Design of a novel hybrid advanced adiabatic compressed air and gravity energy storage system

To enhance the energy efficiency and energy density of physical energy storage (PES) systems, this study introduces a novel hybrid advanced adiabatic compressed air and gravity energy storage (HAACAGES) system. This system integrates advanced adiabatic compressed air energy storage (AA-CAES) and gravity energy storage (GES) components, utilizing the mass of the compressed air (denoted by Δ m ) to make the HAACAGES system overwhelm the capabilities of individual systems. A numerical analysis model was established to validate the proposed system. Results demonstrate the HAACAGES system outperforms the individual systems in terms of both energy efficiency and density. Specifically, the energy efficiency is always higher than the sum of the individual systems at altitudes from 0 to 3 km. At 3 km altitude, the energy density reaches nearly 1.5 times that of conventional AA-CAES systems. At 1 km altitude, it exceeds 10 times that of conventional GES systems. Overall, the HAACAGES system shows clear potential as a promising solution for the next generation of large-scale PES systems.