Abstract: Systems and methods of energy storage and release comprise at least one storage vessel and a combined conveyor and heat transfer device linked to the at least one storage vessel by at least one discharge device. The combined conveyor and heat transfer device includes a rotatable conveyor drum and at least one heat transfer fluid conduit within the rotatable conveyor drum. A granular material travels from the at least one storage vessel to the combined conveyor and heat transfer device via the at least one discharge device, and the rotatable conveyor drum moves the granular material therethrough in counterflow to a flow of heat transfer fluid traveling through the heat transfer fluid conduit.