several miracles will be necessary before renewable energy (RE) is practical on a large scale (of, say, more than about 20% of electrical load) as i mentioned in my recent post about Gore's silly 100% RE claims.
one of the miracles i mentioned was that a cheap, efficient way of storing energy at a large scale would be needed.
well, one small step in that direction has been announced by a research team at MIT. one way of storing energy from RE is to break water into hydrogen and oxygen through electrolysis and later convert it back into water and recover the energy. they came up with a more efficient electrode for doing this.
the energy storage problem is still far from solved, though. being able to more cheaply produce hydrogen is nice and all, but you still have to store the hydrogen somewhere, and then cheaply convert it back into electricity at some point. and when you start talking about doing this at the large scale energy level, it quickly becomes obvious that we aren't there yet. not by a long shot.