[icehawk]

Its fine as long as the amount of time it can provide rated output is longer than it time it takes to bring replacement generation capacity on line.

I don't care how long my UPS will actually last as long the holdover time is long enough to cover the time it takes to deal with all of the foreseeable problems in starting up the backup generator.

[ssl-3]

I don't think that grid-scale batteries are working with consumers on the grid in the same way that your home UPS is with you in your house.

Perhaps most-obviously: Consumers who are suddenly running on grid-scale batteries have no idea that this is a thing that is happening. There's no signal for them to shut their stuff off -- automated, or not.

It's a whole different paradigm than your UPS under your desk is: With your UPS, your system(s) receive a signal that things are running on local battery, and you've elected to configure things to use that signal to order an automated shutdown.

But, again: That doesn't happen with the grid-scale batteries under discussion -- at all. You're comparing apples to dildos here.

(Which is not to say that grid-scale batteries offer new opportunities for power cuts, because the opposite of that is true. It is instead just to say that unknowingly using grid-scale batteries is nothing like monitoring a local UPS is.)

[icehawk]

> It's a whole different paradigm than your UPS under your desk is: With your UPS, your system(s) receive a signal that things are running on local battery, and you've elected to configure things to use that signal to order an automated shutdown.

The setup you described there wasn't the situation I was describing at all.

I was describing a situation where there is utility power, a UPS, and a standby generator. When the utility power goes out, the generator has to start, stabilize, and only then can the load be transferred off the battery.

The requirement is that the UPS meet this current power demand for longer than the generator start up and transfer time (the "holdover time" I was speaking about in the previous post.)

For things like frequency response the holdover time is a fixed requirement. ERCOT requires all energy storage resources be able to maintain output for 15 minutes.