“I’m having trouble processing in my mind the need or the feasibility of grid battery storage, at least for the purported reasons (i.e. powering the grid through the night for hours until the sun comes back up).”
It’s not that hard to understand. The choke point for solar power is in the evening when people are home, awake, and busy, but the sun is next to useless. Getting through that bump requires either new powerplants or batteries. An average home runs on about 1 kW excluding AC, Electric Heating, and Tesla Charging, so 8 kWh of battery is plenty and, these days, is small and relatively cheap (maybe $3k for batteries and associated hardware, plus labor).
The question then becomes - do you require, or even want, people who don’t know how to stop a smoke alarm from beeping to have 8 kWh and associated electronics in their homes, or do you put it all in large, battery farms. Well, ‘investors’ have decided to put it in battery farms.
By the way - do you know why they always seem to locate the battery farms in highly populated areas, when they could be in the middle of farms or deserts and do perfectly fine supporting the grid there? Question for our audience - let’s see if anyone gets it right.