You may want to update your priors [1][2][3]
1. https://www.carbonbrief.org/guest-post-how-solar-panels-and-...
2. https://www.fastcompany.com/91500104/google-minnesota-data-c...
1. https://www.carbonbrief.org/guest-post-how-solar-panels-and-...
2. https://www.fastcompany.com/91500104/google-minnesota-data-c...
> The new plant in Minnesota will be big enough to deliver 300 megawatts of power and store an enormous 30 gigawatt-hours of energy, making it the largest battery by capacity that’s been announced so far. By comparison, that’s more storage than all of the battery projects built in the U.S. in 2024 added together.
If I'm doing the math right, Minnesota used 65.7 TWh of power last year so to store 3 days worth of power just for that one city we would need a battery 18x larger than the one mentioned here.
I can't imagine we could ever scale such storage capacity for all energy use, let alone all the wind and solar required to fill it.
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.
The "inertia" issues already have solutions being used in production (in Australia, for example).
The inertia problem you mention wasn't solved in Spain though, and whether it can be solved or already is elsewhere is irrelevant here.