Fossil Fuels - the problem with energy
What are fossil fuels?
There are three main fossil fuels used in the United States today -- crude oil, coal and natural gas. Oil, natural gas and coal were formed millions of years ago from decaying plants and animals. This organic material decayed and built up thick layers. Over time, the mud and soil changed to rock, covered the organic material and trapped it under the rock. Heat and pressure from these layers turned the remains into oil, coal, and natural gas.
Fossil fuels are dirty fuels. Despite their relatively inexpensive paper cost, fossil fuels have a huge environmental and social cost that is often papered over or ignored. The coal industry, for example, has a "clean coal" campaign to position it as more acceptable "clean" fuel. Meanwhile, renewable energy advocates are pushing for increased use of solar energy, wind power and other alternative energy sources like geothermal, biomass, and biofuels.
Oil - liquid fossil fuel
Oil is the most widely used fossil fuel. Our society has experienced more change over the last one hundred years than was seen in the previous ten thousand years -- all because of the accessibility of a relatively cheap and highly efficient supply of energy -- oil.
We are deeply dependent on oil to power our cars, trucks and airplanes, for lubrication, dyes, drugs, plastics and synthetic materials. The widespread use of oil brought about the development of the automobile, enabling Americans to be much more mobile. It facilitated the production and distribution of affordable consumer goods and through advances in healthcare doubled an American citizen’s life expectancy in just 100 years.
The United States is the world’s largest consumer of oil -- we use nearly 25% of global consumption.
While the benefits of oil are amazing, there are significant costs: burning oil gives off carbon dioxide, a greenhouse gas that is linked to global warming. The use of petroleum products gives off carbon monoxide, nitrogen oxides, particulate matter, and unburned hydrocarbons that form air pollution. The world’s supply of oil is finite. We will eventually run out and must, therefore, make it a priority to develop renewable energy sources to substitute for oil’s essential role in our lives. Estimates of the decline in oil production, the peak oil theory, have been hotly debated for decades.
Coal - solid fossil fuel
Coal is the next most widely used fossil fuel after oil. The United States has the world’s largest known coal reserves, about 263 billion tons. This is enough coal to last about 225 years at the current rate of use.
Coal is mined in 27 states. Wyoming has the most coal, followed by West Virginia, Kentucky, Pennsylvania, and Texas.
92% of all the coal mined in the U.S. is used for generating electricity. Coal-fired electric utility companies produce half of all the electricity generated in the United States. Coal’s by-products are used to manufacture fertilizers, medicines, plastics, tar and synthetic fibers. The concrete and paper industries burn large quantities of coal. Coal is the key ingredient in smelting iron ore into steel. About 4 percent of the coal mined in the United States is exported.
Coal mining and burning is not kind to the environment. Surface mining strips topsoil and rock to expose large beds of coal. Without proper care, mining can destroy land and pollute water. When coal is burned as a fuel it releases carbon dioxide, the main greenhouse gas which causes global warming. Coal burning also creates emissions such as sulfur, nitrogen oxide, and mercury that can pollute the air and water.
Natural gas - gaseous fossil fuel
Most of the natural gas used in the United States is produced in the United States. Some is imported from Canada in pipelines.
Natural gas can be chilled to very cold temperatures (-260 Fahrenheit), which changes it into a liquid. As a liquid it takes up much less room, only 1/600th of the space that it would take in a gaseous state. Natural gas in this liquid state is known as LNG or Liquefied natural gas. It can be transported via truck in this format. Most natural gas travels though pipelines directly to the homes or buildings where it will be used.
Around 22 percent of the energy expenditure of the U.S. comes from natural gas. About 50 percent of U.S. homes heat using gas.
Natural gas is the vital raw material for products such as paints, fertilizer, plastics, antifreeze, dyes, photographic film, medicines, and explosives. It is used to manufacture steel, glass, paper, clothing, brick and electricity.
More than 60 percent of homes use natural gas to fuel stoves, furnaces, water heaters, dryers and other household appliances.
Natural gas is the cleanest of the fossil fuels. It has fewer discharges of sulfur, carbon, and nitrogen than coal or oil. When it is burned, it releases very little particulate matter.
Uranium - the other fuel
Uranium is the most widely used fuel in nuclear plants. Nuclear power plants produce 20% of our country’s electricity. Uranium provides about 4% of the world’s non-renewable energy. Nuclear plants use a certain kind of uranium, U-235, as its atoms are easily split apart. Though uranium is easily found, U-235 is rare. So when uranium is found, the U-235 must be extracted and processed or “enriched” into U-235 concentrations to be used as fuel for nuclear power plants.
U-235 and U-238 are found in nearly all rock, soil, and water. U-238 is the most plentiful form in the environment.
Uranium is an extremely heavy metal. Enriched uranium can be in the form of small pellets that are packed into long tubes used in nuclear reactors.
Compared to electricity produced by burning fossil fuels, nuclear energy is clean. No air pollution or carbon dioxide is produces.
Nuclear power plants produce two types of waste: high level and low level. High-level waste includes the spent fuel from the nuclear reactor. It is highly radioactive and dangerous. Special care must be taken to store it. Low-level waste can come from nuclear reactors or from hospitals or universities. It can be shipped to low-level waste disposal facilities.
Source: US Department of Energy