From the viewpoints of energy saving and environmental impact, a Chemical Heat Pump (CHP) system for ecofriendly effective utilization of thermal energy is proposed. The CHP can store thermal energy in the form of chemical energy by an endothermic reaction and release it at various temperature levels during heat demand by exo/endothermic reactions. As an example, the authors propose a CHP system using the CaO/Ca(OH)2 hydration/dehydration reaction for heat storage and cold/hot heat generation. In this study, we estimate the potential of the CHP application to night-electric power utilization systems and industrial drying systems. Some systems of CHP and Chemical heat Pump Dryers (CHPD) are proposed and the potential of the systems are discussed.