Green Car Congress points us to a potentially exciting new fuel cell system which uses sodium tetrahydridoborate: NaBH4 with a catalyst as the source of hydrogen fuel. The reaction is entirely inorganic (i.e., no carbon output), requires no energy, operates at ambient temperature, and the NaBH4 is non-flammable and non-explosive. The main difficulty may be cost and availability -- any chemists in the audience care to say what it takes to create sodium tetrahydridoborate?
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Apparently it is flammable and is inexpensive.