Fossil fuels are a type of fuel made from prehistoric plants and animals. Humans extract fossil fuels from the earth and burn them to generate energy. Fossil fuels have a lot of energy stored inside them because they have a high carbon content. Since fossil fuels take millions of years to form and are burned to generate electricity, they are considered a finite resource, or non-renewable.
Coal, oil and natural gas are the three types of fossil fuels. Coal is a black sedimentary rock found throughout the world. According to the U.S. Department of Energy, “one quarter of the world’s coal reserves are found in the United States,” and coal provides “half of the electricity consumed by Americans.” Oil is a dark liquid composed of diatoms, or tiny photosynthetic algae, and other forms of organic matter that were buried underground over 300 million years ago. Naturalgas.org states that natural gas is an colorless, odorless gas which is found in pockets underneath the earth’s surface.
Fossil fuels are all formed in the same way. The California Energy Commission states that during the carboniferous period, about 360 to 286 million years ago, large quantities of organic matter, such as trees, ferns and algae, were buried underneath layers of mud and sediment. Over time more and more layers of rock and sediment formed on top of these organic deposits, which slowly pressed the moisture out of them, leaving behind fossilized remains. Depending on their chemical composition, these fossilized remains formed coal, oil or natural gas.
Some fossil fuels are found underground in pockets that are formed from the movement of the earth. Energy companies find these pockets of fossil fuels underground, drill into them and pump the oil or natural gas to the surface. The American Coal Foundation states that coal is found in deposits in the ground and must be mined and physically removed.
According to the U.S. Department of Energy, the burning of fossil fuels satisfies 85 percent of the energy needs of the United States. Fossil fuels are burned to heat water until it becomes steam. The steam turns turbines that power generators. The generators create electricity, which is sent to homes and businesses to be used for light, heat or anything that requires electricity. Once a fossil fuel has been burned, it cannot be used again.
In addition to creating electricity, oil and natural gas can used to create many different products. Through a process called refinement, crude oil is separated into different parts and turned into different products, such as gasoline and plastic products. Creating gasoline is the most important function of oil refinement. About 50 percent of a barrel of crude oil is converted into gasoline, while the remaining 50 percent is made into other petroleum products.
