Electric motors/generators are typically much more than 20% efficient, the usual range is 75% to 95%. And you can use that energy for things besides heating on

Electric motors/generators are typically much more than 20% efficient, the usual range is 75% to 95%. And you can use that energy for things besides heating on warm days. EDIT: The overall wind turbine isn't that efficient, that's the efficiency of the conversion of the mechanical rotation to electric power. There's a good deal of loss between the wind itself and rotation to vortices and whatnot.