[1] looking for the shorthand for the original link that started the discussion, thinking that 'TFA' is correct, is this in the HN FAQ?

It appears (not an expert) that Texas leads the country by such a margin in renewables that increasing battery storage an order of magnitude in 3 years was sort of a drop in the bucket.

Look at the revenue: it's 6% (now 12%) from energy arb and 58% (now 34%) from RRS-PFR (primary frequency response). Fully discharging and charging a battery is expensive from a lifecycle perspective (I think, I would love a reference), and if you can get paid a lot of money to charge/discharge by 5%, or not to do anything at all but sit charged (ECRS), you'd take that before damaging your expensive installation.

There isn't a lot of generation like this, primarily because getting a thermal generator to scale up or down is expensive, even for the nimblest of combined cycle plants.

Seems like this is 'really short term' (under 1h) and in the realm of frequency stabilization (short peaks)...?