High-temperature thermal energy storage and retrieval systems, devices, and processes are described that reversibly store high-temperature heat in metal hydride beds composed of titanium-containing metals or transition metal alloy that reversibly form metal hydrides at high temperatures above about 600.degree. C. and at low temperatures at or below 100.degree. C. The present invention provides exergetic efficiency up to 96% or better.
STATEMENT REGARDING RIGHTS TO INVENTION MADE UNDER FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT
 This invention was made with Government support under Contract DE-ACO5-76RL01830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention.