We are not talking about the energy balance, we are talking about grid strength/inertia also known as ancillary services. Two orthogonal concepts people tend to mix up.

The article mentions the critical parameters which historically have been sourced from big heavy generators like hydro, coal, nuclear or CCGT plants:

- Frequency regulation: When grid power crashes or surges, the device immediately releases or absorbs energy to minimize fluctuation in the AC frequency;

- Short circuit power: When the grid experiences a short circuit, the crashing voltage releases a tripling or more of current from rotating machines which signals breakers on the grid to activate and quickly isolate the fault;

- Voltage support: Producing current and voltage that are out of phase generates so-called reactive power that pushes the local grid’s voltage up or down to stabilize system voltage and/or increase the flow of real power.

Lucky that has nothing to do with how grid stability works then… We’re talking about frequency correction, reactive power control etc. here!

Yes?

This is about Inertia and frequency control. Not about bulk energy storage.