Metal hydrides have been proposed as a possible solution. We talked to a small R&D firm years ago that had proposed putting power stations in remote areas where energy is immediately converted into a metal hydride; in their case, magnesium hydride. I remember the process of reforming magnesium hydroxide back was fairly energy intensive, perhaps too much to be considered efficient.

The benefit of storing magnesium hydride is it's much easier to store safely in large volumes than hydrogen gas. Hydrogen gas leaks through everything, it's just so small. On the other hand, you have to collect spent material (presumably at "gas stations") and return it to the energy farm, which is more complex than the one-way delivery system you'd have with hydrogen. Still seemed like an interesting idea.