Variability and uncertainty are the primary challenges for power generation from intermittent, non-dispatchable energy sources. This stochastic behavior could significantly increase the cost of energy. An earlier work developed an interdisciplinary economic model using three-year (2011–2013) wind/load data from two different sites, Pennsylvania New Jersey Maryland Interconnection LLC (PJM) in USA and EirGrid in Ireland. Results showed a wind plus natural gas system can reduce emission as much as 50% below that of an all-natural gas system, with only a slight increase in system cost. Energy storage can be a key element in obtaining energy and cost savings, together with providing availability, reliability, and security of energy supply to consumers. In this paper, grid-scale storage parameters variations (storage capacity, cost, and efficiency) are explored to obtain levelized cost trends for wind systems with storage.