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Using Flywheels to Meet Peak Power Grid Demands 325

hackertourist writes "A novel type of electricity storage was recently added to the New York power grid. The unit, supplied by Beacon Power, uses flywheels to store energy. This system is intended to replace gas turbines in supplying short-term peaks in power demand (also known as frequency regulation). It can supply up to 20 MW, using 200 flywheels." If you can't afford a 200-flywheel system, you can always get a racetrack-ready Porsche 911 GT3 R Hybrid, which has a single energy-storage flywheel that can give you a 160 HP burst of power when you need a little extra oomph.
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Using Flywheels to Meet Peak Power Grid Demands

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  • by Mabbo ( 1337229 ) on Wednesday June 01, 2011 @12:35PM (#36309418)
    My grandfather was a manager with the utilities department for the city of Oshawa, Ontario. He described using this exact technology 60 years ago- a giant wheel maintaining momentum to keep the output predictable despite unpredictable input. Mind you, I don't think he was working on the 20MW range...
    • So, a mechanical capacitor?
    • Re:New tech? (Score:5, Insightful)

      by ottothecow ( 600101 ) on Wednesday June 01, 2011 @12:49PM (#36309554) Homepage
      Flywheels aren't new at all...but there was a lot of NIMBY paranoia about flywheels breaking loose and roaming the countryside. I can see how a giant steel cylinder rolling around with a ton of stored energy might be bad, but fail to see how that would occur when mounted underground in concrete with a vertical axis.

      In the case of these things, there seem to be many small ones (less risk if one "escapes") and something tells me that carbon fiber disks that are carefully stabilized and levitated in a vacuum while spinning incredibly fast...would break into a thousand pieces the second they left containment rather than rolling down the street and through someone's house.

      • by kevinNCSU ( 1531307 ) on Wednesday June 01, 2011 @01:20PM (#36309924)

        ..but there was a lot of NIMBY paranoia about flywheels breaking loose and roaming the countryside.

        God, am I the only one who wants to live in a world where this actually happens and you see a bunch of ME's from the power plant with yellow hard hats on sprinting after it yelling "Shit-shit-shit-SHIT! -*crushes car* - SORRY! - shit-shit-shit-shit!"

        • Re:New tech? (Score:5, Interesting)

          by TheRaven64 ( 641858 ) on Wednesday June 01, 2011 @01:35PM (#36310144) Journal
          One of my physics teachers at school used to work in a power station for a bit. He showed us some pictures of a 'fuse' that they used. When I think of a fuse, I think of a small, thin, piece of wire. This was a large copper bar. He also had some pictures from when it blew - the entire bar was vaporised. When people talk about MWs and GWs, the numbers don't seem real. When you see lumps of copper being instantly turned to gas, you get a real feeling for the amount of power involved.
          • It is indeed a different world. I come from a totally different field, but I am working with a couple of electrical engineers these days. When we had a talk about power supply systems, one of them made a comment that really opened up my eyes on how stuff works - "When you talk AC power lines - don't think about electrons moving around in wires. The energy is in the field. The wires are not for moving electrons, they are just guidance structures to direct the fields where we want them to go."
      • Re:New tech? (Score:4, Interesting)

        by goodmanj ( 234846 ) on Wednesday June 01, 2011 @01:41PM (#36310214)

        My worry isn't rolling stones, it's shrapnel. Beacon Power's flywheels store 25 kwh of electrical energy. If the rotor fails, this energy will be released in a fraction of a second, causing an explosion with the same energy as 20 kg of TNT. But TNT releases most of its energy in the form of heat, which is imperfectly converted to kinetic energy, while the flywheels will release pure kinetic energy. And it's kinetic energy that kills people. You'd better hope the engineer who designed the metal casing for the flywheel knew what he was doing!

      • Re:New tech? (Score:4, Interesting)

        by Gibbs-Duhem ( 1058152 ) on Wednesday June 01, 2011 @02:27PM (#36310840)

        If memory serves, the giant flywheel that MIT uses to spark their fusion test reactor is rigged with explosive charges to blow it to pieces if it ever came loose. I believe the calculations show that without detonating it, it would likely continue *through* several buildings before landing in the Charles River... could have been an urban legend though.

    • Re:New tech? (Score:5, Informative)

      by ron_ivi ( 607351 ) <.moc.secivedxelpmocpaehc. .ta. .ontods.> on Wednesday June 01, 2011 @12:52PM (#36309588)

      Also in use in vehicles since the 50's. []

      Rather than carrying an internal combustion engine or batteries, or connecting to overhead powerlines, a gyrobus carries a large flywheel that is spun at up to 3,000 RPM by a "squirrel cage" motor. .... ...
      Fully charged, a gyrobus could typically travel as far as 6km on a level route at speeds of up to 50 to 60 km/h, ...
      Charging a flywheel took between 30 seconds and 3 minutes;

      Sounds nicer than most electric cars.

      • by Nadaka ( 224565 )

        Ranges on EV these days are 30 to 300 km rather than 6.

      • Yeah, I think I'll take a Lithium ion battery in my trunk before I take a 3 ton hunk of steel spinning at 900km/h. That's a lot of energy, and unlike a battery, that energy has to go somewhere if it breaks.

    • That's very different. For instance one way that power fluctuations can be handled in an extremely complete manner is to use a motor-flywheel-generator set in direct connection as a power filter, with attendant losses in efficiency that you can imagine. IIRC at least one chip fab is/was protected in this fashion. This is about using flywheels like batteries.

    • Re: (Score:3, Interesting)

      by plut4rch ( 1553209 )
      The JET tokamak has had a couple of huge flywheels to provide the power to its field coils since the early 1980s, and those are around 400MW peak output. True the pulse only lasts around half a minute or so, but it's still very impressive. Each flywheel has a moment of intertia of something around 14 million kgm^2. This may not even be that relevant to TFA but I thought it might be interesting.
  • I've always thought a flywheel like this at the base of each windmill would be an awesome way to level out wind power fluctuations.

    • Re: (Score:2, Informative)

      by Anonymous Coward

      This is already standard practice. In fact, the entire fucking propeller acts a big flywheel. They are massive and balanced radially.

    • by SETIGuy ( 33768 ) *
      See my post above. Windmills used to be used in hybrid (wind+gasoline generation, flywheel+gravity storage) designs, back before we all had electricity at home.
  • "A novel type of electricity storage was recently added to the New York power grid ..." Flywheels as primary energy storage devices have been in even the popular literature for several decades []
    • by LWATCDR ( 28044 )

      They where also used as a suppressor and UPS on mainframes. Some mainframes uses a big electric motor to turn a flywheel that was hooked to a generator to act as a voltage regulator. Very effective for brown outs and spikes. And yea I remember reading about them in PopSci in the 70s right down to the magnetic bearings, carbon fiber, and vacuum chamber. Also some pretty spectacular pictures of failures as well.

    • Just a quick Note: You only need the id=___ and pg=___ (book Id & page number) parameters to link to Google books (usually just everything before the second & character. []

      Also you can make a link like this [] by doing this:
      <a href=""> this </a>

      • i got in trouble here the last time when i used google's URL shortener so i just thought wtf... but your tips are much appreciated, thankee
  • 20 megawatts peak output? But how many megawatt hours?

    • 5, because they only produce peak output for about 15 minutes.
      • ... the system can buffer $500 worth of power (5 MWh = 5000 KWh, $0.10/KWh wholesale).

        And it cost $40 million to build (at least that's the size of the loan)? That's 40,000 times the value of the energy it can hold.

        If the buffering keeps an expensive peaking source off-line, it might pay for itself in a few years of continuous use.

    • the article mentions ... 1 megawatt for as much as 15 minutes ... this is for each flywheel.

  • Gimbals (Score:4, Interesting)

    by TomorrowPlusX ( 571956 ) on Wednesday June 01, 2011 @12:42PM (#36309490)

    Dumb question, I suppose. But, given that the earth rotates, and given that the flywheels will have a huge angular momentum, are they gimbaled? The article says they're suspended in a vacuum, levitated on a magnetic field, which is cool. But if they're not gimbaled a huge amount of energy will be wasted fighting precession as the earth rotates.

    I assume the people making these things are smart and know their shit. I'm just curious how a problem like this is solved. If not gimbals, what?

    • by Dunbal ( 464142 ) *
      Superconductors, flux pinning, etc.
    • Oy Vey! - you orient the spin axis along true North.


    • by bobbuck ( 675253 )
      If that was a factor, wouldn't they just mount them parallel to the earth's axis?
      • by blair1q ( 305137 )

        Nope. Then gravity torque gives you a mess.

        They probably didn't mount them perfectly vertically. They probably also dynamically balanced them.

    • But if they're not gimbaled a huge amount of energy will be wasted fighting precession as the earth rotates.

      What means this "fighting precession?". As the axis of rotation changes there will be a torque on the axle -- big deal, this simply exchanges angular momentum with the earth. You just need an axle which can withstand that torque, and it ain't much torque.

    • Re:Gimbals (Score:4, Interesting)

      by SETIGuy ( 33768 ) * on Wednesday June 01, 2011 @01:37PM (#36310166) Homepage

      But if they're not gimbaled a huge amount of energy will be wasted fighting precession as the earth rotates.

      You don't need to gimbal them. If oriented correctly you can draw energy from the rotation of the earth to fight the precession effects. Basically nearly all of the force that keeps the axis aligned is transmitted through the mounting, and only tiny amounts will be derived from the rotation. Induced currents will be a more significant source of losses.

  • by macraig ( 621737 ) <[moc.liamg] [ta] [giarc.a.kram]> on Wednesday June 01, 2011 @12:43PM (#36309496)

    Does an obese cat in a giant hamster wheel count as a flywheel? No? What if I just hooked up a DC generator to it and dangled some liver on a stick? How many Watts could I get?

    • Does an obese cat in a giant hamster wheel count as a flywheel? No? What if I just hooked up a DC generator to it and dangled some liver on a stick? How many Watts could I get?

      In my experience, 2.21 jigga-watts (depending on the viciousness of the large dog behind the cat).

      After reaching an angular velocity of 88mph, you can send the device back in time to double your energy output -- The process yields unlimited Infinite energy (well, except for the limits of the world's production of meow-mix and cat-litter).

    • by vlm ( 69642 )

      Does an obese cat in a giant hamster wheel count as a flywheel? No? What if I just hooked up a DC generator to it and dangled some liver on a stick? How many Watts could I get?

      One horsepower is about the average sustained power output of a horse (imagine that!). There are always substantial energy conversion losses, and a fat cat is non-optimal compared to a born and bred working horse, so I feel comfortable saying you'll get about 500 watts per horsepower.

      Long term power output probably scales as weight, short term probably as surface area. A fat cat probably weighs more than 10 pounds and a hard core work horse probably weighs more than 1000 pounds. So I feel confident that

  • What's the cost? (Score:5, Interesting)

    by jamesl ( 106902 ) on Wednesday June 01, 2011 @12:44PM (#36309508)

    Why don't these alternative energy/power storage articles ever include cost comparisons? What do these flywheels cost to buy and operate compared to what they're replacing?

    • by drinkypoo ( 153816 ) <> on Wednesday June 01, 2011 @01:03PM (#36309734) Homepage Journal

      They compete with batteries. They are more expensive than crappy dirty ones and cheaper than fancy relatively clean ones. They are made with steel containment vessels and contain a bunch of electromagnets which you and I know as being made of wire. You can check pricing of maglev bearings online. The flywheels are made of carbon fiber so that if they should for some reason contact the housing, which as I recall is about an inch thick steel unit, they shred themselves into cotton candy or confetti or something like that instead of releasing their energy explosively. The various materials they're made of means you can assume they have a fairly high energy cost of production. The units are small enough to be ganged in shipping containers.

      • No one uses batteries on this scale. They compete with hydroelectric storage, where water is pumped up a hill to fill a lake. The environmental impact of such a system is large within the area of the lake, but relatively well contained.
    • Well, these are energy storage units rather than energy generation units. The electricity is generated elsewhere by cheap baseload generators and these flywheel units store it until it's needed to makeup shortfall by peak load. This gives you enough time to spool up the slow-reacting baseload generators.

      What they're replacing is probably gas turbines, which are expensive to run but have a very short reaction time and are generally used to meet peak loads. And gas turbines are generation units, so you can'

    • Not quite TFA, but here's a report from KEMA [] (pdf).

    • I suspect it's because these are not 'power generation' devices. They are simply batteries.

      There will be infrastructure costs associated with building them but there is no 'fuel' or significant ongoing cost. At least no more so than a comparable power generation plant. So that washes in terms of cost.

      By using renewable sources, like solar or wind, there also is no 'fuel' involved at all. This allows that intermittent renewable source to provide power when the source isn't producing directly.
  • About a decade ago these guys had or at least were advertising a tiny version of this technology for use as a UPS. It was supposed to be cost-competitive with medium-size units. Unfortunately it turns out that there's more profit in solving the peak demand problem by absorbing base load at night and delivering it during peak demand periods. Since they use maglev bearings, [partially] evacuated chambers, and magnetic induction, the units themselves are not only very efficient but should also have excellent longevity. It looks to me like they are making the chambers out of fairly standard (if sizable) pipe components.

  • by haruchai ( 17472 ) on Wednesday June 01, 2011 @01:03PM (#36309730)

    Jeff Veltri of Temporal Power has a flywheel design he claims can deliver twice the power at half the cost of the Beacon designs. Ten of his prototypes will be used for smoothing wind turbine power production. But his design is based on permanent magnets so I wonder how that'll fare which the rising cost of rare earth minerals. []

    • But his design is based on permanent magnets so I wonder how that'll fare which the rising cost of rare earth minerals.

      It seems like if you are capable of controlling the entire design you can use pretty big magnets, so you can therefore use cheap ones.

  • Just in case anyone was wondering about the age [] of this "news", I found an article from 2010 but I'm sure there's older. Ahh the internet, endlessly recycling news until it becomes new again.
  • Hoping the attention of the slashdot community will do good things for the Beacon stock I bought.
  • by 140Mandak262Jamuna ( 970587 ) on Wednesday June 01, 2011 @01:08PM (#36309798) Journal
    At present only industrial customers pay different rates for their electricity based on the time of day. Domestic electricity prices are constant all day. There is no incentive for anyone to defer their power consumption to off-peak hours, or to invest in any technology to smoothen out their power consumption curve. If we pay one price for the day time electricity and get a deep discount for the night time electricity, these fly wheel storage devices can be used to soak up energy at night and use it during the day. Since most of the day time power consumption is air conditioning, we could simply make ice/chill water at night and use it to cool the home during the day.
    • by h4rr4r ( 612664 ) on Wednesday June 01, 2011 @01:16PM (#36309868)

      Domestic electricity prices are constant all day.

      Maybe where you live, but not where I live. I bet if you requested the time based pricing you could get it. When I was growing up we only did laundry and dishes after 8pm. Cut the electric bill by a huge amount.

    • by Arlet ( 29997 )

      I don't know where you live, but we've had double meters (night and day) for as long as I can remember.

    • by Andy Dodd ( 701 )

      Wrong - many areas charge residents more during peak periods. California is especially known for this, and it's one of the reasons (lots of sun being the other) why residential solar power is fairly popular there. Peak solar generation times happen to coincide with peak electricity cost times.

    • by samkass ( 174571 )

      Heck, why artificially set prices at all? Someday everyone will be recharging their electric cars at night and companies will beg us to use electricity during the day instead.

      Now that meters are getting high-tech enough, we should just have a spot market for power and buy/sell into that market any time of the day or night.

  • Seriously why use stupid units in these stories. The system provides 15 mega watts for 15 minuits. Thats 3.75 Mw-h. according to the wikipedia an average person uses 11,400 W (average not peak).
    So this can power 40 people for 8 hours.
    Now you'll have to excuse me I have a meeting in 2.8 hogsheads. After that I have to goto the store and buy a meter of milk. And my furnace is a 15000BTU model and it's used them all up.

    • Sure, not mentioning its storage capacity is an omission, but quoting the maximum power output is hardly irrelevant or stupid.

    • by Arlet ( 29997 ) on Wednesday June 01, 2011 @01:42PM (#36310240)

      That average energy consumption isn't just electricity. Average electricity per person is just 1460 W for the US, which is what this system is for.

    • by blair1q ( 305137 )

      You've got a 3-gill head in a 10-bludger hat.

      This thing isn't meant to supplant the entire supply in case of a blackout. It's meant to give the grid a few MW for a few minutes to prevent a brownout that could cause a blackout.

      And it's probably not meant for a major portion of the grid, just a locale with an incipient supply problem.

    • Because it's being used as a temporary generator, not a battery.
  • Liebert [] made one of these for server room UPSs. We never got one although the salesman tried to get us to buy it. The thought of that wheel sitting in the next room and spinning that fast spooked me. I am not religious but there is no need to constantly tempt fate by working next to that kind of energy day in and day out. I guess it is a good way to store energy but I really dont want one in my backyard, basement or server room. Let's see the explanation for that disaster. Well, we made it through the

"I will make no bargains with terrorist hardware." -- Peter da Silva