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Australia Power

Tesla Big Battery Outsmarts Lumbering Coal Units After Loy Yang Trips (reneweconomy.com.au) 347

The Tesla big battery is having a crucial impact on Australia's electricity market, far beyond the South Australia grid where it was expected to time shift a small amount of wind energy and provide network services and emergency back-up in case of a major problem. From a report: Last Thursday, one of the biggest coal units in Australia, Loy Yang A 3, tripped without warning at 1.59am, with the sudden loss of 560MW and causing a slump in frequency on the network. What happened next has stunned electricity industry insiders and given food for thought over the near to medium term future of the grid, such was the rapid response of the Tesla big battery to an event that happened nearly 1,000km away. Even before the Loy Yang A unit had finished tripping, the 100MW/129MWh had responded, injecting 7.3MW into the network to help arrest a slump in frequency that had fallen below 49.80Hertz.
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Tesla Big Battery Outsmarts Lumbering Coal Units After Loy Yang Trips

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  • AC frequency (Score:5, Informative)

    by ebcdic ( 39948 ) on Tuesday December 19, 2017 @03:07PM (#55770455)

    For the benefit of Americans reading: the nominal AC frequency in Australia is 50Hz, not 60Hz.

    • Re: (Score:2, Funny)

      by Anonymous Coward

      Also, in Australia, electricity flows out of the negative post on the battery, through the attached circuit, and into the positive post

    • Re:AC frequency (Score:4, Informative)

      by Thelasko ( 1196535 ) on Tuesday December 19, 2017 @03:27PM (#55770631) Journal
      For those that don't know. The frequency of AC power is an indicator of the supply and demand status of the grid. The frequency is determined by the speed of the generators at the power station. If there is too much load on the generators, they slow down, and the grid frequency drops.

      The Australian grid is targeting 50Hz, and had dropped to 49.8Hz.
      • by TWX ( 665546 )

        So if I interpret right, the extra supply (from the battery) meant that the generating station didn't bog-down and the grid was able to ramp-up to 50Hz again.

        • So if I interpret right, the extra supply (from the battery) meant that the generating station didn't bog-down and the grid was able to ramp-up to 50Hz again.

          Reading TFA, it seems the other generating stations didn't bog down as much as they could have. The grid was short ~500MW, and the Tesla battery can only make up ~100MW. It just stabilized the grid a bit until another generator could be brought online.

          • Re:AC frequency (Score:5, Insightful)

            by AK Marc ( 707885 ) on Tuesday December 19, 2017 @04:06PM (#55770971)
            Electricity grids are stacks of eggs balanced on their point. A single snow event taking out a single line in the US took out millions of people for days, in a very populated and "modern" area.

            The Australian grid may have failed. The current was out of spec. If protection circuits activate, they'd shut down the grid. Tesla didn't fill all the missing need, but injected enough power in an "our of spec" event to ensure the grid couldn't fail from that event.

            That small boost may have saved a major catastrophe. We may never know. But that it could is a great proof of concept. Battery-based storage can react faster than anything else on the grid, to smooth grid failures to prevent cascades. Now we know, we need them all over the US, before the next snowstorm in the North East.
          • The grid wasn't short 500MW, it was down a 500MW power station.
            Since the battery only needed to supply 7MW to correct the frequency, the grid was only short 7MW.

            To say it was short 500MW would be assuming every power station running before the incident was running at maximum capacity. If that were the case, the back-up stations would have already been bought online.

        • Re:AC frequency (Score:5, Informative)

          by Orne ( 144925 ) on Tuesday December 19, 2017 @04:12PM (#55771031) Homepage

          Not quite. The original coal plant tripped, so the power that it was injecting ceased to be. In the very short term (tens of cycles), the energy demand on the system outweighs the supply, and frequency begins to drop. The remaining synchronized generating resources next engage "primary frequency response", which is an automated (governor) response that temporarily increases the output of the generators. By governor, there is a device in the generator controller that regulates the steam pressure to keep the rotation constant, so the energy imbalance creates mechanical drag that the governor attempts to correct. Each generator twitches up a tiny amount, the frequency decline is arrested, and the system stabilizes. You then have secondary systems that engage that drive the system back to a pre-loss state.

          The battery in this contributed primary frequency response, as a direct response to the observed low frequency. In the United States, Energy Storage devices are not required to provide primary frequency response, since almost all frequency response is provided by steam units. As more coal plants are retired and replaced by Wind and Solar (inverter-based units), the US grid will need to adapt and modify its requirements.

      • For those that don't know. The frequency of AC power is an indicator of the supply and demand status of the grid. The frequency is determined by the speed of the generators at the power station. If there is too much load on the generators, they slow down, and the grid frequency drops.

        The Australian grid is targeting 50Hz, and had dropped to 49.8Hz.

        .2 Hz is 0.4 %

        How robust would a grid be if it was designed to run at 200 mHz? Would it flatline (DC) when there's a power loss? Or would it still just lose 0.4 %?

  • by Snorlax ( 149527 ) on Tuesday December 19, 2017 @03:09PM (#55770473)
    The resiliency of the power grid would be vastly improved if we put a battery pack (the size of a normal intermodal container) at each substation. These could act like your home UPS, fixing blackouts of a few minutes, when they occur. This also would make the grid much more able to use wind and solar sources, without so much need for standby diesel systems currently in place.
    • The resiliency of the power grid would be vastly improved if we put a battery pack (the size of a normal intermodal container) at each substation.

      The resilience of the power grid would be vastly improved if we put a battery pack (the size of a normal outdoor dunny) at each house.

      • by TWX ( 665546 )

        Those dunny things are terrifying. [shopify.com]

      • by AK Marc ( 707885 )
        That's what the Energy cabal fears. If everyone had rooftop solar and a battery (The size of a Tesla battery is fine, and that's much much smaller than a dunny), then there would be no need for central generation of base load.
      • by dj245 ( 732906 )

        The resiliency of the power grid would be vastly improved if we put a battery pack (the size of a normal intermodal container) at each substation.

        The resilience of the power grid would be vastly improved if we put a battery pack (the size of a normal outdoor dunny) at each house.

        At what cost? Is it worth spending billions of dollars to reduce average downtime from 200 minutes a year [eia.gov] to some marginally smaller number?

    • The resiliency of the power grid would be vastly improved if we put a battery pack (the size of a normal intermodal container) at each substation. These could act like your home UPS, fixing blackouts of a few minutes, when they occur. This also would make the grid much more able to use wind and solar sources, without so much need for standby diesel systems currently in place.

      No, it would not be vastly improved since it is already very resilient in most places. Drastic improvement can happen where resiliency is an issue, which is not in very many places at present

    • by ArhcAngel ( 247594 ) on Tuesday December 19, 2017 @04:15PM (#55771049)
      Until VERY recently this was not at all economically viable because the cost to store the electricity was higher than the cost to generate it. I work for the largest owner of wind energy in North America and for years they would routinely short their windmills electricity production directly to ground because the grid from their location in West Texas to Dallas where it was needed was saturated. If they had stored the electricity the cost of generation + storage would have meant they would have to sell it at a loss. Now that storage costs can beat peak rates you'll see large companies invest in electricity time shifting so they can charge the battery when electricity is cheapest and switch to battery during peak usage to save money. This will benefit the grid directly since it will lower the stress during peak usage overall.
    • by dj245 ( 732906 )

      The resiliency of the power grid would be vastly improved if we put a battery pack (the size of a normal intermodal container) at each substation. These could act like your home UPS, fixing blackouts of a few minutes, when they occur. This also would make the grid much more able to use wind and solar sources, without so much need for standby diesel systems currently in place.

      This is really not necessary. The number of blackouts that have been caused by generation issues is miniscule. The last major one in the US was in 2003 and protections against such events have been greatly improved since then.

      The most cost efficient way to connect the battery would be to tie into a power plant transformer, or a substation, which would not eliminate any failure modes. The substation still would need protection controls that shut it down in the event that downed wires are detected. Blac

  • by NEDHead ( 1651195 ) on Tuesday December 19, 2017 @03:10PM (#55770487)

    When is Musk going to stop making big promises and then following through?

    He sure is a bad politician.

    • When is Musk going to stop making big promises and then following through?

      He sure is a bad politician.

      Well, we're not on Mars yet, despite what this (pretty good) television show [wikipedia.org] make make us think.

  • by Charcharodon ( 611187 ) on Tuesday December 19, 2017 @03:16PM (#55770541)
    ....and yet it does.

    Trying to remember why it wouldn't have worked. Because it might steal their market share? Yeah pretty sure that was their reason they didn't think it would.

    • by TWX ( 665546 )

      That's usually the reason why someone in a position of power criticizes a new idea from someone having demonstrated technical proficiency in their sphere of influence.

    • by Altrag ( 195300 )

      It could be more benign (and egotistical) than that.. "if it worked, we would have thought of it long ago because we're so good at things!" Of course "worked" in their context still means "generates a huge profit" rather than "technically feasible" but still..

  • I'm not sure how this is suppose to be amazing considering most computer folks at home who care about their systems use a UPS. I can see how not having a UPS and losing power at a key point might be a small disaster. Probably the only amazing part is that there are few systems that approach this size and scope but aside from that nothing new.

    • by ElBeano ( 570883 )
      Don't you mean Pro Climatic?
    • by torkus ( 1133985 ) on Tuesday December 19, 2017 @04:10PM (#55771007)

      Grid level power management is utterly unlike your home UPS.

      I think the article is overstating a bit given the scale, but the macro implications are impressive. Grid-scale generators are slow to ramp up and down - minutes to hours (or even days for startup of nuclear plants). Small, less efficient generators handle the small peaks (oddly enough, called peaking generator) that go beyond baseline generation and any under-utilization goes to waste so it's a careful balancing act. And even the peaking generators aren't instant response whereas the Tesla Battery IS essentially able to go from 0-100MW in moments (they should advertise this along with the Tesla speed records). This allows highly efficient supply of peak-demand (or, in this case, unexpected demand) which is pretty much unheard of.

      Having 500MW go offline suddenly does Bad Things to the overall grid. Remember when one plant tripped offline ... I think in upstate NY and blacked out most of the northeast in a cascade failure several years back? Having something able to take a near-instantaneous load, even for a few minutes, is a massive benefit.

    • by mspohr ( 589790 )

      This is fundamentally different from a UPS. A UPS takes over and provides power to a load when the mains supply is lost. It disconnects the mains power and generates its own.
      The Tesla battery pushes power to the grid when the grid is overloaded and unstable (as manifest by a drop in frequency). Adding power to the grid stabilizes it and prevents shutdown.

    • There are exactly zero other systems that approach this size and scope. That's the reason for the story.

      This is the world's biggest grid-connected battery, and it works as advertised, if not better. It may be particularly craven of me, but that seems to be rare with infrastructure projects these days.

  • If a power source goes offline, wouldn't you see a slump in voltage? Why the decrease in frequency?

    • by guruevi ( 827432 )

      You probably see both but frequency dips first. If one generator goes offline in a group of generators, the others get more "demand', in order to keep up the same voltage, with more current draw they are slowed down similar to how putting more load on a gas engine will slow it's RPM down.

      If they can't keep up, you would see a dip in voltage as well (a brown out) however it seems the battery packs kicked in before the generators dropped voltage.

      • ...with more current draw they are slowed down similar to how putting more load on a gas engine will slow it's RPM down.

        That is literally what is happening. The engines at the power plants are slowing down due to the additional load.

        Just like a Tesla car, the battery can go from no load to full load in milliseconds, where a mechanical engine takes significantly longer.

      • Most of the generators are of the asynchronous type (or induction type). This type or generatior produces no energy when the rotor runs at exactly the grid frequency. Not until the rotor of the generator spins faster than the grid, it produces energy to the net.

        The difference between the rotor frequency and the net frequency is called slip, and is usually a few percent. For typical slips, the produced power is proportional to the slip.

        So, if the load increases (or the generating power decreases), the (aver

    • Re:A slump in what? (Score:5, Informative)

      by HornWumpus ( 783565 ) on Tuesday December 19, 2017 @03:31PM (#55770663)

      They are both affected. But power companies will let the voltage drop while holding frequency as close to theoretical as they can. They even run 0.1 Hz high or low at the end of the day to get the correct number of cycles for the period.

      If you've ever designed a power supply, you'd see that you must accept low/high voltages, but should expect the frequency to be fairly steady.

      • If you've ever designed a power supply, you'd see that you must accept low/high voltages, but should expect the frequency to be fairly steady.

        Most power supplies I've seen, and made, will accept anything from below 50 to above 60Hz. The frequency is pretty much irrelevant as long as the transformer (for a linear) is still efficient enough. Now that most of them are switchers, they'll even take anything from about 90 through 240V, and some of them are quite happy running off of DC.

        • What were the specs for expected input power you got? Switchers don't care, but you started the design process with a power spec, the same spec every other power supply was designed against.

      • by torkus ( 1133985 )

        If you've ever designed a power supply, you'd see that you must accept low/high voltages, but should expect the frequency to be fairly steady.

        While I do expect it to be fairly steady, any experience I've had with power supplies doesn't have any major influence from frequency, especially within a few Hz.

        Where it's critical is for things like induction motors and transformers

    • by ColaMan ( 37550 )

      Grid voltage is generally maintained easily enough by the other power sources.

      But the frequency drops due to the other spinning generators being under heavier load and slowing down. As you drop the frequency, AC synchronous motors (fans, refrigerators, older/larger A/C units, etc etc) also slow down and use less power. So there's a balance point where the 600MW loss is offset by the drop in grid frequency.

      If you had a system comprised entirely of non-spinning sources of power (eg Tesla's battery, or flow ba

    • Re:A slump in what? (Score:5, Interesting)

      by Thelasko ( 1196535 ) on Tuesday December 19, 2017 @03:37PM (#55770711) Journal

      If a power source goes offline, wouldn't you see a slump in voltage? Why the decrease in frequency?

      In DC, yes. AC is a different animal. The AC frequency is determined by the speed of the generators. When demand outstrips the supply, the generators slow down. Therefore, the frequency drops.

      You would likely see a drop in voltage too. However, AC voltage is difficult to measure. Frequency is a much more precise way to measure the status of the grid.

      • by Orne ( 144925 )

        Most generators also have a voltage regulator, which changes the excitation / power angle. The generator produces MVA, which in polar notation is real (MW) and reactive (MVAR) power. Most generators try to operate near unity (MW/MVA = 1) to maximize income, but the controllers at each power plant probably twitched a bit to supply reactive power to keep the voltage levels stable.

    • Re:A slump in what? (Score:5, Informative)

      by RobinH ( 124750 ) on Tuesday December 19, 2017 @03:40PM (#55770743) Homepage
      Good question. A simple way to view it is that the grid is powered by generators. The generators are built to run at a fixed speed, and are wound so that the fixed speed outputs (in this case) 50Hz at a fixed voltage. The voltage output of the generator is a sine wave and it will lead (since it's generating) the grid voltage by a small amount (lead means same frequency, slightly ahead of phase). The amount it leads determines the load, and the generator has a limit to how much load it can handle, so if you tried to speed it up by turning it faster, it would start to lead slightly more and the load would increase (more current, but more resistance to the prime mover turning the generator) so the speed stays close to 50 Hz and it only speeds up a very small amount very briefly. When you drop a bunch of generation offline, the rest of the generators see a bunch more load suddenly, which is felt as a physical torque, so the generator gets harder to turn. The prime movers (turbines typically) can't produce more power instantaneously so the generators start to decelerate slightly. That's why you see the grid frequency drop slightly until the turbines increase power to take up the load. That's assuming the remaining generation can handle it. What they're saying here is that the Tesla system, since it uses inverters, can respond faster than the turbines generating power (duh). I'm not sure why it's described as shocking. Near where I live, in Canada, they installed a few MW of magnetic bearing sealed-vacuum flywheel energy storage specifically for frequency regulation due to all the new windmills they installed. The flywheels are spinning at synchronous speed and can absorb and deliver energy to the grid as needed, similar to the Tesla battery system.
      • by RobinH ( 124750 )
        I guess to be more complete, I should also add that when generation drops offline, but load is the same, then grid voltage *will* drop in the system, but the amount it drops is complicated. Every point in the system has a different voltage. The voltage drop causes more current to flow from the remaining generators, which is load, which causes them to slow down, hence the frequency drops a bit. The frequency drop is directly related to generator speed, and the generators are speed regulated so the control
    • The other responses explain part of the issue, but a critical problem is that when one plant slows down, they all have to slow down to avoid creating a significant phase difference. You can only tolerate the tiniest of tiny out-of-phase generation between any two plants, or you end up really blowing something up.

      • It's very difficult for one generator to go out of phase with the others. It's more likely the other generators will turn the failed generator into a motor to keep it in phase.
      • To really fuck things up, shutdown one phase while you leave the other 2 running. That's how you get bent generator shafts.

    • by dj245 ( 732906 )

      If a power source goes offline, wouldn't you see a slump in voltage? Why the decrease in frequency?

      Large generators are voltage controlled by the Automatic Voltage Regulator, or AVR. [srmuniv.ac.in] To simplify a complicated system, the rotor in large generators does not contain permanent magnets, but is instead an electromagnet. When output voltage drops, the AVR increases the current to the rotor coils. This keeps the voltage constant.

      The frequency is a function of how hard the generators are pushing the grid, and how hard the grid pushes back. Again, the AVR at each power station has controls which attempt to p

    • by AK Marc ( 707885 )
      If you are talking a battery-powered device, like a home UPS or the Tesla power station that this relates to, yes. You'd lose voltage, but not frequency.

      With coal generators, they are big spinners locked to the frequency of the grid. If you draw more power, you increase the load on the generator, and they slow down. But the voltage isn't as greatly effected. If the grid every went 100% DC, then you'd see the effect as a drop of voltage. As there is no frequency, and probably no spinners in regular use,
  • We had some fridge sized batteries to keep things up until the diesel generator kicked in. Two different jobs, fast response vs.prolonged heavy usage.
  • The coal plant that failed was producing close to 600MW. The max output from the graph in the article showed the battery system inject less than 10MW max into the grid. Who pickup up the other 500+ MW? The other coal plant that came online within 6 secs. Basically all the batteries did was reduce the size of the brownout.

    • by HornWumpus ( 783565 ) on Tuesday December 19, 2017 @03:39PM (#55770725)

      The grid worked as designed. News at 11.

      Steam plants don't come online in 6 seconds, they just don't.

      First the UPSs, then load curtailment, hydro and combustion turbines, finally the steam plants and steam parts of combined cycle plants.

      The real point (beyond the usual /. 'Ol Musky' blowing) is that apparently Australia was in spinning reserve violation when this happened. Your supposed to have enough power spinning to cover you single biggest unit/transmission line falling over (as they say in Australia).

    • Your right, it didn't stop an outage. The newsworthy part is how rapidly it responded.

      Even with a battery 5 times larger, it could only keep running for a finite amount of time. Another generator would eventually need to be added to the system.
    • by dj245 ( 732906 ) on Tuesday December 19, 2017 @04:11PM (#55771019) Homepage

      The coal plant that failed was producing close to 600MW. The max output from the graph in the article showed the battery system inject less than 10MW max into the grid. Who pickup up the other 500+ MW? The other coal plant that came online within 6 secs. Basically all the batteries did was reduce the size of the brownout.

      The "spinning reserve" generally picks up the demand. "Spinning reserve" consists of machines which are on the grid but not at full load. The spinning reserve should be a minimum of the sum of the largest individual generator + the maximum estimated demand change that could happen in around 10 minutes (the time it takes for a gas turbine to start up). Generally, all that is necessary to change spinning reserve into real power is for a valve to be opened further. For combustion or steam turbines, this can occur in less than a second, and is automatically controlled by the generator controller - the generator demand signal will increase as grid frequency decreases. Spread across many generators, the increase in output is not a significant shock to any individual generator.

      In this case, it seems that the Australian grid did not have adequate spinning reserve, which is why the frequency dropped. Many power stations are set to shut down in the case of large frequency variations (for machine protection), which caused the coal power station to shut down.

    • Came on line? I assure you the backup was ALREADY on line, steam in the boiler with the generator turning in sync with the mains.

      What it wasn't doing is pushing out power. Somebody or something has to advance the throttle to make that happen and apparently that takes about 6 seconds.

  • UPS, that's not a UPS,
    THIS is a UPS!

    hehe

  • it was expected to time shift a small amount of wind energy and provide network services and emergency back-up in case of a major problem.

    They had a major problem, and it did what it was supposed to do. How and why does this stun people?

    • Because insiders know how rare it is for something to do what it's supposed to do?
      • by Nutria ( 679911 )

        Electronics and electrical systems are supposed to be Solved Problems that Just Work when certified electrical engineers design them properly.

        (Having said that... I was pretty stunned earlier this year, when, during a power outage, the UPSes in the DC actually kicked in and then the generators fired up. But that's only because twice before, they failed miserably.)

    • The other day I was stunned when my automobile effortlessly transported me to and from the grocery store with no significant expended effort on my part.

    • by mspohr ( 589790 )

      it was expected to time shift a small amount of wind energy and provide network services and emergency back-up in case of a major problem.

      They had a major problem, and it did what it was supposed to do. How and why does this stun people?

      Since this is new technology and Tesla, there were lots of naysayers who were predicting that it just wouldn't work.
      It's news that it worked as it was designed to. It stabilized the grid. It was designed to stabilize the grid.

  • What? Who? How? (Score:4, Insightful)

    by Ancient_Hacker ( 751168 ) on Tuesday December 19, 2017 @04:02PM (#55770937)

    The narrative and conclusions are a big dodgy. Everybody knew beforehand that batteries can jump in immediately to supply power. And the batteries did not stop a complete collapse, electrical networks are thoroughly analyzed and simulated and braced against major consequences if any one unit trips out. Major outages are quite rare over the decades, and all done without a single battery. Gas turbines can come on-line within 60 seconds and other interconnected plants often have enough reserve capacity to tide over small outages. Batteries are welcome as an immediate source, but they are still awfully expensive and awfully small in GWH.

  • Outsmarts Lumbering Coal Units???? Tell me what you really think there. Geez. BIAS.

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