The wind industry should be aware of the ReDox Bulk Energy System, which was originally invented and patented by the NASA Lewis Research Center in Cleveland in the 1970s. It was described then as a versatile electro-chemical storage system that has the energy in/out characteristics of a lead acid battery with a virtually unlimited life span. The Reagan Administration terminated work on storage system technology, for politial rather than economic or scientific reasons, it seems. Today the ReDox patents have lapsed and are available in the public domain.
A feasible storage system would radically change the economics of wind energy and its place in the pecking order of energy sources. Not only would it make existing wind farms more competitive, but it would spawn a whole new area of research. I believe ReDox is the solution. A company in North Carolina is marketing small versions of this system.