Investigation on the Influences of Interlayer Contents on Stability and Usability of Energy Storage Caverns in Bedded Rock Salt

Abstract to balance the intermittent of renewable power, large-scale energy storage in underground salt caverns can be utilized. And the construction and safety evaluations for these caverns become necessary. Aimed at the bedded salt rocks for energy storage, this study focuses on the effect of different interlayer content on the stability and usability of the underground energy storage caverns in bedded salt of China. Salt caverns with five different interlayer content of 0–30% are established for stability and usability comparison. The numerical simulations show that the caverns with high interlayer content have better stability performance than that of the cavern with lower or no interlayer content. A usability evaluation is also discussed by evaluating the effective volume of caverns with different interlayer content. Even though the caverns with high interlayer contents have less volume shrinkage, they have smaller available volume because the collapsed sediments of the interlayer expanded in the cavern bottom. Finally, a method to increase the effective cavern volume is discussed. That is to enlarge the bottom cavern in caverns with high interlayer content.