Hydrogen propelled fuel cell vehicle system designs that reduce the relative cost of releasing hydrogen from hydrogen storage alloys by providing and/or utilizing secondary sources of heat to supply the heat of desorption of stored hydrogen. The secondary source can include combusting conventional secondary (non-hydrogen) fuels. The fuel supply system uses fundamentally new magnesium-based hydrogen storage alloy materials which for the first time make it feasible and practical to use solid state storage and delivery of hydrogen to power fuel cell vehicles. These exceptional alloys have remarkable hydrogen storage capacity of over 7 weight % coupled with extraordinary absorption kinetics such that the alloy powder absorbs 80% of its total capacity within 1.5 minutes at 300.degree. C. and a cycle life of at least 2000 cycles without loss of capacity or kinetics.