A small-scale CAES (compressed air energy storage) system for stand-alone renewable energy power plant for a radio base station: A sizing-design methodology

In this paper, a novel CAES system (compressed air energy storage) is proposed as a suitable technology for the energy storage in a small scale stand-alone renewable energy power plant (photovoltaic power plant) that is designed to satisfy the energy demand of a radio base station for mobile telecommunications. The innovation introduced in this study concerns two aspects: the first one is the using of a small-scale CAES system integrated with a TES (thermal energy storage) unit with inter-cooling compression and inter-heating expansion; the second one is the cooling energy production, that is obtained by the cold air (3 °C) at the turbine outlet of the CAES system. For this reason, the storage system is defined a PSS-CAES (Polygeneration Small-Scale Compressed Air Energy Storage) system. In this paper, a sizing-design methodology of the energy power plant has been illustrated and the overall performance has been calculated. Results have highlighted that the storage system has an efficiency equal to 57%, that is an interesting value considering its small size. Moreover, the contribution of the PSS-CAES unit on the cooling energy requirements results equal to 17% with reference to the cooling energy required in the hours in which it works. •The CAES unit is the energy storage system for a stand-alone renewable energy plant.•The renewable energy plant has to satisfy the energy demand of a radio base station.•The innovation of the CAES unit concerns its size and the cooling energy production.•The CAES system is integrated with a thermal energy storage (TES) unit.•The numerical methodology allows to size the plant and to estimate its performance.