Abstract

A method and apparatus are disclosed for transferring heat to or from metal hydrides contained in storage containers as hydrogen gas is being charged to or withdrawn from the storage containers, wherein the hydrogen gas being charged to or withdrawn from the storage containers functions as a convective energy carrier. A plurality of the containers are connected together in flow communication in series, so that when a pressure differential is established across the series of containers, hydrogen gas associated with the metal hydride will flow from one container to the next container in the direction of the lower pressure. A pressure differential is created across the series of containers by charging hydrogen to either the first or last container in the series, or by withdrawing hydrogen from either the first or last container in a series of containers that has been previously charged with hydrogen. Hydrogen gas flowing through the conduits connecting adjacent containers is heated or cooled in heat exchanger means associated with the conduits. The pressure differential across the series of containers can be periodically reversed by periodically alternating charging hydrogen to the first and last containers of the series during the charging of said containers, and by periodically alternating the discharge of hydrogen from the first and last containers of the series when hydrogen is being withdrawn from the series of containers.