Assessment of design and operating parameters for a small compressed air energy storage system integrated with a stand-alone renewable power plant

• Published in: Journal of energy storage 2015-12, Vol.4, p.135-144
• Main Authors: Minutillo, M., Lubrano Lavadera, A., Jannelli, E.
• Format: Article
• Language: English
• Subjects: CAES system; Renewable power plant; Sensitivity analysis; Sizing procedure
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2015.10.002

•The CAES system is the energy storage unit chosen for the off-grid PV power system.•The innovation of the CAES unit concerns its size and the cooling energy production.•A sensitivity analysis is carried out by varying operating and sizing parameters.•The energy demand is satisfied both directly and indirectly by the PV power system.•Performance parameters are introduced to evaluate the power system behaviour. The renewable energy systems promotion in the field of the distributed generation is linked to the development of efficient energy storage systems. This study analyzes the behavior and the performance of a photovoltaic power system that, integrated with an adiabatic CAES (compressed air energy storage) unit, supplies electric power to a small scale off-grid BTS (base transceiver station) using only a renewable resource. The adiabatic condition of the CAES system is assured by realizing a TES (thermal energy storage) unit that recovers the heat from the inter-cooling compression for satisfying the inter-heating expansion without using additional fossil fuels. The power system is also designed to obtain a cooling effect from the cold air (3°C) at the outlet of the turbine, useful for the refrigeration of the telecommunications equipment. The aim of this study is to assess the optimal plant operating parameters, in terms of average storage pressure and operating pressure range of the air tank, considering the plant installation in three different climatic zones. The analysis has been carried out by introducing some performance parameters such as the system storage efficiency, the energy supply factor and the cooling supply factor. Results have highlighted that the best performance can be obtained by choosing both the lowest average pressure and the highest operating pressure range of the air tank.