Those things have interesting failure modes. Will they have to be buried underground, or is this somehow a solved problem?
Illustrated here in a 1 MW Beacon power system:
https://invidio.us/watch?v=eCtlfj4kMJs
Not all vendor systems incorporate these features, e.g.:
The flywheel disintegrates and turns into a massive spherical weapon of mass distruction?
Like this, but 20x worse?
If it's a 100kw peak electrical machine then it can provide at most 100kw of instantaneous power to the grid while at the same time slowing down by however much is required to deliver that power.
If I understand correctly the idea is a lot like capacitors for DC voltage. The DC voltage has to go down in order for the capacitor to supply current, but the capacitor ensures that the voltage can't go down as quickly as it would otherwise.
Suddenly all that stored energy wants to go somewhere.
In a conventional plant, the spinning machinery is monitored by vibration sensors. If the vibration exceeds some threshold, a "Turbine Trip" occurs and the offending generator is disconnected from the grid. It then slowly spins down, dissipating energy via it's own friction.
That means it can spin at any frequency and it doesn't really matter what state the grid is in.
It's a synchronous rotor which is spun by the mains. When the mains frequency tries to change, the momentum of the flywheel supplies massive leading or lagging current to prevent the change.
It behaves exactly as an un-powered generator idling on the mains.
There is no DC motor.
In the industry they are known as a "Synchronous Condenser" or Syncom. They have been in use for a long time.
https://www.pv-magazine-australia.com/2019/04/06/long-read-b...
It's a synchronous motor which normally idles at the Mains frequency, but if the Mains frequency attempts to change, the rotor inputs massive amount of current (leading or lagging) into the mains which prevents the change.
There is no need for a drive motor.
In the industry they are known as a "Synchronous Condenser" or Syncom. They have been in use for a long time.
https://www.pv-magazine-australia.com/2019/04/06/long-read-b...
I guess I had assumed -- especially based on the picture and description -- that a portion of the mass of the device was the synchronous motor and that a portion of the mass of the device is just "dead weight" whose purpose is just to act as energy storage via rotational inertia.
The parallels to the steam turbine would seem apt; the turbine end of a generator has a lot of mass relative to the electrical end. Isn't that a part of the point? Or did I miss something?