I think it is so coll that you are gettig to do this. It always seems to me "if money were no object" how much better things could be done. To me the whole idea of batteries just seems an old broken path. Problem is.. any other idea is currently just not available to common folk.
I always thing of most resouces as a storage meduim for energy. Here in MS .. water ( free rain water) is pleantiful.. so my ideas seem revolve around using that as a storage.
excess electricity + H2O = H2 and O2...
When you need heat/power burn the H2
Of course a fuel cell would be the bomb
as would sodium-sulfer batteries
http://en.wikipedia.org/wiki/Sodium%E2%80%93sulfur_battery