Nowadays, due to increase in energy consumption, a great deal of fossil fuels is being used. This latter is a consequence of the present environmental problems, such as global warming, acid rain, etc. In order to decrease these problems, the use of renewable energy sources is being promoted. But the renewable energy sources, particularly solar energy, present the drawback that there is a mismatch between the energy demand and supply. To cover this mismatch, the use of phase change thermal energy storage systems is required. In this work, the behavior of a packed bed latent heat thermal energy storage system cooperating with solar collector located in south Spain was analyzed by using a numerical method which based on Finite Volume discretization and Enthalpy Method. The model was validated by comparing obtained results with experimental data reported in the literature. The packed bed was composed of spherical capsules filled with phase change materials usable for a solar water heating system. The system was designed according to the conditions in the south Spain and by using commercial components available on the market. A series of numerical simulations were conducted applying meteorological data for several months in south Spain, particularly in Málaga.