Whether nuclear power will become a major energy source in the future is uncertain. Much depends on continued advances in nuclear technology, the cost of alternative fuels, the need for and cost of foreign oil, and environmental concerns. Events such as those associated with Three Mile Island and Chernobyl encourages reassessment of continued expansion of nuclear power. Thus, the extent to which uranium and thorium will be used for energy purposes in the future is difficult to predict. Furthermore, the supply of uranium in the United States may not be enough to meet a large long-term demand.
Wind turbines convert kinetic energy into mechanical power.
This mechanical power can be used for many tasks, such as grinding grain or pumping water or a generator can convert this mechanical power into electricity to power homes, business, and schools. In the United States, millions of windmills were erected as the American West was developed during the late 19 th century. Most of them were used to pump water for farms and ranches. By 1900, small electric wind systems were developed to generate direct current, but most of these units fell into disuse as inexpensive grid power was extended to rural areas during the 1930s. By 1910, wind turbine generators were producing electricity in many European countries.