Comment by jtr1

Sodium is an interesting chemistry, though it has different voltage curves than lithium ion once hardware is built to match it they may scale well for industrial use.

That still doesn't avoid the more fundamental math of having to store such massive amounts of energy though, even if you skip batteries and pump water to retention ponds uphill.

Even for small scale residential, the recommendation is to store 3 days worth of average usage to handle stretches of cloudy days and to have a generator for the times when that still doesn't cut it. You also need enough solar that 4-6 hours of generation can fill those batteries back up after a stretch of cloudy days.

You also have to contend with frequency issues. This is what took down Spain's grid, they had turned on a ton of solar at the time - with many gas plants offline a seemingly small dip below 60Hz really wrecks much of the system when it wasn't designed to handle those swings and triggers multiple safety mechanisms.