[Johnythree]

A flywheel can provide frequency stabilisation, or it can provide energy storage, but it can't do both at the same time.

To provide frequency stabilisation is must be synchronised to the mains (eg run at a constant speed), while to provide storage it must be non-sychronised, eg slow down when loaded, and speed up when charging.

Of course you can use non-synchronous flywheels with synchronised inverters, but then you can do that with batteries, wind-generators, etc.

[hpb42]

> A flywheel can provide frequency stabilisation, or it can provide energy storage, but it can't do both at the same time.

Ah, that's a good point to know. I thought flywheels could to both at the same time. Do they also help with keeping the load resistive? I guess their high inertial mass would add some inductance, which is how they stabilize the frequency?

Do you have some resources about this topic to share to a layman like me?