There is a TED talk from the recent Long Beach TED conference presented by Donald Sadoway, PhD of MIT. Dr, Sadoway looked at the issues around electrical storage. His goal was to us common materials, readily available, easy to fabricate and requiring little or no maintenance. Sadoway invents to the price point of the electric utility market. so the results are quickly and easily deployed responding to immediate needs delivering immediate economic benefits. All this meets his mantra "We'll invent our way out of this economic downturn."
My interest in this idea is double headed. First if it works, and initial small commercial runs appear to be feasible, then we have a way to smooth out the power generation curves of solar and wind power in a distributed smart power network. Second the distributed energy production reduces risk to local communities and reduces the need for many new long distance transmission lines, reducing environmental impact and increasing overall utility efficiency due to the elimination of power loss over long distance transmission lines.
If we think about the possibilities of integration of storage technologies in our urban fabric and buildings and structures which act as collectors and distribution mechanisms for energy on all spectrum then we are on a road of using buildings and structures as generators and batteries rather than as appliances connected to a grid.