Initially I responded with poor reading comprehension, so allow me an attempt at elucidation. Elemental aluminum will react spontaneously, at room temperature,

Initially I responded with poor reading comprehension, so allow me an attempt at elucidation. Elemental aluminum will react spontaneously, at room temperature, with water; liberating hydrogen gas. The reaction is exothermic generating a lot of heat. Both the hydrogen and heat can be used for energy. Heat for heating the home in winter and the hydrogen gas for fuel cells and accessory power. The reaction needs nothing more than a reaction vessel to hold moderate pressure. A simple stainless vessel would work. The pressure being whatever you want to store your hydrogen at. More than likely, though, you would just go ahead and convert it to electricity with a fuel cell, in which case you don't need to store it. Aluminum can be stored in blocks, outside. I envisage some northern resident walking outside on a brisk morning with a hack saw and removing a chunk of aluminum to throw in his 'furnace' (reaction vessel) to warm his house and charge his phone, etc. Afterwards you need to drain off the water and collect the alumina/aluminum hydroxide and toss it in the recycling bin. Aluminum is basically free to store as energy. It requires no maintenance, no upkeep, doesn't degrade appreciably, easily transported. Hell you could build your house out of it. It's akin to wood. Use cases: Remote residences in the winter. i.e. solar is garbage and no one is shipping you a nuclear reactor.