4 ms·

Boy, flywheel batteries. At the Ford Museum (in Ann Arbor I think?) they have some of the earliest versions of these, for steam generators I believe. Maybe 30 f

Boy, flywheel batteries. At the Ford Museum (in Ann Arbor I think?) they have some of the earliest versions of these, for steam generators I believe. Maybe 30 feet in diameter, must weigh a couple tons at least? The idea of one spinning even at 20 or 30 RPM was a scary demonstration of potential energy. If it got loose it seemed like it would blast through the wall and roll halfway across the country. But they were beautiful, well made, and instructive. That said, it's an interesting way to store energy and I hope it can be deployed safely and beneficially.

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WilliamSt 8y ago
The spinning wheel has kinetic energy, not potential energy, right?
- bonzini 8y ago
  It's kinetic energy if you consider rotation around the center of the flywheel (I * omega^2/2), but only potential energy to move around and destroy stuff (m * v^2/2). If you let the flywheel loose, it becomes just a wheel and it's not potential energy anymore. :-)
- ars 8y ago
  > potential energy There isn't really such a thing. It's just a matter of your viewpoint if something is potential energy or actual energy. Physically they work the same (for example both types of energy gravitate, and contribute to mass).
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masklinn 8y ago
> The idea of one spinning even at 20 or 30 RPM was a scary demonstration of potential energy. Grid FES rotate at above 10k RPM. Munich has a control & stabilisation FES whose flywheels max out at 45000 RPM. Though they're probably not 60 feet wide the 28 flywheels store up to 100kWh.
seanalltogether 8y ago
Yeah if they're using flywheels, I hope they're planning on putting them in the ground, under a thick block of concrete, far enough away from where people will be charging.
Theodores 8y ago
...so that was where Williams F1 got their idea from! The last 'failed flywheel' project that I know of is the Williams F1 solutions for 'KERS' - kinetic energy something system... This system lost out to normal batteries in F1 and Williams sold on their flywheel business to GKN. GKN now sell the Williams flywheel solution for things like buses. For a while Porsche 911 style cars (RS-whatever) had the Williams flywheel, this took up the passenger seat so you could be sat next to one of the things in your roll cage, with helmet and flameproof suit on. That project died a death. Before anything was known of the Williams system I was 'hoping' it would be entirely mechanical, no electrons needed. However, their solution was electric so the motor driving the wheels could go in re-gen mode and another motor/generator in the flywheel pack spun the flywheel up to speed. The Williams system never exploded and there were no safety concerns, which is of note as F1 (thanks to Jackie Stewart) is extremely safety aware.
- rurban 8y ago
  The problem was less technical, more psychological. Nobody wanted to sit near such a 140K rpm thing, with a razor sharp crazy sound. Worse then nuclear, which you don't hear at all.
orbital-decay 8y ago
That probably was a solid wheel, right? Modern flywheels are usually made of carbon or glass fiber and have much simpler failure modes. They just break if anything goes wrong, not rolling anywhere.
- Johnny555 8y ago
  They just break if anything goes wrong Where break means explode, hopefully contained by the housing.
  - orbital-decay 8y ago
    Yeah, a high velocity chunk of fiber can be pretty nasty too. Still, it's much easier to contain compared to a huge metal wheel, because they literally disintegrate on failure when saturated.
    - carapace 8y ago
      Goes right to turbulent flow, as opposed to the laminar flow of metal in/as the wheel. Nice.
    - e12e 8y ago
      Technically gas is "soft" but doesn't seem that way when powder explodes. It doesn't seem trivial to contain this energy - the vessel would still explode, given enough energy in the wheel? Certainly safer than launching a giant death Frisbee... But lots of energy is still lots of energy. I guess it's a bit machine gun bullet vs hand grenade - about equal energy - but the grenade will just blow up a room while the bullet will go through walls and lodge in an engine block.
    - ams6110 8y ago
      It's the sudden release of energy that matters. Not the composition of the flywheel.
- ars 8y ago
  > They just break if anything goes wrong, not rolling anywhere. I saw a video of a flywheel being deliberately destruction tested. "just break" is putting it mildly - it looked like an explosion, and left white-hot pieces of the flywheel behind.
e12e 8y ago
Recently had the opportunity to tour the Sima powerplant [s]. They have an installation showing a broken turbine, somehow a stone got in that was big enough to jam up the turbine, leading to the single-cast steel contraption bending and ripping. Thankfully they managed to cut off the water before catastrophic damage occurred (to the installation/people). The explanation is all the more mesmerising for being held next to two such beasts going full tilt just under the floor. You can't see the damage in this picture (from a Google search), but you get a feel for the size (some of the "hands" were bent and broken before the emergency shut-off). The black shape in the back is one of the two operating turbines: https://cdn.discover-the-world.co.uk/images/education/norway/gallery/lightbox/norway-sima-power-plant.jpg https://cdn.discover-the-world.co.uk/images/education/norway... This one looks to be taken earlier, seems one of the pieces that were torn off is on the floor: https://media-cdn.tripadvisor.com/media/photo-s/08/61/60/b0/sima-power-plant.jpg https://media-cdn.tripadvisor.com/media/photo-s/08/61/60/b0/... Anyway, this isn't a flywheel - it's "just" a turbine. [s] https://en.m.wikipedia.org/wiki/Sima_Hydroelectric_Power_Station https://en.m.wikipedia.org/wiki/Sima_Hydroelectric_Power_Sta...
- geezerjay 8y ago
  > Anyway, this isn't a flywheel - it's "just" a turbine. More specifically, that's a Pelton wheel https://en.wikipedia.org/wiki/Pelton_wheel https://en.wikipedia.org/wiki/Pelton_wheel

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WilliamSt 8y ago

The spinning wheel has kinetic energy, not potential energy, right?

bonzini 8y ago
It's kinetic energy if you consider rotation around the center of the flywheel (I * omega^2/2), but only potential energy to move around and destroy stuff (m * v^2/2). If you let the flywheel loose, it becomes just a wheel and it's not potential energy anymore. :-)
ars 8y ago
> potential energy There isn't really such a thing. It's just a matter of your viewpoint if something is potential energy or actual energy. Physically they work the same (for example both types of energy gravitate, and contribute to mass).

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masklinn 8y ago

> The idea of one spinning even at 20 or 30 RPM was a scary demonstration of potential energy. Grid FES rotate at above 10k RPM. Munich has a control & stabilisation FES whose flywheels max out at 45000 RPM. Though they're probably not 60 feet wide the 28 flywheels store up to 100kWh.

seanalltogether 8y ago

Yeah if they're using flywheels, I hope they're planning on putting them in the ground, under a thick block of concrete, far enough away from where people will be charging.

Theodores 8y ago

...so that was where Williams F1 got their idea from! The last 'failed flywheel' project that I know of is the Williams F1 solutions for 'KERS' - kinetic energy something system... This system lost out to normal batteries in F1 and Williams sold on their flywheel business to GKN. GKN now sell the Williams flywheel solution for things like buses. For a while Porsche 911 style cars (RS-whatever) had the Williams flywheel, this took up the passenger seat so you could be sat next to one of the things in your roll cage, with helmet and flameproof suit on. That project died a death. Before anything was known of the Williams system I was 'hoping' it would be entirely mechanical, no electrons needed. However, their solution was electric so the motor driving the wheels could go in re-gen mode and another motor/generator in the flywheel pack spun the flywheel up to speed. The Williams system never exploded and there were no safety concerns, which is of note as F1 (thanks to Jackie Stewart) is extremely safety aware.

rurban 8y ago
The problem was less technical, more psychological. Nobody wanted to sit near such a 140K rpm thing, with a razor sharp crazy sound. Worse then nuclear, which you don't hear at all.

orbital-decay 8y ago

That probably was a solid wheel, right? Modern flywheels are usually made of carbon or glass fiber and have much simpler failure modes. They just break if anything goes wrong, not rolling anywhere.

Johnny555 8y ago
They just break if anything goes wrong Where break means explode, hopefully contained by the housing.
- orbital-decay 8y ago
  Yeah, a high velocity chunk of fiber can be pretty nasty too. Still, it's much easier to contain compared to a huge metal wheel, because they literally disintegrate on failure when saturated.
  - carapace 8y ago
    Goes right to turbulent flow, as opposed to the laminar flow of metal in/as the wheel. Nice.
  - e12e 8y ago
    Technically gas is "soft" but doesn't seem that way when powder explodes. It doesn't seem trivial to contain this energy - the vessel would still explode, given enough energy in the wheel? Certainly safer than launching a giant death Frisbee... But lots of energy is still lots of energy. I guess it's a bit machine gun bullet vs hand grenade - about equal energy - but the grenade will just blow up a room while the bullet will go through walls and lodge in an engine block.
  - ams6110 8y ago
    It's the sudden release of energy that matters. Not the composition of the flywheel.
ars 8y ago
> They just break if anything goes wrong, not rolling anywhere. I saw a video of a flywheel being deliberately destruction tested. "just break" is putting it mildly - it looked like an explosion, and left white-hot pieces of the flywheel behind.

e12e 8y ago

Recently had the opportunity to tour the Sima powerplant [s]. They have an installation showing a broken turbine, somehow a stone got in that was big enough to jam up the turbine, leading to the single-cast steel contraption bending and ripping. Thankfully they managed to cut off the water before catastrophic damage occurred (to the installation/people). The explanation is all the more mesmerising for being held next to two such beasts going full tilt just under the floor. You can't see the damage in this picture (from a Google search), but you get a feel for the size (some of the "hands" were bent and broken before the emergency shut-off). The black shape in the back is one of the two operating turbines: https://cdn.discover-the-world.co.uk/images/education/norway/gallery/lightbox/norway-sima-power-plant.jpg https://cdn.discover-the-world.co.uk/images/education/norway... This one looks to be taken earlier, seems one of the pieces that were torn off is on the floor: https://media-cdn.tripadvisor.com/media/photo-s/08/61/60/b0/sima-power-plant.jpg https://media-cdn.tripadvisor.com/media/photo-s/08/61/60/b0/... Anyway, this isn't a flywheel - it's "just" a turbine. [s] https://en.m.wikipedia.org/wiki/Sima_Hydroelectric_Power_Station https://en.m.wikipedia.org/wiki/Sima_Hydroelectric_Power_Sta...

geezerjay 8y ago
> Anyway, this isn't a flywheel - it's "just" a turbine. More specifically, that's a Pelton wheel https://en.wikipedia.org/wiki/Pelton_wheel https://en.wikipedia.org/wiki/Pelton_wheel