Electricity Sources

Fossil Fuels

Fossil Fuels

From Deep Within

The Electricity You Use Where does electricity come from? Electricity is not just in the wires as some

people believe. It is energy that has been transformed from one phase to another.

Remember, energy can be neither created nor destroyed, it can merely change forms.

Transforming Fossil Fuel into Electricity

This change of forms happens in places called Power Plants.

The main steps for producing electrical energy have to do with generators.

Generators are any machines that convert kinetic (motion) energy to electrical energy

The Steps to Power The generation of electricity begins with thermal

energy. A fuel (chemical energy) is burned and heats water inside pipes, causing the water to turn to steam.

The steam is directed to a turbine, and turns the blades on the shaft of the turbine. This is the mechanical or kinetic energy.

The turning shaft is connected to an electric generator which consists of a coil of wire that spins thru a magnetic field. The rotation of the coil generates electricity.

A Little About Fossil Fuels Fossil fuels are energy-rich compounds

formed from decayed plant and animal matter by a geologic process.

The three most used forms are coal, crude oil, and natural gas.

They are also non-renewable natural resources.

Non-Renewable Resources These are resources

that cannot be replenished or formed again by natural processes.

Once they are gone, they are gone forever.

As the world’s population increases the rate of use of fossil fuels increases like never before.

COAL About 300 million years ago, enormous ferns

and other prehistoric plants were common on the swamp-like earth. When those plants died and fell to the ground, they were covered with water and they slowly decomposed. As decomposition took place in the absence of oxygen, much of the hydrogen content of the matter was eroded away, leaving a material rich in carbon. The material was compressed over the years by sand and dirt, leaving the form of carbon known as coal.

Types Of Coal Coal comes in three

basic forms, lignite, bituminous, and anthracite.

The best or most efficient type of coal is anthracite which is 90% carbon.

Heat value of coal types

Coal mines

Surface (strip) mine,Western U.S. Underground (shaft) mine,

Eastern U.S.

How Coal Is Mined

Resources and Reserves of Coal It is estimated that there are 650-1000

billion tons of coal left in the earth. About 430 billion tons are in the U.S. Coal accounts for about 45% of the electric

power in the United States as of 2010. Experts believe that we have enough coal

reserves to last approximately 200 years.

Much Eastern U.S. coal hashigh-sulfur content,more expensive to mine

Much Western U.S. coal haslow-sulfur content,cheaper to mine

But mining in semi-arid West

more damaging to land.

Coal cheaper than Oil and Gas but more polluting

Oil and Natural Gas Much like coal, petroleum and natural gas are

formed from the remains of biodegraded organic material. When animals that lived in the sea millions of years ago died underwater, their remains were gradually covered by layers of very fine dirt known as "silt" on the ocean floor. Then, as the years passed, pressure from the layers built up and compressed the organic material, forming the oil and gas.

Some Facts About Oil Oil is the quickest of

the fossil fuels to form, it usually takes only about 1 million years.

At this time, the oil reserves in the world are around 640 billion barrels but not all of the oil reserves have been tapped.

Natural Gas Natural gas is the most sought after of all fossil

fuels. It burns the cleanest and is the most efficient in energy production.

Most of the natural gas in the U.S. is found in Louisiana and Texas.

An increasingly popular way to extract natural gas and oil is called fracking. It has a significant impact on air pollution and groundwater pollution and it is very common in this area of Texas.

Problems With Fossil Fuels

Are they worth it?

Air Pollution The burning of fossil fuels is the leading

contributor of smog, soot and air toxins in the United States.

The area between Houston, TX and Lake Charles, LA is one of the most polluted areas in the nation. It has been given the nickname “Cancer Alley” because of the high number of cancer cases contributed to this area. It also happens to be one of the main areas in the world for fossil fuel refining.

Acid Rain Acid rain is caused by the

burning of high sulfur coal. Sulfur dioxide is released

into the atmosphere and it combines with water vapor there. It falls to the earth in the form of acid rain.

Some places have received rain with a pH as low as 2 (comparable to lemon juice).

This lowers the pH of soil and lakes killing many fish and plants.

How Acid Rain Forms

The Greenhouse Effect You’ve all heard of what has been called the

greenhouse effect. This is what keeps the earth at a habitable temperature. The problem comes when the burning of fossil fuels radically increases the amount of carbon dioxide and nitrogen oxide in the atmosphere. The excess gases absorb infrared rays that usually escape back into space.

As a result, the earth’s temperature is rising which causes many climatic changes such as the melting of the polar ice caps and a rise in the oceans level.

What is Thermal Pollution? During the electricity-generation process, only about 65% of the energy is converted into electricity. The rest of the energy is thermal energy.

Much of this heat is released into the atmosphere or to water that is used as a coolant.

Heated air is not a significant problem but heated water, once returned to rivers and lakes, can upset the aquatic ecosystem.

Thermal Pollution