The first small electrical-output wind turbines simply used modified propellers to drive direct current generators. By the mid-1920's, 1 to 3-kilowatt wind generators developed by companies like Parris-Dunn and Jacobs Wind-electric found widespread use in the rural areas of the midwestern Great Plains. These systems were installed at first to provide lighting for farms and to charge batteries used to power crystal radio sets. But their use was extended to an entire array of direct-current motor-driven appliances, including refrigerators, freezers, washing machines, and power tools.
