generation, instead of electrical engineers.

    If you have a toothache, you don’t consult a plumber.

  2. Nob says:

    Hydro expansion is impossible due to national parks in the Snowies deliberately placed to prevent the very dams that could increase capacity.

    To say nothing of the Greens and Labor (with Lib collusion ) economic vandalism in Tasmania preventing the Gordon dam thus ensuring Tassie dependence on coal.

  3. Ben says:

    AEMO is assuming that by 2040, 38.5 GW of wind and solar plus 17 GW of storage will replace 14 GW of coal fired power and 1 GW of flexible gas. On this trajectory renewables would be generating close to 50% of the NEM’s annual supply.

    That’s straight out of the AEMO ISP.

    That’s a plausible generation scenario (don’t forget the spectre of demand management), but it’s expensive. Very expensive.

  4. Rafe Champion says:

    What do we get from 38GW of wind and solar at night with the wind below 5%?
    What is this about 17GW of storage? Actually I saw that and forgot about it. They should talk to Bill Gates.
    More to the point in the immediate future, what is the plan to save the coal stations from the predatory RE providers?
    Not to mention the question, why would we bother do do all this given that even the Chief Scientist knows it makes no difference to the planet?

  5. Ben says:

    Over the course of a year, 38.5 GW of intermittent power at 26% utilisation can supply 90 TWh. But intermittency implies shortfalls, and demand includes peaks and troughs, hence the storage and lots of it.

    Take a look at this TransGrid presentation, there is a graph showing the dispatchable generation shortfall out past 2040. It helps to put the totals in perspective.

    The AEMO 2019 ISP scenarios are documented now on their website. It’s worth looking at to understand what they think will happen.

    I believe we are headed for high costs, increasing blackouts, and eventually nuclear.

  6. Ben says:

    Rafe, you are right of course, that wind and solar can’t support the grid. Not even installing 4x or 10x the grid demand.

    Everybody knows that batteries can’t fix it, everybody knows that we can’t build enough dams and hydro.

    Unless there’s a bolt from the blue and we get a couple of new coal power stations, then the only dispatchable power we’ll get is gas, and that means high wholesale prices are here to stay, except for the periods when rooftop PV sends prices negative.

    Then there’s the added costs of extra transmission to connect all the wind and solar, the synchronous condensers to keep it stable, the communications and software to get all the VPP running, the ongoing and increasing quantities of weather stations and modelling required to keep the forecasting models within 300MW of actual output to prevent blackouts in the looming shadow of a system of ever increasing complexity and fragility.

  7. Rafe Champion says:

    Yes they say things like “X Wind Farm will provide power for 150,000 houses”. How much power and how many days of the year? What about some businesses with fridges and ovens? And so on.

    And they seem to be blind to the choke points.

  8. Dr Fred Lenin says:

    How do you solve the lack of power due to cloud ,darkness and calm weather ? You build more windmills and solar power “farms ,”of course !
    The whole thing is a scam, you try to replace proven reliable 24/ 7 supply with a totally unreliable fluctuating system that needs to be highly subsidised to survive .
    The people advocating this are traitors criminal scammers or absolute cretins .
    The crony capitalist globalist communist fascists need to be consigned to the pages of history ,the day is coming ,they are too arrogant with this monumental scam ,treating their benefactors with contempt .
    Their benefactors are the taxpayers they despise who keep them in luxury .

  9. Tekweni says:

    You are all wrong. Turnbull explained clearly today that there is no future in coal. And as we all know everything he says is gospel.

  10. Nob says:

    #3133466, posted on August 16, 2019 at 10:18 pm
    You are all wrong. Turnbull explained clearly today …


  11. Dr Fred Lenin says:

    Turnball ? Isnt that some kind of snake who s habitat is the north shore of Sydney ?

  12. Rohan says:

    RET, LRET, VEET and any other crony capitalism is now 2c/kWh in Victoriastan. Or 5.7% of power costs.

    Not bad when the subsidy is an additional 20% of total generation cost. Is that what they mean by value adding?

  13. RobK says:

    Distributed grids require a lot of redundancy. Distributed grids have many more potential points of failure.
    Distributed grids are complex and expensive to maintain, administer, control or predict. Distributed grids are labour and materials intensive. All the above applies doubly so for renewables.

  14. Howard Hill says:

    The people advocating this are traitors, criminals and scammers or absolute cretins.

    I fixes it.

  15. Scott Osmond says:

    They always talk about how many houses wind/solar plants will power. Never how many cold warehouses, bakeries, smelters, factories and many other power guzzling activities that don’t have a thing to do with residential use. Next time around the barbie some clown talks about x number of houses point it out and see how quickly the subject is changed.

  16. Mark M says:

    “At UN Environment, we believe that sustainable energy presents an opportunity to transform lives and economies while safeguarding the planet.”

    “Safeguarding the planet.”

    No amount of solar or sea breeze collectors will ever do that. Ever.

    Yet discussing the merits of renewables continues as if it is viable at some point, somewhere.

  17. bemused says:

    Two major misconceptions.

    They are not misconceptions, they are outright lies and need to be called out as such. Diplomacy just won’t cut it anymore.

  18. Nob says:

    Renewables are racist.

  19. I_am_not_a_robot says:

    There is an easy way to determine the viability of so-called renewables by examining the fundamentals and a hard way through bitter experience.

  20. Rob says:

    Every journalist in Australia should be required to read this message and all the included links.
    It would also be of huge benefit if our education system used it as source material.
    Ignorance is a wonderful and dreamy space to inhabit – choke points are the looming reality.

  21. Dr Fred Lenin says:

    Nob, renewables are racist ,persecuting white people ,Shame Shame ,as Kiwi darling hunch would say.
    One day there be a reckoning ,and there will be much weeping ,wailing and gnashing of teeth amongst the woukd be eelites . Serves the bastards right .

  22. Mic hael K says:

    I will pay attention to the left when it embraces nuclear power.

  23. John Constantine says:

    It is fully intended that demand management will dynamite australias remaining grid dependent industries.

    We are looking the wrong way by asking how we can keep going as we are with ruinables.

    Our elites have signed us up to their donor’s unswerving demands for the utter capitulation of the racist settler industrial anglophone outpost that was australia.

    If we want to clearly see our future, we need to sit down and feed into our calculations exactly what economy and society can run when Big Australia has ten millions in melbourne and ten millions in sydney with windmills and no fossil fuels.

    Rationing and two economies, their elite economy with Davos style billionaire living standards, and the Cheerful Squalor for the tens of millions of proles that are the feedstock for the revolution.

  24. mem says:

    Some additional comments
    Wind doesn’t work when the wind is too strong or buffeting
    At present the three southern states are getting major feed-ins from two sources. Tas hydro and Qld coal. A drought in Tas or failure of connector cables could bring down the Tas system. Similarly if anything happens with Qld coal supplied electricity NSW, Vic and SA will crash. All it would take is a major flood or other non predictable natural disaster.
    Snowy hydro 2 will not generate electricity. It takes existing electricity out of the grid and pumps water up so it can be used when electricity is short and expensive. In the process it loses lots of energy and consumers pay more.

  25. Herodotus says:

    And this whole disaster is based on the false premise that CO2 is warming the earth and it must be curtailed.
    Heads should roll.

  26. tgs says:

    Audrey Zibelman, CEO of the Energy Authority

    Minor nitpick.

    Had to look this up because I had never heard of the ‘Energy Authority’. Might be worth replacing this with AEMO.

  27. Fat Tony says:

    #3133669, posted on August 17, 2019 at 9:19 am
    And this whole disaster is based on the false premise that CO2 is warming the earth and it must be curtailed.
    Heads should roll.

    No it isn’t. It’s never been about the science – never.

    It’s always been about the money and power.

    As the old saying goes – some people would rather rule over Hell than serve in Heaven.

  28. mem says:

    Electricity Emergency Crisis Management
    Given the fragility of our new electrical system that is balanced on a knife edge I would like to recommend that every household, business and institution in Australia be required to develop an emergency plan for both short term and long term electricity outages. (Similar to developing a bush fire plan). community meetings need to be convened by every council and each municipality should employ an emergency electricity blackout officer. Each state should establish an advisory body of experts and community members to advise government and community on the latest development and generate media notices and undertake research into the latest means of dealing with the problems created by such an emergency. federal and state grants could be given to universities for research and tertiary institutions should be encouraged to set up emergency electricity study centres.
    Areas that will need to be addressed include the following:
    Immediate crises management (the first 24 hours)
    Food safety,storage, processing and retailing
    Transport and traffic management (public and industrial for food and other essential supplies)
    Employment and labor issues
    Hospitals and emergency services procedures including waiting list management
    Public events management
    Just to name a few.
    Given the impending emergency which is likely to occur within the next 24 months these procedures should be implemented immediately and given full Government support.

  29. Roger says:

    Similarly if anything happens with Qld coal supplied electricity NSW, Vic and SA will crash. All it would take is a major flood or other non predictable natural disaster.

    Or a political disaster like Palaszczuk & Trad:

    50% renewables by 2030.

    More large scale renewables projects than any other state (most a long way from population centres).

    Coal written off as too expensive.

    So, some time before 2030 QLD will no longer be able to prop up the eastern grid.

  30. Roger says:

    Coal written off as too expensive.

    Though we’ll continue to sell it to China, India & Japan.

    How else would we finance all those state government renewables subsidies?

    The idiocy runs strong in our leaders.

  31. Elderly White Man From Skipton says:

    I often entertain myself with ideas about energy. But then I realise that we actually don’t have a policy of any kind. So I spend my time designing a highly efficient house that will be situated on my land very close to a very good train service. I’m becoming fairly confident that energy costs are going to be the wrecker of this economy.

  32. Frank Walker from National Tiles says:

    Elderly White Man From Skipton
    #3133843, posted on August 17, 2019 at 12:41 pm

    I often entertain myself with ideas about energy. But then I realise that we actually don’t have a policy of any kind. So I spend my time designing a highly efficient house that will be situated on my land very close to a very good train service. I’m becoming fairly confident that energy costs are going to be the wrecker of this economy.

    In other words, you’re a delusional fantasist.

  33. Rafe Champion says:

    Sounds like a plan to me!

  34. Nob says:

    The nearest “very good train service” to Skipton, Victoria is in Singapore.

    Fossil fuel powered Singapore.

    95% gas generation. 1% oil, 4% waste burning.

    But I guess elderly man is from, not in, some Skipton, whether in Victoriastan or Englandshire.

    No “very good train service” anywhere is powered by reliance on wind and solar.

  35. Muddy says:

    #3133751, posted on August 17, 2019 at 10:48 am.

    Yes. Rafe, this is a good issue to push. From the domestic point of view, what life-saving or life-enhancing medical devices are dependent on electricity? CPAP machines? What else?

  36. David Brewer says:

    Remember that almost a third of the power that is generated by the wind and solar farms is lost in the pumping.

    They nearly one-third losses are not just from the pumping, but also from evaporation in the dam and reconverting from kinetic energy to electricity on the way down.

    However, the losses are not really the point. The energy to be stored in Snowy 2.0 would have been waste anyway. Its capacity will be far below the waste wind (and solar, though this is more predictable) energy that will be available if wind farms continue being built.

    The economics of Snowy 2.0 and wind are messy. Basically you have two products involved:

    1. straight wind power, which is virtually worth nothing, since the product demanded is not a quantity of megawatts but a reliable 24/7 availability of electricity.

    2. hydro power, a much more valuable product because it offers a reliable and controllable supply.

    Economically you have a complex calculation. Snowy 2.0 is effectively raising the capacity factor of the wind turbines, and also raising the average value of each percentage point in this capacity factor. On the other side you can only raise the capacity factor so far – since you have to stop when the dam is full and the dam turbines are running full blast. And you must also deduct losses of energy in the process and all the other costs involved including the transmission lines to get the power from the wind farms to the dams, transformers, pumping equipment, and increased maintenance on the hydro facilities from running them harder.

    Earlier posts disclosed that Snowy 2.0 was assessed decades ago and rejected as not economically viable. But that was before we wasted tens of billions of dollars on unstorable and uncontrollable energy. And if we keep on wasting money on this virtually worthless product, at some point Snowy 2.0 must become viable.

  37. Rafe Champion says:

    I don’t see how it will every be viable in terms of a return on the capital invested. Unless the power price is so high that the country will be bankrupt on power bills. And then who will buy it?

  38. twostix says:

    I was talking to a guy a while back who works for one of the big energy companies. He was on a project where they were going to pay to put automation into high rises in the cities to remotely run their backup generators at peak demand to make a profit.

    To save us from fake pollution they’re going to re-smogify the CBD’s!

    I was astonished at this insanity.

  39. mem says:

    My neighbors cut down all the trees on the north and west sides of their house so that they have more sunlight on recently installed solar panels. You do wonder at the logic. The house will now be a hotbox in summer and need more energy to cool! Plus their adjacent neighbors no longer enjoy the shade or the shelter from the frost in winter. I would love to know if anyone has done a study on the energy impact of the number of trees lopped and the impact on heating/cooling a building.

  40. max says:

    Power Grid Chaos Jolts Texas On Friday, Energy Costs Triple Amid Heat Wave

    The state’s power grid operator that serves most of Texas declared an energy conservation emergency for the second time this week, the first on Tuesday when temperatures exceeded 100 degrees, and customers cranked up their air conditioners to escape the heat.
    Refinitiv data shows next-day power prices at the ERCOT North hub jumped from $265 per megawatt-hour (MWh) on Thursday to $751 MWh by Friday morning, the highest-paid per MWh in almost a decade.
    Real-time prices soared to ERCOT’s $9,000/MWh offer cap for several 15-minute intervals for a second time this week, said Reuters. Refinitiv data said it was the fourth time prices hit that cap after January 2018, May 30 and Aug. 13.
    The jump in energy costs shows just how unpredictable the Texas power market has become as coal-fired generators are retired for cheaper natural gas and renewable energy sources.

  41. Rafe Champion says:

    Thanks Max!
    I imagine that anyone who understood the way the grid works would have predicted that kind of thing in advance. What do they have computer models for?
    The problem is that the mandates to use RE in preference to coal power are embedded in legislation and not enough people understand what is going on to get effective political action.
    We have to find how to explain this in the simplest possible way so people in the street can understand.

  42. Lee says:

    My neighbors cut down all the trees on the north and west sides of their house so that they have more sunlight on recently installed solar panels. You do wonder at the logic.

    That’s the same sort of moronic “thinking” as the idea that gathering the materials for, and the production of, even more solar panels and wind turbines won’t result in an even greater “carbon imprint” and for far less efficient results.

    Or cutting down whole forests for biofuels to replace coal.

  43. classical_hero says:

    Unicorn farts would be more environmentally friendly.

  44. TonyfromOz says:


    I should have that list of dates in a week or so, maybe sooner.


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