High performance metal hydride based thermal energy storage systems for concentrating solar power
Thermal energy storage (TES) systems based on metal hydride pairs using new class of high efficiency materials are evaluated. The use of low temperature metal cost effective material such hydrides NaAlH4 and Na3AlH6 became possible. In order to obtain high efficiency at reasonable cost high temperature materials were altered by the addition of materials to form reversible alloys and hydrides. The compounds were cycled to determine stability of hydrogen capacity over extended number of cycling. A thermal energy storage system based on two metal hydride pairs such as CaAl/CaH2/Al:NaAlH4, Ca2Si/CaH2/Si:Na3AlH6 and NaMgH2F—Si/Mg2Si—NaF:Na3AlH6 allows low cost and high efficiency performance.