This is already done. It’s a blunt system, but it is done.
I was offered $5/month off my electric bill to add a device to my AC unit that would be able to turn it off for up to 15 minutes per hour. (I declined, because my AC at that time was not able to keep up even running constantly.)
There is no advantage using Lithium batteries (at present) as size and/or weight is not critical for domestic applications.
The whole point of the discussion is that Lithium is still not cheaper than Lead acid.
If those weren't enough, even when treated well (not discharged too deeply) lead-acid batteries don't last for as many discharge cycles as lithium iron phosphate cells. If you do the math, for batteries cycled daily modern LiFePo batteries are about the same TCO as lead-acid despite the higher up-front costs because the lithium batteries will last significantly longer and you don't need to buy as much absolute capacity for the same effective capacity. Here's a good presentation on this: https://www.youtube.com/watch?v=BRqRDZh74F0
[1] http://omahamakergroup.org/2015/05/14/battery-derating-and-c...
[2] https://www.pveducation.org/pvcdrom/lead-acid-batteries/char...
[3] https://www.solar-electric.com/media/wysiwyg/cyclelife2.gif (Graph shows cycles (y-axis) vs average depth of discharge (x-axis) for a typical "deep cycle" lead-acid battery. Note the y-axis is logarithmic.)
My expectation is that with climate change, unreliable electricity is going to affect a lot more places. The polar vortex that knocked out the Texas grid is likely to be a more frequent and more extreme event. ACs running more frequently will likely lead to more brown outs.
Assuming our grids don't get major updates (I'm pretty pessimistic about this), we are looking at more and more outages in the future. It's certainly possible that smart grids could significantly reduce outages, but that will take too many actors working together to ever really fly.
For example, if the grid could coordinate with your heating and cooling, you could distribute AC usage to avoid tripping the grid.
Barring such a grid, homes having batteries would allow owners to skate through brown outs. Further couple that with solar and they could survive even major outages (hours or even days).
> The overlap isn’t zero, but… for example, I visited Kenya with an ex of mine, we met a local friend of hers, that friend would’ve benefited from a more reliable electricity bill, but her monthly rent and utility bills combined was equivalent to about $85 and she couldn’t afford to move.
A 1kwh battery would probably be a pretty positive impact. Add on a 300W solar panel and you'd have something that would extend the amount of electricity the have. That'd come in at ~$400 (assuming $50/kwh). Not enough to run an AC, but enough to keep the lights on and maybe run a fridge.
Otherwise... yeah... not much good news for places that can't afford such batteries.