Wind generators produce electrical energy by using a windmill to drive a generator. They are very efficient and can produce massive quantities of electricity for their size. However to cover for when there is no wind an energy storage system such as a battery bank is needed.
Aermotor windmills or wind powered water pumps have been long used by farmers and ranchers to water their livestock. Since the pumps work only when the wind is blowing a reservoir such as a cistern or elevated water tank is necessary to store the water to supply it to a house.