Solid state hydrogen storage typically only gets you to a maximum of 20% hydrogen by weight, which is equivalent to ammonia. Ammonia also lets you liberate all

Solid state hydrogen storage typically only gets you to a maximum of 20% hydrogen by weight, which is equivalent to ammonia. Ammonia also lets you liberate all of the hydrogen, whereas hydrides don't. If you want to use hydrogen for aviation, LH2 is really the best answer, since the percentage hydrogen by weight is much higher. The next best thing would probably be an sofc using hydrocarbon fuel, if you really wanted to go electric, but still needed endurance.