Thermal storage is a crucial element of solar-dynamic space power systems. Storing heat in solid-liquid phase-change materials is not ideal. These materials are usually highly corrosive salts, and undercooling and heat-transfer temperature differentials cause significant deviations from ideal isothermal conditions. Metal hydrides are equivalent to molten salts in terms of heat storage per unit mass but store more heat per unit volume. In addition, hydrides may enable recovery of stored heat without a reduction in temperature. This effect may be achieved by using pairs of metal hydrides operating in tandem to pump waste heat from the radiator loop to the receiver. A temperature swing in one of the two hydrides overcomes the irreversible energy losses of storing and recovering heat from the other. In effect, this provides isothermal heat storage for maintaining rated output from the power system while the stored heat is recovered. Phase I would compare alternate concepts and prepare for the fabrication of a ground test article in Phase II.
Potential Commercial Applications: Hydride thermal storage could be applied in terrestrial solar electric power and in thermal load-leveling for batch processing at high temperatures in chemical industries.STATUS: Phase I Only
