Reduction of wind power variability through geographic diversity
  The variability of wind-generated electricity can be reduced by aggregating the outputs of wind generation plants spread over a large geographic area. In this chapter we utilize Monte Carlo simulations to investigate upper bounds on the degree of achievable smoothing and clarify how the degree of smoothing depends on the number of plants and on the size of the geographic area over which they are spread. 
Mark Handschy, Stephen Rose, and Jay Apt
physics.ao-ph stat.AP