Thermal storage system and method

A method of operating a thermal storage system in a building, the method comprising:

• installing the thermal storage system in the building, the thermal storage system comprising:
• an electric heat pump;
• a plurality of modular cuboid thermal storage tanks having the same shape and size, each of the modular cuboid thermal storage tanks comprising:
• a tank body that includes four sidewalls and a base that define a tank cavity configured to hold a tank thermal storage liquid in a non-pressurized aqueous state that comprises a thermocline with a temperature difference between hot and cold layers greater than or equal to 20° C., the four sidewalls extending to define a rim that defines a plurality of gaps that define a respective first portion of a plurality of ports;
• and
• a removable tank lid that engages and creates a seal with the rim of the tank body, the tank lid comprising a plurality of notches that define a respective second portion of the plurality of ports;
• a plurality of heat exchanger assemblies respectively coupled to and hanging from the rim of a respective one of the plurality of thermal storage tanks into the tank cavity of the respective thermal storage tanks, with each heat exchanger assembly comprising a helical spiral or planar spiral heat exchange coil connected to inlet and outlet lines that extend through respective port plugs disposed within one or more ports of the plurality of ports of the thermal storage tank, the plurality of heat exchanger assemblies configured to run a flow of working thermal storage liquid through the respective thermal storage tanks so that heat exchange occurs between the flow of working thermal storage liquid and the tank thermal storage liquid disposed within the tank cavities of the thermal storage tanks;
• a plurality of cables that extend through existing forced-air ducting of the building that replace and provide a retrofit for a forced-air conditioning system associated with the existing forced-air ducting of the building, the cables extending through the existing forced-air ducting of the building to a plurality of separate rooms of the building to one or more forced-air receptacles in the separate rooms of the building, the plurality of cables each comprising a supply tube and a return tube that introduce a flow of the working thermal storage liquid to the plurality of separate rooms;
• a plurality of heat exchange elements disposed within the plurality of separate rooms, the plurality of heat exchange elements configured to receive the flow of the working thermal storage liquid from the plurality of cables so that heat exchange occurs between the flow of the working thermal storage liquid and environments of the respective rooms of the building;
• a set of plumbing that operably connects the electric heat pump, the plurality of heat exchanger assemblies, and the plurality of cables such that the electric heat pump can generate thermal heat in the working thermal storage liquid;
• and
• a computer device that at least automates operation of the electric heat pump and the flow of working thermal storage liquid,
• extending the plurality of cables through the existing forced-air ducting of the building that replace and provide a retrofit for a forced-air conditioning system associated with the existing forced-air ducting of the building, the cables being extending through the existing forced-air ducting of the building to the plurality of separate rooms of the building to the one or more forced-air receptacles in the separate rooms of the building;
• installing the plurality of heat exchanger assemblies in a respective one of the plurality of thermal storage tanks by hanging the plurality of heat exchanger assemblies from the rim of the respective one of the plurality of thermal storage tanks into the tank cavity of the respective thermal storage tanks, the hanging including coupling the respective exchanger assembly from the rim of the respective one of the plurality of thermal storage tanks;
• introducing a tank thermal storage liquid into the respective tank cavities of the plurality of modular cuboid thermal storage tanks;
• generating in the tank thermal storage liquid in the respective tank cavities of the plurality of modular cuboid thermal storage tanks, while in a non-pressurized aqueous state, a respective thermocline in the tank thermal storage liquid with a temperature difference between hot and cold layers greater than or equal to 20° C.;
• run a flow of working thermal storage liquid through the respective thermal storage tanks so that heat exchange occurs between the flow of working thermal storage liquid and the tank thermal storage liquid disposed within the tank cavities of the thermal storage tanks;
• and
• introducing a flow of the working thermal storage liquid to the plurality of separate rooms via the respective supply tube of the plurality of cables.