This product utilizes innovative energy storage technologies. It improves the low energy storage efficiency(Round-Trip Efficiency, RTE) of 50~70% typically associated with conventional Compressed Air Energy Storage(CAES), and overcomes the geological constraints and the drawback of large space requirements for installation of Pumped Storage Hydropower (PSH). Furthermore, it leverages the advantage of CAES, which requires only about one-tenth the installation area compared to PSH, while achieving a high RTE of approximately 80%, comparable to the 86% efficiency of lithium-ion battery-based ESS (LiB). This enables the system to mitigate grid instability caused by renewable energy generation and store utility-scale over-generated power of over 1,000 MWh for extended duration more than 8 hours.