[pfdietz]

I disagree! It's a vital problem to solve, especially if solar becomes significantly cheaper than wind (as appears to be happening; solar has the better experience rate). And solving it punctures one of the last arguments bad-faith nuclear advocates use to argue against renewables.

I will once again point to Austin Vernon and Standard Thermal, which has an approach that could truly solve the problem. The first principles analysis of the issue shows the problem with "sand batteries" and the like.

https://www.orcasciences.com/articles/standard-thermal

"Given that heat capacities of solids are all generally similar at ~3kb per atom, we’d need to store heat in a solid that costs ~$10-30/ton or less and tolerates very high temps. But nothing built on a foundation or made in a factory is sold for less than $100/ton. There’s almost nothing that even gets shipped in the dollar per ton range."

https://www.austinvernon.site/blog/standardthermal.html

https://www.standardthermal.com/