Solid–gas thermochemical sorption thermal battery for solar cooling and heating energy storage and heat transformer

Abstract

Thermal energy storage plays a vital role in the sustainable utilization of solar energy for heating and cooling applications due to its inherent instability and discontinuity. An advanced high-performance solid–gas thermochemical sorption thermal battery is developed for solar cooling and heating energy storage and heat transformer. Solar thermal energy is stored in the form of bond energy during the charging phase and the stored energy is released in the form of heat and cold energy during the discharging phase based on the energy conversion between thermal energy and bond energy of sorption potential during the solid–gas sorption process of working pair. The heat and cold energy storage densities are as high as 1300–1600 kJ/kg and 640–720 kJ/kg respectively when the sorption thermal battery using working pair of SrCl2–NH3 works as short-term and long-term seasonal energy storage. Moreover, the working temperature of stored energy can be effectively upgraded by using the sorption thermal battery. It appears that the proposed sorption thermal battery is an effective method for the short-term and long-term storage of solar thermal energy, and it has distinct advantages of combined cold and heat storage, high energy density, integrated energy storage and energy upgrade in comparison with conventional energy storage methods.