Patent attributes
A thermal energy storing system includes two or more volumes of a formulation of active material. The formulation of active material in each of the two or more volumes includes a solvent and one or more of a salt, a base, or an acid as the active material. The formulation of active material in each of the two or more volumes also has multiple congruent solid/liquid phase transitions at different concentrations of the solvent. A phase transition temperature of each volume of the two or more volumes of the formulation of active material can be adjusted by changing the concentration of solvent in each formulation. This tunability notably improves the performance and cost effectiveness of heat pumps, shifting electrical loads to lower-cost, off-peak/renewable-intensive periods, improving efficiency, and enabling recovery of low-grade renewable and waste heat. The system has a relatively small footprint, which is particularly attractive in urban applications.