Technology readiness level and round trip efficiency of large-scale advanced compressed air energy storage

The British Royal Society has recently recognized that achieving net zero emissions requires a substantial amount of energy storage in the United Kingdom by 2050, totaling about 200 TWh, to address the intermittent nature of wind and solar energy production, spanning from seconds to seasonal variations. While their assessment acknowledges that hydrogen should play a predominant role in this storage, it also highlights exceptionally high technology readiness level (TRL) and round-trip efficiency that is attributed to large-scale advanced compressed air energy storage (ACAES), which is viewed as a formidable contender. However, in this discussion, we argue that these values may be somewhat exaggerated. While ACAES certainly offers potential advantages, it also confronts a multitude of challenges, particularly when it comes to extensive, large-scale implementation.