Thermal energy storage and phase change materials become increasingly important topics during the last 20 years for heating and cooling purpose in buildings. When there is time delay or mismatch between producing energy and energy demand, thermal energy storage provides a great solution. Furthermore, in the case of space differences between supplier and end user, the mobilized thermal energy storage can be introduced. In this solution the waste and excess heat, which is released from a factory, is recycled by storing in the PCM through heat transfer fluid and transported by a mobilized container to a consumer. In charging process the PCM is initially solid; it becomes melt while the heat transfer fluid flows inside the container. In order to achieve the highest efficiency of transferring energy in charging and discharging process, the melting and solidification times should be considered.