Wind is a type of solar energy. It is created by the uneven heating of Earth’s surface by the Sun. Windmills have been used on farms to pump water and grind grain. Some remote areas also used wind-powered electric generators. The need for these lessened when electric companies strung wires across America. On wind farms, wind is converted into electricity using large wind turbines. The kinetic energy of falling water can be harnessed to turn a wheel. Flowing water is used to generate electricity in a process called hydroelectricity. This method causes little pollution and is readily available. However, building large dams can damage the environment.