Abstract: A thermal energy storage (“TES”) device including a vessel housing a continuous volume of a TES media, an input portion, an output portion, and a plurality of thermal energy transport members connected to the input portion and/or the output portion. The input portion receives thermal energy from a thermal energy source. The received thermal energy is transported by one or more of the thermal energy transport members to the output portion and/or the TES media for storage. One or more of the thermal energy transport members connected to the output portion transport stored thermal energy from the TES media to the output portion. The output portion is coupled to an external device, such as a Stirling engine, and configured to transfer thermal energy the external device. Optionally, selected ones of the thermal energy transport members connected to both the input and output portions may be insulated from the TES media.