Comment by cucumber3732842

>The main downside is power density, which for grid storage is not as big a deal

It matters less but it's still a big deal though. You need to inject the power near where you need it otherwise you have to upgrade everything between you and them, roughly speaking. So you can't put your battery in BFE where land is cheap.

Cost increases from that plus environmental and site development regs (which are always more in denser areas) screw you too. So between the upgrades and the overhead there might not be a valley of profitability because all the sites you could toss a battery on and the sites where someone who has a more $$ use case than you will outbid you on the raw land.

So the end result is you wind up having to shoehorn a bunch of little developments into small crappy parcels but then the fixed costs of development come back to bite you so density matters there because the more jiggling electrons you can pack in the more revenue you can have to offset your fixed costs.

That said, anything that lets you tell the NFPA, the environmentalists and the local screeching Karens to take their setbacks and shove them hugely improves density, especially on small sites, so the reduction in cooling needs and runaway protection that sodium gets you might make it denser once the tech is fully vetted. Every foot you can shave off the effective footprint of a battery (after accounting for fire setbacks, service space, etc) hugely increases the number of sites that are developable.