Thermodynamic Characteristics of Underground Thermal Energy Storage System

The difference between underground thermal energy storage (UTES) and ground source heat pump (GSHP) system has been analyzed from fundamental laws of thermodynamics and heat transfer theory. The main feature of UTES system is the passive cooling or/ heating system with high energy performance, which require high grade of thermal energy to be stored, and suitable terminal system for high temperature cooling or/ low temperature heating. The storage system with thermal stratification design could maintain thermal energy quality and enhance heat transfer during storage process at large extent. As the results, UTES shows its large potential for energy efficiency.