Utility-scale energy storage is a cornerstone of supporting ... For example, a solar power plant could help compress air into a salt mine around noon when the power to do so is abundant.

“They mined out over 980 acres of salt in this mine,” says Lee Spence, president and CEO of Underground Vaults and Storage, located Hutchinson, Kan. “On a daily basis, they produce right ...

But extracting the coveted salt means descending into dark caves, then blasting and carrying heavy rock. Faizan Panjwani: The problem is the massive size of the blocks that come from the mine.