You don't want it to be like a balloon. You want the enclosure to remain a constant size so you compress the air maximally.
Also, if it stretched the ground, that would be bad, seismically speaking.
It is an equally valid concept to water batteries, which definitely work. Work well enough to keep the grid stable with highly variable input? Dunno, but they work.
Only problem with using the Mines around here would be plugging all the holes! That and some of the old mines in this area run underground for many miles and interconnect with others! At one time you could go underground and emerge 15 miles away!
would take a LOT of air to pressurize that mine system!
I don't think just any mine is a candidate, nor is using the entire volume of underground airspace in a region the plan for an operational design.
hmmm i was thinking more a balloon a large sealed chamber not so much the stretchy bit... more like maybe something from an underground nuke test... hey that may work... a glass coated underground chamber...bingo...
I wouldn't want to pull maintenance on the turbine that used air stored in a nuke made vault! I'll stick to using the light switch to see in the dark instead the glow off my body, thank you!
SoR_AWC
The air, pumped into large underground formations,
too bad there arent many rocky caverns analogous to a balloon.