David Bidstrup guest post. Two green days

This post follows from my post of a couple of days ago. The object is to see how much more solar and wind capacity would have been required to meet the peak demand on January 18 and 19 2018 without the dreaded “carbon emitting generators”, i.e. coal and gas.

The demand curve has been modified by removing the Hydro contribution, on the assumption that hydro is still allowed as a “carbon free” source. The next step is to find the scaling factor needed to boost wind and solar at the capacity factors that pertained on the days, focussing on the 5 minute intervals that the records provide.

After finding the maximum scaling factor needed to meet the peak demands I then found the necessary “installed capacity” for wind and solar. After that I calculated the theoretical output from the scaled up versions using the capacity factors of the day and found the overcapacity that would apply at lower demands.

The scaling factor is 45. This is the maximum found and it sets the size of the facilities needed to meet the peak demand.

This increases the wind from 6,157 MW installed capacity to 275,789 MW and solar from 2,693 MW to 120,627 MW.

The chart below plots the scaled up output against the demand curve minus hydro. Remember that there are 288 5 minute periods in one day.


The first thing to note is the massive overcapacity of the system at demands lower than the peak. The thick black line is the demand less hydro curve and the green area shows the theoretical output of the scaled up renewables. Before anyone says that the answer is to “store the excess” it needs to be understood that there is no such thing as excess electricity. Demand drives the system output so anything above the black line is illustrative only and serves to highlight the overcapacity the system needs to be “carbon free”.

This “excess” above the actual need gets even worse on days of lower demand because the installed capacity of the wind and solar installations are fixed. The only solution is to turn some of them off.

This study is illustrative not definite. The RE boosters, climate change loonies and carpetbaggers will argue that the system can be managed by judicious use of “storage” but they never define the quantum. If the purpose of an electricity system is to produce reliable and inexpensive energy for society to function properly and for businesses to thrive then RE is probably the most insane way of going about it. As always it is the details that get in the way.

The other day Judith said I was “fighting the last war” but I prefer to think of it in terms of battles won and lost in a continuing war against idiocy.

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13 Responses to David Bidstrup guest post. Two green days

  1. RobK

    The point you make is a very valid one that is difficult to get across. I have tried for a long time to communicate it but for the most part unsuccessfully, I expect.
    I have tried by saying there are always droughts and gluts, pretty much irrespective of the amount of storage or alternative loads(eg desalination, pumping etc) that over build can utilise. The reason is that the random, sporadic nature of RE means the utility of the storage or alternative use isn’t going to be economic much of the time as that capex is also at the vagaries of RE gluts and droughts.
    I have learned this from running off-grid business for many decades. You simply can’t build enough generating capacity and enough useful load-dump capacity to harness the gluts or store for the droughts.
    The load in an RE drought has to be met at some point by redundant non-RE. The power rating of the redundancy is in the order of full load demand. The energy delivery capacity is dependent on stored capacity and the factors of safety deemed acceptable.
    The RE champions just don’t acknowledge that conventional fuels are of a stored form and supply is generally measured in years or decades.
    This is very applicable to the H2 proposals going about at the moment. How much RE over-build will be required to service a particular H2 demand, how much storage do you over-build, how much production capacity do you over-build. It’s a moving feast.
    The point is illustrated by the article in der spiegel I posted a long time ago where small pumped hydro plants in Germany were going broke due to RE vagaries, after running profitably for 100 years on predictable baseload shaving.
    The H2 business will have a great difficulty juggling production and demand. So will Snowy 2.0.
    There will be subsidies on-going until we learn to walk away.

  2. win

    Unusual cold westerlies blowing in Brisbane during the night. This is the second year we have had cold dying winds , I suppose these conditions will be added into the wonderful world of wind power as a constant.
    Did any one notice that Dan Andrews used computer modelling for his Corona virus lock downs. It was just a sentence tacked on to a report from the Hotel Quarantine fiascoe.

  3. Bruce of Newcastle

    Thanks David for an excellent post!

    The load in an RE drought has to be met at some point by redundant non-RE.

    RobK – Exactly. In other words even with massive overspend on wind and solar you still have to spend exactly the same capital cost on baseload backup generation than you would if you didn’t have the solar or wind energy. But the ROI on that backup baseload would be abysmal since it only operated on bad renewable days, to keep the lights on. It would have to be subsidised or no one would build it.

    And you can’t just let the grid go into blackouts on low wind/low solar days because of everything from refrigerators to hospitals that have to stay on. Not least the internet as well.

    And if the backup generators are not provided by the grid operators then everyone will go out and buy diesel generators – thereby just shifting that capital expenditure and CO2 emissions out into the economy.

    So then government would have to ban generators. But allow critical ones. It’d be a mess of Biblical proportions.

    The net result of all this capex is a vast increase in electricity price as the producers valiantly try and get a return to pay for it all.

    Then all those wind farms will need replacement every 20 years, rather than every 50 years for coal/nuclear.

    And on top of David’s numbers electricity generation would have to double at least to handle conversion of cars and trucks to electric.

    The whole thing is so completely insane that it must give grid engineers nightmares.

    And all of it is for nothing, since CAGW isn’t happening in the real world data.

  4. Mooka

    Would it be cheaper to cut out the wind and solar middleman and just convert coal powered generators to burn cash?

  5. Rafe Champion

    Thanks for that suggestion Mooka, it works well in conjunction with New Monetary Theory so you just have to keep printing more money. Scomo might be able to find a few lazy millions to put into the technological road package to develop a way to use virtual money as fuel to generate virtual power.

    Back in the real world, the point that David and RobK are making is more or less what I was trying to convey using the language of choking or drowning when we are killed for lack of air reaching our lungs.

    When we choke or drown we die for lack of air at the time and we are not sustained by the average amount of air that we breathed in the previous years of our life.

    None of the calculations for the future of RE take account of the frequent and prolonged wind droughts that are well documented by the output of wind power from the thousands of windmills across the entire nation. Incidentally at this moment there is not enough wind for the widget to measure in WA where the wind supply is buried in the 13MW of Other in the total supply of 1500MW.

    Across the SE wind is contributing 16% of the supply and lately in the middle of the day RE in total has got over 40% but that is not the point because the sustainability of RE has to be judged by the minimum supply (the weakest link in the chain) and not the high points or the average.

    The only way out of that is outside assistance (extentension cords) or storage.

    The end result is that we need 100% of conventional power to run the show until the storage issue is resolved. Don’t hold your breath waiting.

  6. Bruce

    Can anyone tell me how to store Three Phase Alternating Current?

    And don’t start with the perpetual motion machine of “Pumped Hydro”.

  7. Eyrie

    Did any one notice that Dan Andrews used computer modelling for his Corona virus lock downs.

    Someone had an Excel spreadsheet on their PC?

  8. duncanm

    Bruce – I assume you’re being deliberately obtuse here. There are many ways to store energy, but they mostly involve conversion to some other form.

  9. Michael Bowden

    Please help me out here!

    Consider this scenario:
    Constant demand is 100 MW
    I build a wind farm with a plate capacity of 100 MW ( forget the Capacity Factor issue in this scenario)
    The wind fails and the output of the wind farm falls to zero
    The lights go out
    Therefore I decide that I must have a conventional generator (gas say) to meet the 100 MW demand whenever the wind farm’s output is less than 100 MW
    I build the gas plant and find that I am constantly varying its output as the wind swirls around
    I start to lose money on my gas plant
    I go to the government and plead for a subsidy which, of course, is forthcoming
    Now the total costs include the wind farm, the gas plant and the subsidy (plus, of course, the O&M costs for both the wind and the gas plants)
    How is it then that renewable energy is cheaper than conventional energy?

  10. Kneel

    “There are many ways to store energy, but they mostly involve conversion to some other form.”

    Kinetic – flywheels etc.
    Potential – hydro etc.
    Chemical – batteries etc.

    At grid scale, all of these are dangerous – flywheels disintegrate, sending heavy things in all directions at high speed; dams collapse, flooding large areas; chemicals leak, causing fires and poisoning living things.

    These are secondary energy sources.
    We need primary energy sources – coal, oil, gas, nuclear, wind, solar etc.

    We need dispatchable sources – available when required.
    We need scalable solutions – what works at household scale may not work at grid scale and visa-versa.
    We need economically sustainable solutions – if it can’t survive on the value of it’s own utility, it’s useless.
    We need not just Return on Investment (ROI) , but also Energy Return on Investment (EROI) – there is no point consuming 1GW/h to build a machine that will produce even 3GW/h, we need about 5:1 EROI, or it’s not sustainable.

    One of the big advantages of fossil fuels is that we have lots of experience with them – they are well characterised in terms of risks, consequences, remedial actions and so on. We know we can’t leave a big pile of coal on the ground without tamping it down and watering it, or it will catch fire spontaneously, for example.

    None of this is new, it’s all well known and people deal with it every day – you might not have known some parts, but the people who run and manage these systems do know and over many years have developed rules and procedures to maximise efficiency and minimise risks – something RE has yet to address.
    Is wind “eco-friendly” when the turbine blades are a composite material that can’t be recycled, the generator itself requires rare-earths that exploit the poorest in the world, and the structure requires hundreds of tonnes of steel and concrete, while producing only a tiny fraction of what the same resources applied to a fossil fueled generator would produce?

    If you want to move away from fossil fuels, the only primary source that fits the bill is some sort of nuclear energy. Nothing else fits the requirements. Either thorium based fission, “fast breeder” plutonium fission, or some form of fusion (thermal like Tokamaks, or LENR like IEC). Either that or give up your cities, your mechanised transport, your overseas and interstate holidays, your cheap TVs and phones, your cheap food and water, your HVAC, your cheap telecommunications and the vast majority of jobs that aren’t based on physical exertion. IOW, back to the lifestyle of the 1800’s or earlier, where the majority of your existence is devoted to keeping yourself and your family alive right now – where you live and are treated as livestock; where you are a disposable and replaceable cog in the machine of society; and where progress has not just stalled, it’s been undone.

  11. RobK

    And if the backup generators are not provided by the grid operators then everyone will go out and buy diesel generators –
    Last year I spoke to someone who owns a business supplying compressors and gensets to the oil and gas industry here inWA. He was perplexed at the recent uptick in enquires for small natural gas gensets from out side their normal clientele. No surprises there really. Those who can afford it will have lights and aircon.

  12. Rafe Champion

    This week serious ALP divisions over energy policy surfaced again. Joel Fitzgibbon was called ‘The idiot for Hunter’ by one of his colleagues. On the other side, the very green Minister for Climate and Energy was described as “useless as a vegan in a butcher’s shop.”

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