[darksaints]

While I'm a pretty big fan of low tech solutions, I'd just like to point out that electrochemical hydrogen compressors can basically already do this, but better. 80% round trip compression efficiency, up to 700 bar compression, no moving parts, and massively long lifetimes (in the 30-50 year range). The fact that the compression medium (hydrogen) is also an energy storage medium is just a cherry on top. It's just a matter of price coming down for 700 bar pressure vessels.

[DoingIsLearning]

The advantage of a system as simple as compressed air, is that anyone with a minimal technical background and shop tools is able to maintain and minimally repair the compression system.

An electro-chemical hydrogen conversion and compression vessel would have far more points of failure with far greater technical barriers to repair. The access to specialized spares in a remote location would also be a major issue.

I am not saying it cannot become a player in energy storage to eliminate the need for coal and natural gas energy generation. But it seems unlikely that would be a good choice for remote 'off-grid' location.

[jacknews]

Indeed, compressed air seems ideal for hot humid climates (cool/dry air being a byproduct of discharge), which are are often quite low-tech.

[jacknews]

This is a very interesting technology, and can be used with other gases too: https://www.sciencedirect.com/science/article/abs/pii/S01407...