It's not that much energy anyway. 1kwh is about 3.6 megajoule. 2200 times 9 divided by 3.6 is about 5.5mwh. This is obviously not intended as a battery but more

It's not that much energy anyway. 1kwh is about 3.6 megajoule. 2200 times 9 divided by 3.6 is about 5.5mwh. This is obviously not intended as a battery but more as a very low latency control mechanism to control frequencies and voltages. You'd only be able to use it for very short bursts of energy probably in the order of a few seconds or minutes. You'd use something like this while bringing online alternative sources of energy, which takes time. Of course a grid battery probably wouldn't need this as it would be similarly quick to come online. Which raises the question why they are going for synchronous condensers instead of grid battery. One doesn't exclude the other of course.