Indeed; I'm not sure why exactly so few of the CAES plants have been built, it's well understood, has minimal safety problems, and doesn't seem unreasonably exp

Indeed; I'm not sure why exactly so few of the CAES plants have been built, it's well understood, has minimal safety problems, and doesn't seem unreasonably expensive. If I had to wager an uneducated guess, workable salt mines may not be located anywhere the power pricing makes sense for long term storage offsetting like that.