Nonrenewable energy sources include fossil fuels, such as petroleum, coal and natural gas. Uranium for nuclear power is a nonrenewable energy source that is not a fossil fuel. Once these sources are exhausted, they can’t be replaced in the span of a lifetime.
Fossil fuels are fossilized organic matter formed through millions of years of plant and animal decomposition under the earth’s surface. Fossil fuels require extraction by mining and drilling. Petroleum must be refined and processed into gasoline and other fuel products. None of these fossil fuels, which are used in homes, businesses, manufacturing and transportation, can be reproduced or manufactured. Although nuclear power, used to generate electricity, is not a fossil fuel, it is a nonrenewable resource because the source of nuclear power is a rare type of uranium, U-235, which is expensive to mine, process and extract from uranium ore.