Thermal storage device

A thermal storage device 1 comprises a thermal storage core 11, a plurality of heating elements 15a-c, a temperature sensor 13, and a safety temperature threshold circuit 20. The thermal storage device also comprises a circuit breaker circuit 22a-c for each of the plurality of heating elements. The temperature sensor is disposed in the thermal storage core and configured to output a temperature signal representative of a temperature of the thermal storage core. The safety temperature threshold circuit is configured to receive the temperature signal and output a safety signal when the temperature signal indicates that a temperature of the thermal storage core is below a safety temperature threshold of the safety temperature threshold circuit. Each circuit breaker circuit is configured to allow the supply of electrical energy to the respective heating element upon receiving the safety signal from the safety temperature threshold circuit. When the safety signal is not received, each circuit breaker circuit is configured to prevent the supply of electrical energy to the respective heating element.