In this work the use of compressed air energy storage with air injection (CAES-AI) concept and supercharging with inlet chilling (CAES-IC) concept are discussed and analyzed. The flexibility of these technologies provides unique load management of energy. Performance is calculated for each system and compared. The operating variables in this study are discharge air mass flow, injected air mass flow, supercharging air mass flow, ambient air temperature (T-a) and overall compressors pressure ratio (PRc). The effect of these variables on the energy ratio (ER), efficiencies, and other performance parameters is evaluated. Results obtained have shown that the mean values of power generated, energy ratio, and primary efficiency of CAES-IC system are about 7% higher, 33% lower, and 1% higher than the corresponding values with CAES-AI system, respectively. The sensitivity rate of generated power, energy ratio, and primary efficiency of CAES-AI system is clearly higher than that of CAES-IC system due to ambient temperature and overall pressure ratio. (C) 2011 Elsevier Ltd. All rights reserved.