Thermal energy storage systems for use in material processing

An electric thermal energy storage system which delivers a process gas including:

• a first thermal energy storage (TES) unit configured to store thermal energy generated from an electric heater within the first TES unit, wherein the TES unit is configured to heat working fluid using stored thermal energy;
• at least two secondary TES units, each configured to be heated by the working fluid from the first TES unit in a first charging mode of operation and configured to heat a process gas in a second, distinct discharging mode of operation;
• multiple valves or louvers associated with the secondary TES units and configured to independently control flow into and out of each of the secondary TES units, such that individual secondary TES units can be selectively operated in the charging mode, the discharging mode, or an isolated standby mode;
• wherein the secondary TES units are configured such that when one of the secondary TES units is in the charging mode, another of the secondary TES units is in the discharging mode.

An electric thermal energy storage system which delivers a process gas including:

• a first thermal energy storage (TES) unit configured to store thermal energy generated from an electric heater within the first TES unit, wherein the TES unit is configured to heat working fluid using stored thermal energy;
• at least two secondary TES units, each configured to be heated by the working fluid from the first TES unit in a first charging mode of operation and configured to heat a process gas in a second, distinct discharging mode of operation;
• wherein the secondary TES units are configured such that when one of the secondary TES units is in the charging mode, another of the secondary TES units is in the discharging mode;
• wherein the secondary TES units are configured such that one of the secondary TES units in discharging mode has the process gas at a second pressure higher than a first pressure of working fluid in another of the secondary TES units in charging mode to prevent entry of working fluid into said one of the secondary TES units that is in the discharging mode.