Nonrenewable Energy
Coal, crude oil, and natural gas are all types of nonrenewable energy sources. They are also all called fossil fuels because they were formed from the buried remains of plants and animals that lived millions of years ago. Uranium ore, a solid, is another type of nonrenewable energy source, and is mined and converted to a fuel used at nuclear power plants. Uranium is not a fossil fuel, but is a nonrenewable fuel.