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Coal is a burnable
carbonaceous rock that contains large amounts of carbon. Coal is also a fossil
fuel—a substance that contains the remains of plants and animals and that can
be burned to release energy. Coal contains elements such as hydrogen, oxygen,
and nitrogen; has various amounts of minerals; and is itself considered to be a
mineral of organic origin.
Coal deposits come from many
epochs, but the best and most abundant are from the forests in the warm, swampy
river deltas of the Carboniferous period, some 320 million years ago.
Long
before the dinosaurs reigned, there was a time ruled by forests of giant
ferns, reeds, and mosses. The earth was a warmer, steamier place back then
and plants thrived, growing taller than our tallest trees today.

As
these plants died, they fell into the swampy waters to form rich layers of
peat. These layers were typically sandwiched between layers of sediment
like shale, deposited when waters temporarily retreated. During the
Permian period, about 290 million years ago, the seas receded entirely,
and many coastal plains turned to desert. Sedimentary rocks like sandstone
were laid down over the shale and peat. Later, limestone was laid down
when the waters returned.
In
time, the weight of the upper layers pressed down on the lower layers,
causing tremendous pressure and heat. This triggered chemical changes in
the peat, forcing out oxygen and hydrogen and leaving behind rich deposits
of carbon, called coal.
The
deeper the coal, the more pressure was exerted on it. This caused
different grades of coal—from hard, pure anthracite to softer lignite.
Between these layers lay bituminous coal, which is used in today's
electric utility power plants. Coal-based electricity provides 56% of
America's electricity.
The
Four Major Categories of Coal
Coal is classified into four categories, or ranks, based on how it
responded to increasing heat and pressure over long periods of time and
how much carbon it contains:
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Lignite
(soft): This type of coal contains a lot of moisture and ash and
breaks apart easily. Of the four types, lignite has the lowest carbon
content and heating value. Also called brown coal, lignite is
used mainly at electricity-generating plants. |
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Subbituminous
(medium-soft): This dull black coal has less moisture than lignite.
Subbituminous is generally used to produce steam for electricity
generation. Reserves of subbituminous coal are found mostly in western
states and Alaska. |
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Bituminous
(medium-hard): This type of coal, which contains very little moisture,
has high heat value. It is used to generate electricity and to produce
coke, a coal residue used in the steel industry. Bituminous coal is
the most plentiful type in the United States. |
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Anthracite
(hard): This type of coal has the highest carbon content and the
lowest moisture and ash content. Anthracite burns slowly and makes a
good heating fuel for homes. The United States has about 7.3 billion
tons of anthracite, most of which can be found in Pennsylvania. |
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Coal in Electricity
Generation
Coal is the major fuel used for
generating electricity worldwide - countries heavily dependent on coal for
electricity include (2006e):
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Poland
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93% |
Israel |
71%* |
Czech
Rep |
59% |
| S
Africa |
93%* |
Kazakhstan |
70%* |
Greece |
58% |
| Australia |
80% |
India |
69%* |
USA |
50% |
| PR
China |
78% |
Morocco |
69%* |
Germany |
47% |
A
Brief History of Coal Use
Coal is the most plentiful fuel
in the fossil family and it has the longest and, perhaps, the most varied
history. Coal has been used for heating since the cave man. Archeologists have
also found evidence that the Romans in England used it in the second and third
centuries (100-200 AD).
In the 1700s, the English found
that coal could produce a fuel that burned cleaner and hotter than wood
charcoal. However, it was the overwhelming need for energy to run the new
technologies invented during the Industrial Revolution that provided the real
opportunity for coal to fill Its first role as a dominant worldwide supplier of
energy.
In North American, the Hopi
Indians during the 1300s in what is now the U.S. Southwest used coal for
cooking, heating and to bake the pottery they made from clay. Coal was later
rediscovered in the United States by explorers in 1673. However, commercial coal
mines did not start operation until the 1740s in Virginia.
The Industrial Revolution played
a major role in expanding the use of coal. A man named James Watt invented the
steam engine which made it possible for machines to do work previously done by
humans and animals. Mr. Watt used coal to make the steam to run his engine.
During the first half of the
1800s, the Industrial Revolution spread to the United States. Steamships and
steam-powered railroads were becoming the chief forms of transportation, and
they used coal to fuel their boilers.
In the second half of the 1800s,
more uses for coal were found.
During the Civil War, weapons
factories were beginning to use coal. By 1875, coke (which is made from coal)
replaced charcoal as the primary fuel for iron blast furnaces to make steel.
The burning of coal to generate
electricity is a relative newcomer in the long history of this fossil fuel. It
was in the 1880s when coal was first used to generate electricity for homes and
factories.
Long after homes were being
lighted by electricity produced by coal, many of them continued to have furnaces
for heating and some had stoves for cooking that were fueled by coal.
Coal is our most abundant fossil
fuel. The United States has more coal than the rest of the world has oil. There
is still enough coal underground in this country to provide energy for the next
200 to 300 years.
Mining the Coal
Coal miners use giant machines to
remove coal from the ground. They use two methods: surface or underground
mining. Many U.S. coal beds are very near the ground's surface, and about
two-thirds of coal production comes from surface mines. Modern mining
methods allow us to easily reach most of our coal reserves. Due to growth in
surface mining and improved mining technology, the amount of coal produced by
one miner in one hour has more than tripled since 1978.
Surface mining is used to produce
most of the coal in the U.S. because it is less expensive than underground
mining. Surface mining can be used when the coal is buried less than 200 feet
underground. In surface mining, giant machines remove the top-soil and 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
replanted.
Underground mining, sometimes
called deep mining, is used when the coal is buried several hundred feet below
the surface. Some underground mines are 1,000 feet deep. To remove coal in
these underground mines, miners ride elevators down deep mine shafts where they
run machines that dig out the coal.
World Recoverable
Coal Reserves (Billion Short Tons)
Although coal
deposits are widely distributed, 67 percent of the world’s recoverable
reserves are located in four countries: the United States .



Source:International Energy Agency
United States Coal
Reserves

Coal Production by Coal-Producing Region,
2005 (Million Short Tons and Percent Change from 2004)
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, about 275 billion short tons. This is enough coal
to last over two hundred years at today's level of use. Coal production is the
amount of coal that is mined and sent to market. The United States produces over
a billion short tons of coal each year, over 1/5 of the world's coal.

Coal is
mined in 27 states. Wyoming mines the most coal, followed by West Virginia,
Kentucky, Pennsylvania, and Texas. Coal is mainly found in three large regions,
the Appalachian Coal Region, the Interior Coal Region, and Western Coal Region
(includes the Powder River Basin).

Appalachian Coal Region:
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Annually produces about 35% of
total U.S. coal production.
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Large underground mines and
small surface mines.
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Coal mined in the Appalachian
coal region is primarily used for steam generation for electricity, metal
production, and for export.
Interior Coal Region:
Western Coal Region:
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Annually produces about 52% of
total U.S. coal production.
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The State of Wyoming (number
one coal state) accounts for over 30% of total U.S. coal production.
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Large surface mines.
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Largest coal mines in the
world.

Coal Facts
- Coal provides
America’s railroads with more traffic and revenue than any other
commodity.
- A typical train car
holds between 115 and 117 tons of coal.
- Wyoming is the largest
coal-producing state.
- Coal accounts for half
of the electricity use in the U.S.
- Coal costs less than any
other major fossil fuel source.
- The world’s largest
producers and consumers of coal are China, Poland, Russia, India and
the United States.
- Total world consumption
of marketed energy is projected to increase by 57 percent from 2004 to
2030.
- Coal’s share of total
world energy use climbed from 25 percent in 2003 to 26 percent in 2004
and is expected to increase to 28 percent by 2030.
- America has more than
250 billion tons of recoverable coal reserves, the equivalent of 800
billion barrels of oil, more than three times Saudi Arabia’s proven
oil reserves.
- Texas is the largest
coal-consuming state in the U.S. and is the largest consumer of
electricity.
- According to an electric
power industry journal, 23 of the 25 power plants in the U.S. that
have the lowest operating costs (and therefore provide power to their
consumers at the lowest prices) are powered by coal.
- Today, America’s
coal-based generating fleet is 70% cleaner (based upon regulated
emissions per unit of energy produced) thanks, in part, to $50 billion
invested in new technologies.
- Since 1970, the use of
coal to generate electricity in the U.S. has nearly tripled in
response to growing electricity demand.
- U.S. electricity demand
continues to increase even as energy efficiency gains are made.
Despite the fact that we are continuing to become more energy
efficient, the U.S. Energy Information Administration projects that
electricity demand will grow by 41% by 2030.
- Using coal to generate
electricity is less than a 1/3 of the cost of other fuels.
- Intermittent energy
resources like wind and solar are used for meeting peak energy demand
because they are not always available. That is different from coal,
which is used to provide “baseload” power — the constant, steady
supply of electricity we depend upon throughout the day.
- America has more than
200 years of available coal reserves.
For
More Information About Fossil Fuels Click On The Links Below
credit: Energy Information
Administration, U.S. Department of Energy, World Coal institute, OPEC, Shell
Oil company,American Coalition for Clean Coal Electricity, American Coal
Foundation
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