[why_only_15]

This isn't really how batteries make money in the US right now, as I understand it. ~80% of battery revenue in ERCOT comes from what are called "ancillary services" [0] which is payment from the grid for being able to very quickly increase or decrease the amount of generation to ensure stability.

[0]: https://cimview.com/monthly-battery-revenue-in-ercot/

[epistasis]

This revenue will quickly disappear, however, as there is limited need for ancillary services. Lithium batteries served this purpose well in PJM starting long ago (more than a decade?), even with very high battery prices of yesteryear.

New battery additions must be banking on limited ancillary services revenue. Unless Texas investors never bothered to learn the lessons of the storage experience in PJM, which seems unlikely to me.

[cwal37]

Those early reg-d PJM batteries also got absolutely physically wrecked, so it wasn’t the best outcome.

ERCOT is quite different from PJM when it comes to AS - the market is very deep and the operational needs are increasing in a way they aren’t in PJM (yet). Couple that with a vastly easier permitting regime and hugely faster interconnection process for a facility (batteries) that require relatively little land compared to conventional generators, and Texas has enabled ERCOT’s queue to become absolutely stuffed full of battery applications.

PJM was ahead of the ball on market design, but that was a (relatively) long time ago. Now they’re in the midst of their massive backlog queue transition and also revamping (for the nth time) facets of their capacity market.

[why_only_15]

Why did Texas not start building out batteries for ancillary services until recently? Did/do they not need as much ancillary services as PJM? Also -- do you know what happened to ancillary service pricing as batteries became cheaper? Did grids become much more stable in practice?

[epistasis]

Edit: cwal37 seems to be better clued into ERcOT's market https://news.ycombinator.com/item?id=39393321

That is beyond my knowledge; I know that PJM specifically set up a market for ancillary services that allowed battery operators to get paid. I assume ERCOT must have set up some sort of similar market, but I don't know the particulars...