Comment by slfnflctd

People have been experimenting with compressed gas energy storage for a long time. This one may finally have legs.

First thing I thought of was a startup from years ago, mildly surprised no one has mentioned it:

https://en.wikipedia.org/wiki/LightSail_Energy

I was really excited about them and was disappointed to see the project fail.

It seems using pure CO2 and scaling up to a massive size are significant boosts to this type of technology (in addition to the heat mitigation along the way).