One of the most important components to optimizing our use of renewable energy is Energy Storage solutions.
The possibilities for utility level storage are many and several leading concepts were investigated in depth by a group at University of Colorado.
Some other information can be found at links below
Energy Storage Options
At this time the best prospect for wind energy storage is Compressed Air Energy Storage this link is to a study in that area.
A second area of great promise is the work being done by HSM Corporation
regarding hydrogen storage.