Evaluation of wind speed data from 12 airport sites in Wisconsin, Minnesota, Iowa, and Illinois, and from five Coast Guard stations along Lakes Superior and Michigan, indicates annual average wind speeds of 4.5 to 6 m/s and wind power densities of 100 to 200 W/sq m at 7 m height. The economic analysis of wind energy conversion systems (WECS) applied to the Dairyland Power Cooperative (DPC) system indicates that it can be economically attractive for the DPC to install WECS in the 1980s. This analysis does not include benefits due to the potential replacement of conventional capacity by the WECS. A preliminary study of WECS in combination with directly controlled water heaters shows that this combined system may delay conventional generating capacity additions longer than will controlled heaters only. A detailed reliability and cost production analysis of WECS plus direct control of a variety of loads is required to evaluate these systems accurately.