Energy Fact Sheet
Coal
What Is Coal?
Coal is a fossil fuel created from the remains of plants that lived and died about 100 to 400 million years ago when parts of the earth were covered with huge swampy forests. Coal is called a nonrenewable energy source because it takes millions of years to form.
The energy we get from coal today comes from the energy that plants absorbed from the sun millions of years ago. All living plants store energy from the sun in a process called photosynthesis. After the plants die, this energy is usually released as the plants decay. Under conditions favorable to coal formation, however, the decay process is interrupted, preventing the further release of the stored solar energy.
Millions of years ago, dead plant matter fell into the swampy water, and over the years, a thick layer of dead plants lay decaying at the bottom of the swamps. Over time, the surface and climate of the earth changed, and more water and dirt washed in, halting the decay process. The weight of the top layers of water and dirt packed down the lower layers of plant matter. Under heat and pressure, this plant matter underwent chemical and physical changes, pushing out oxygen and leaving rich hydrocarbon deposits. What once had been plants gradually turned into coal.
History of Coal in America
North American Indians used coal long before the first settlers arrived in the New World. Hopi Indians, who lived in what is now Arizona, used coal to bake the pottery they made from clay.
European settlers discovered coal in North America during the first half of the 1600s. They used very little coal at first. Instead, they relied on waterwheels and burning wood to power colonial industries.
Coal became a powerhouse by the 1800s. People used coal to manufacture goods and to power steamships and railroad engines. By the time of the American Civil War, people also used coal to make iron and steel. And by the end of the 1800s, people even used coal to make electricity.
Today coal provides about 22 percent of America's energy needs. The major use of coal is to making electricity.
Coal Mining
Coal miners remove coal from the ground. They use two methods surface mining and underground mining.
Surface mining is the method used most often to remove coal from the ground. This method can be used when the coal is buried less than 200 feet underground. In surface mining, giant machines remove the topsoil and underlying layers of rock to expose large beds of coal. Once the mining is finished, the dirt and rock are returned to the pit, the topsoil is replaced and the area is seeded. The land can then be used for croplands, wildlife habitats, recreation, or commercial development.
Underground mining is the method used when the coal is buried deep within the earth. Some underground coal mines sink 1,000 feet deep! To extract coal in underground mines, miners go down a deep shaft and operate machines to remove the coal.
Processing and Transporting Coal
After coal comes out of the ground it goes to a special plant, called a preparation plant, for cleaning The "prep" plant removes rock ash, sulfur, and other impurities from the coal. Cleaning improves the heating value of coal. After cleaning, the coal is ready to go to market. Long trains transport most coal to market. Sometimes river barges, trucks, and conveyor belts are used to ship coal. In one place, coal is crushed and mixed with water for transport by pipeline. Transportation is very important because sometimes it costs more to ship coal than to mine it.
Coal Reserves and Coal Production
Coal reserves are beds of coal still in the ground waiting to be mined. The United States has the world's largest known coal reserves. If we continue to use coal at the rate we use it today, we will have enough coal to last about 285 years.
Where is most of the coal in the United States found? Montana has the most coal reserves. It is followed by Illinois, Wyoming, Kentucky, and West Virginia.
Coal production is the amount of coal that is mined and sent to market. Coal is mined in 27 states. Wyoming mines the most coal, followed by Kentucky, West Virginia, Pennsylvania, and Texas. </S3>
How Coal Is Used
Most coal today is used to make electricity. Some electric plants are built near coal mines to reduce the cost of transporting coal over long distances.
The steel and iron industries are also big coal users. They use coal as a fuel for smelting metals. Other industries use coal too. The paper, brick, limestone, and cement industries all use coal to make their products.
Contrary to popular belief, very little coal is used today for heating homes and other buildings. Coal furnaces, which were popular years ago, have largely been replaced by natural gas or oil furnaces or electric heat pumps.
Coal and the Environment
Coal is a plentiful energy source. Unfortunately, it is America's dirtiest fuel. That is why the coal industry is now working on ways to make coal cleaner.
People in the industry believe that removing most of the sulfur in coal before it is burned will help reduce air pollution. When coal is burned, a chemical called sulfur is released into the air where it combines with oxygen to form sulfur dioxide. Many scientists think sulfur dioxide is linked to acid rain, a condition which may have harmful effects on wildlife (especially fish) and forests. The coal industry now uses "scrubbers" to remove most of the sulfur from coal smoke.
The industry is also concerned about the carbon dioxide that is produced when coal is burned. Carbon reacts with oxygen in the air to form carbon dioxide. This gas, along with the gases from automobiles, collect in the earth's atmosphere where they form a shield. The shield lets the sun's heat in, but doesn't let it out. This condition is called the greenhouse effect.
Picture and Tables
Picture 1
Dinosaurs lived 100 million years ago
Coal formed form dead plants before the dinosaurs 300 million years ago
Picture 2
How coal was used in 1995 (by %)
Electric Utilities-88%
Coke Plants-3%
Other Industry-8%
Residential Heating-1%
75% is Non-production Time
