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This paper presents the geological resource potential of the compressed air energy storage (CAES) technology worldwide by overlaying suitable geological formations, salt deposits and aquifers. For this study, the world is divided into 145 regions, which are aggregated to 9 major regions. The potential of CAES in each region is assessed and a relevant map is provided. Three constraints have been implemented, allowing for 1%, 5% and 10% of the selected area to be considered for CAES. Among all major regions, in the most conservative constraint (1% of the total area), North America is the leader with 0.26% suitability of its total area, followed by Sub-Saharan Africa and South America at 0.20% and 0.19%, respectively. A sensitivity analysis is implemented to evaluate the validity and reliability of the results. Three scenarios are considered: Optimistic, Moderate and Pessimistic. Underground natural gas storage data for the US is used due to freely and publicly available data. The natural gas storage site is assumed to have the same structure as CAES. The sensitivity analysis shows that the accuracy of the findings lie in the range of 66–85% and 63–82%, depending on the scenarios and reservoir types. The results clearly reveal that CAES is a promising energy storage technology for electricity supply in most of the regions. This research presents the groundwork to identify the untapped potential of CAES, which can be also utilized for the second generation of CAES such as adiabatic CAES and isothermal CAES. [ABSTRACT FROM AUTHOR]

• Adiabatic mini Compressed Air Energy Storage with artificial air vessel dynamic model. • Control strategies assessment with a dynamic model of charge and discharge phases. • Variable speed compressor and turbines strategies to enhance roundtrip efficiency. • Throttling valve as an effective solution to improve the compressor working point. • Load following assessment for typical power profiles. The increasing capacity of variable renewable energy sources fosters the importance of electric energy storage. This paper is focused on exploring Compressed Air Energy Storage (CAES) as a suitable solution for small-medium size stationary applications. A small-scale Adiabatic Compressed Air Energy Storage system with an artificial air vessel has been analysed and different control strategies have been simulated and compared through a dynamic model in Simcenter AMESim®, by identifying the most appropriate ones to improve the performance in off-design conditions. The built dynamic model allows simulating the real fluids behaviour, heat exchange, and thermofluid-mechanical inertia of its components. The proposed system is equipped with a three-stage volumetric compressor and a four-stage radial turbine. The use of variable speed compressor and turbine for both charging and discharging processes and the introduction of throttling to improve the compressor working point have been compared. Regarding the variable speed, the advantages resulted negligible for the expansion phase (+0.1% on the generated energy), while they were remarkable in the compression one. An enhancement of about 1% on the roundtrip efficiency was achieved with the variable-speed compressor and this solution demonstrated to better follow a power profile. The throttling valve was introduced to enable the reciprocating compressor to work close to nominal conditions when the pressure of the air vessel is lower than the nominal one. It allowed to strongly reduce the compression energy consumption, reaching an enhancement of about 2.3% on the round-trip efficiency. The combined use of the variable speed and throttling valve in the charging process has proven to be the best solution to reduce the compression energy consumption (-3.3%). The roundtrip efficiency enhancement of this solution (+1.8%) is lower than that obtained with the exclusive use of the throttling valve (+2.3%) because of the presence of the inverter efficiency but, simultaneously, it enables the compression group more flexible and to follow a given power profile. [ABSTRACT FROM AUTHOR]

• A standalone PV/wind/A-CAES based hybrid energy system for rural MBS is proposed. • The fan and A-CAES turbine exhaust provide cooling energy besides air conditioner. • The performance assessment of the proposed system is carried out. • The parametric sensibility and LPSP analysis are implemented. The standalone renewable powered rural mobile base station is essential to enlarge the coverage area of telecommunication networks, as well as protect the ecological environment. In this paper, a standalone photovoltaic/wind turbine/adiabatic compressed air energy storage based hybrid energy supply system for rural mobile base station is proposed. The energies from renewable sunlight and wind are the primary power sources and the adiabatic compressed air energy storage system acts as the energy buffer to manage the fluctuations in both demand and generation sides. Meanwhile, the hybrid cooling strategy is also adopted by consisting of air conditioner, fan assistant natural ventilation and turbine exhaust from adiabatic compressed air energy storage during discharge. The simulation results under design condition demonstrate that the loss of power supply probability is 0.988%, and the monthly load and individual equipment power consumption, the monthly cooling energy demand and supply and the monthly energy generation and consumption all match well. Then, the effect of photovoltaic-wind turbine configuration, the air tank volume and storage pressures of adiabatic compressed air energy storage on system performance have been implemented. Moreover, the loss of power supply probability analysis show that the required photovoltaic panels number increases with the reduced air tank volume in conditions of fixed wind power capacity and fixed 1% maximum loss of power supply probability threshold, whereas the dump load rate raises. For a certain air tank volume and maximum loss of power supply probability threshold, the dump load rate firstly reduces and then rises with the wind turbine number increases. [ABSTRACT FROM AUTHOR]