Jim Logajan wrote:
Bertie the Bunyip wrote:
The volume thing is a non-issue with metal hydride tanks as well as
the safety issue.

The information I've found on metal hydrides is not nearly so
optimistic. Allegedly about 4 times heavier per unit of energy than
gasoline and many of the known metal hydrides (e.g. lithium)
themselves being health hazards.

One other issue with metal hydrides for storage of hydrogen is the energy
needed to load/unload them. The loading with hydrogen is an exotherm
process, while refuelling your typical family car in 5-10 minutes for a
range of 300 miles (comparable to a liquid hydrocarbon fuel), you would have
to dissipate around 400 kW of heat energy. To retrive the hydrogen, you have
to put that same energy back into the storage unit by heating it.

regards,
Friedrich