Abstract: A hydrogen fuel element (10, 110, 210) includes a heat-generating pyrotechnic charge (12) which comprises any suitable pyrotechnic material and an ammonia borane encasement (16, 116). The encasement partly (encasement 16) or wholly (encasement 116) encases the pyrotechnic charge (12). An ignition train (14) is powered by electrical leads (28a, 28b) to ignite pyrotechnic charge (12) to heat both the ammonia borane binder it contains and the encasement (16, 116), which itself includes or is made entirely of ammonia borane. Hydrogen is evolved from the heated ammonia borane binder and encasement. The hydrogen fuel element (10, 110) may be encased within a suitable housing (30) which may be made of a carbon open-cell foam.