This article reviews that flow batteries can turn intermittent wind power from a utility manager’s burden to a green and reliable energy source. Customers and the popular press have made it exceedingly clear that they expect wind, solar, and other renewable energy sources to play an increasingly important role in generating the electricity that powers modern society. This desire is often driven by concerns about air quality, public health, and energy security, among other factors. For a utility planner, any intermittent source is not dispatchable. A dispatchable energy source can be scheduled for use at the planner’s convenience. Among renewable energy sources, hydroelectric and geothermal facilities are also dispatchable, within the natural limits of the resource availability.