One of the major challenges with the use of solar thermal energy is the intermittent nature. As such, present day research is geared towards energy storage systems in which thermal energy is stored during the day for later use. However, in many engineering applications there is a continuous steady demand for energy. Hence, this study is focused on the optimization of a packed bed energy storage system to provide an uninterrupted continuous supply of energy in the absence of or availability of solar energy. A mathematical model was developed from consideration of the basic phenomena of heat transfer to predict the thermal behavior of a simultaneous charging, storage and discharging system during a heating cycle. Optimization of the entire storage system were carried out and it was discovered that the ratio of optimum volume to area at airflow rate of 0.0094, 0.012, 0.014, 0.017, 0.019, 0.021, 0.024, 0.026, 0.028, 0.031, 0.033, 0.035, 0.038, 0.040, 0.042 and 0.045m3/s were 0.123, 0.154, 0.185, 0.215, 0.247, 0.276, 0.308, 0.338, 0.369, 0.4, 0.43, 0.462, 0.491, 0.523, 0.554, and 0.584, respectively.