A hybrid system of latent heat storage and spray flash evaporation is devised in an attempt to develop an energy saving system, which stores intermittent thermal energy such as solar heat, waste heat or heat from the surplus steam of a power station at night and utilizes the stored energy for the generation of steam for industries, power stations and domestic air conditioning. Experimental results of the transient discharge characteristics of the heat storage column packed with the phase change material and the transient flash evaporation characteristics are reported. It is also shown that by using the numerical results of the discharge characteristics and the empirical equation of the efficiency of flash evaporation, the amount of generated steam can be predicted with sufficient accuracy. The utilization of more than 97% of the amount of stored energy for the generation of steam, substantiated experimentally, confirms the high efficiency of the present system.