[carlos_rpn]

I didn't have time to read the whole thing so I don't know if they mention it, but another article about about using sand as heat storage pointed out one of the advantages is that the material isn't toxic, unlike chemical batteries.

[pbhjpbhj]

There were reports last year, IIRC, of "sand shortages". Presumably a logistics infrastructure problem that could be relatively easily overcome?

[coryrc]

That's of "sharp sand".

Sand batteries don't need sharp sand.

[carlos_rpn]

I remember those reports.

I wonder if it has to be the same kind of sand, or could be some that we neither have another use for, nor would damage any ecosystem (too much).