Australia Prepares for a Power Grid Without Spinning Turbines - Slashdot

›

• Stabilizing [separate issues]

  This particular work is about stabilizing the grid, not about power storage or baseload.

  Flywheels have also been proposed for power storage (I can remember flywheel energy storage work [osti.gov] back to 1980, but probably there's work much earlier)... but that's a different thing.

  • As batteries have become cheaper and more reliable, flywheels make less and less sense.

    • Scale up [Re:Stabilizing [separate issues]]

      I expect you're probably right (engineering rule: never bet against a technology that's already building millions of units in favor of one never demonstrated in actual use), but there may be scaling issues-- in general, a MW-day worth of batteries is about the same price per joule as a GW-day worth of batteries, but I'm not sure that flywheel storage might not scale up non-linearly.

    • The issue isn't the batteries, they can respond instantly, it's the inverters. They do not respond instantly. A flywheel or a rotating generator uses its own momentum to smooth out twitches in frequency. That is why a mechanical governor on a turbine is still fast enough to handle a surge in load without upsetting the frequency. The immediate deficit or surplus in energy available is made up by a very small change in rotational speed of several tons of copper and steel.

      I spent enough time in engine room upper level watching the governors work on the turbogenerators to appreciate how well that system works.

      • Re:

        The issue isn't the batteries, they can respond instantly, it's the inverters. They do not respond instantly

        Rubbish.

        A bit of background. A while ago Australia installed what was at the time the worlds biggest battery [cefc.com.au]. Not long after a coal fired generator dropped out, as in one cycle the are generating megawatts, the next cycle 50ms later it was gone. I'm not sure what your definition of "instantly" is, but to a computer and an inverter the 50ms AC cycle is an eternity. The battery was in another state,

  • Re:

    I hear the work on superflywheels for energy storage - lens-shaped fiberglass flywheels that stressed the glass fibers evenly to near their breaking point throughout the rotor, thus storing an amount of energy near that of burning that much silicon and oxygen into glass - was a casualty of the 3.2 billion settlement of the suit against Dow Corning over alleged harm from leaky breast implants.

• Re:

  If interia is all that you need...go find a few hundred politicians and ask them to get together to talk about it in endless rounds of discussions.

  Politicians being who and what they are will not achieve anything during these discussions no matter how much their press people claim "Progress is being achieved!".

• Re:

  There is your problem. The amount of material needed to build a battery bank large enough to cover the needs of whole countries is completely unrealistic. This is a case were the problem is worse than the solution.

  • Re:

    You don't need a battery back that large, not to provide inertia, any more previously you needed giant spinning flywheels to do the same.

    For inertial and grid balancing you need quite power which is a signficant percentage, but energy which is much smaller. Inertia is about changes happening over seconds. For intermittent power source balancing you need more energy, but also a variety of sources (which reduces intermittency) and interconnect.

    If you listen to some news outlets you will see people saying "bui

    • Re:

      'If you listen to some news outlets you will see people saying "building a battery to last two weeks would costs trillions". Yes, it would. But you don't have to.'

      You do if you want a usable supply. Look at the UK, I give the link all the time, where you can see in real time what's happening to wind generation there.

      www.gridwatch.co.uk/wind

      Two weeks calm is an extreme, though it does happen every couple of years. But one week is quite common. This has to be supplied somehow. At the moment its gas. If y

      • Flywheels are about percents and tens of seconds

        'If you listen to some news outlets you will see people saying "building a battery to last two weeks would costs trillions". Yes, it would. But you don't have to.'

        You do if you want a usable supply. Look at the UK, I give the link all the time, where you can see in real time what's happening to wind generation there.

        But flywheels are about providing power on the order of percentages of the load for times measured in seconds or less. A battery/inverter system that can handle a few percent of a region's load

        • Re:

          Indeed, some of the time-shifting battery/inverter systems already deployed in the utility grids, though providing little energy storage capacity compared to the grid size, are funded by fees paid for their activity as simulated inertia generators for grid stabilization. And/or had their construction funded for the purpose ditto.

  • Re:

    The amount of material needed to build inertial flywheels large enough to cover the needs of whole countries is even more unrealistic.

    Batteries have about 20 times the energy density of flywheels, and flywheels lose their energy much faster. They are best for smoothing loads over minutes or hours, not days or weeks.

  • Re:

    > The amount of material needed to build a battery bank large enough to cover the needs of whole countries is completely unrealistic

    Iron–air batteries are predicted to have energy densities of more than 250 Wh/kg (theoretical limit is 1200 Wh/kg) . Australia electricity usage per year is about 200 TWh, so hourly usage on average would be about 22830000000 Wh. So running Australia for 1 hour on batteries alone, would cost 91320000 kg of iron.

    World uses 1899000000000 kg of iron per year, so Australia

    • Re:

      I am gonna be honest, I hadn't followed that development, thanks for making me read about it! No errors found in particular in your reasoning, but I want to follow up on what you said.

      First, this technology is not yet in production, and I usually don't like to bet my future on unproven technology. Unproven in the sense that if the production really begins in 2024, we don't know how long it will take for it to ramp up so that it produces enough batteries... Also not taking into account the usual bugs/problem

  • Re:

    I believe batteries are already part of the plan. The point is not that you need to supply all grid energy from a battery. The point is that a battery plus inverter (both of which Australia already has and I am sure they will be investing in more) can stabilize the grid effectively just as conventional synchronous generators can. If you look worldwide at total energy usage including heating and transportation, it is pretty obvious that we cannot replace all fuel sources with renewables or electrical any tim

• Re:

  It is not needed today. Historically, it was a very reliable regulation mechanism and there were no real alternatives that could compete. Today, this can be done cycle-by-cycle in software controlling converters backed by batteries. It is high time this was put into production.

• Re:

  Battery DC, grid AC. The problem is in the interface, the inverter.

  Note that going from AC to DC is never a problem either, a big enough capacitor can smooth out AC transients to feed the batteries.

• Re:

  You probably would want to spin the flywheel with electricity rather than using some mechanical clutch.

  • Re:

    Thing is that they don't spin for that long before slowing down which could affect frequency. If you can keep the flywheels always going with electricity then why do you need the flywheel at all?

    • 1 hidden comment

    • • Re:

        Then you can just skip the flywheel altogether, right?

        • 1 hidden comment

        • Re:

          The flywheels acts as a capacitor, helping deal with transients and making smoother power output. Sort of like a "water tower" for electricity.

          I wish more research into supercapacitors could be done. Those have a lot of promise just because they store energy physically, not chemically, so there isn't anything that wears out or breaks down, and they can be charged and discharged at very high rates without damage.

    • Re:

      in my humble opinion, no. One does not think in terms of frequency when thinking of flywheels. If you need 50 or 60Hz AC, then you convert the energy from the flywheel to DC, and convert back to AC.

  • Re:

    I think these flywheels are just generator heads with the generator motor (prime mover) disconnected. They must have some extra inertia added to the rotor so they store some energy. They spin all the time when the grid is up. As soon as the grid goes down, the inertia keeps the generator head spinning. This would provide totally seamless instantaneous backup power.

    So I can see why it would be an attractive idea to just attach the prime mover to the flywheel with a clutch. But it is also probably a pretty

• Re:

  It's batteries. Eventually everything will be solid state.

  • Re:

    Not necessarily, flow-batteries are a thing. But a lot of stuff will indeed be solid-state because that massively increases reliability and decreases cost. Also, doing things like interfacing a HVDC long-range line to a local AC grid has been done solid-state for a long time now. This is not really new tech and it is not really experimental. Grid operators just have a tendency to be careful.

    • Re:

      Many flow batteries have been in development a long time or been completely abandoned. A workable hydrogen-bromine flow battery would be fantastic but it seems like solid-state lithium batteries are going to eat it's lunch before it's ready.

• Re:

  Grid-stabilization-only flywheels (when they're a separate machine rather than the inertia of an existing turbine/generator) are connected directly to an "electrical machine" (generator/motor) and spinning all the time. No clutches. When they need to bring additional generation on it's a separate device, connected to the grid purely by its own electrical switching.

  They're about keeping the phase and frequency of the grid from flapping around rapidly as the load varies in the short term, by storing and abs

• Re:

  They can easily replace all spinning turbines with battery supplied power. The Tesla Hornsdale battery power plant has been doing this for years. It provides millisecond response to power fluctuations (and has been making a lot of money providing this service.)
  Time to retire inefficient ancient turbine technology.

  • 2 hidden comments

  • Re:

    Yes. Because batteries can supply and also accept power, large grid connected inverters can be programmed to behave like giant spinning machines and thus stabilize the grid with fake inertia.

  • Re:

    First we need the patents to expire. That's too much dependency for a restricted technology

    • Re: Bad /. title; most renewable power uses turbin

      No restrictive patents on Tesla Power walls, etc.

  • Batteries store power, they do not generate it

    They can easily replace all spinning turbines with battery supplied power. The Tesla Hornsdale battery power plant has been doing this for years. It provides millisecond response to power fluctuations (and has been making a lot of money providing this service.)

    This is not accurate. Battery-supplied power must come from some source. That's usually solar panels or the power grid. The power grid comes from power plants. Spinning turbines are necessary components in most power plant formats, especially renewabl

• Re:

  Well, the issue is that the turbines are not synchronously coupled to the grid (not operating at 50 Hz or 60 Hz output frequency). Wind generators do not operate synchronously to the grid. The output is rectified and then fed to the grid through electronics.

  The traditional grid had giant spinning machines that provided a certain amount of inertia to the grid and helped keep all machines spinning at the same speed (if one tries to speed up, it will be forced to supply sufficient power to speed all of the s

  • Re:

    Yes, nice clear explanation. Why batteries work for frequency regulation.

• Re:

  Some years ago, at the COP 15 (Copenhagen Summit), there was a conference hosted by gas lobbyists. Interestingly, they were all in huge favor of "renewables" (wind/solar to be fair), and strongly against nuclear. Simply because they knew that was their way to keep selling that fossil fuel, as we do need some baseload...

  Sad to see all those anti-nuclears being manipulated by the fossil fuels lobbies. Sad to see those people calling themselves "Greens", working on behalf of those lobbies to emit even more CO2

  • Re:

    Fortunately for the Greens, Europe's warm winter has saved a number of them from being burned for heat.

• Re:

  My guess is they have no idea what they're doing. They are "preparing" by spending a lot of money to try to come up with solutions to a problem that so far has eluded one.

• Re:

  australia has plenty of data available too. https://opennem.org.au/ [opennem.org.au]

• Re:

  World will not end because it maintains a safe distance from the swirling event horizon that encases EEVBlog Dave's home in Aussie land./s

• Re:

  You need a better freezer motor, one which starts slowly and gradually builds up to full speed, so it does not require a big inrush of current to start. Such a motor would be complex, probably requiring a transmission.