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Hydropower is a clean renewable and reliable energy source which
converts kinetic energy from falling water into electricity without
consuming more water than is produced by nature.
Quite simply the oldest method by which renewable energy has been
harnessed by the human race. The first water wheels were used well
over 2000 years ago and the technology has since been refined to
become very efficient in the production of electricity.
The potential energy stored in a body of water held at a given height
is converted to kinetic energy (movement energy) which is used to
turn a turbine and create electricity.
Mechanical energy is derived by directing harnessing or channeling
moving water. The amount of available energy in moving water is
determined by its flow or fall.
In either instance the water flows through a pipe or penstock then
pushes against and turns blades in a turbine to spin a generator to
produce electricity. In a run of the river system the force of the
current applies the needed pressure while in a storage system water is
accumulated in reservoirs created by dams then released when the
demand for electricity is high.
Meanwhile the reservoirs or lakes are used for boating and fishing
and often the rivers beyond the dams provide opportunities for white
water rafting and kayaking.
Have you ever seen pictures of a volcano or a geyser If so then you’ve seen
geothermal energy in action!
Geo means from the earth and thermal means heat so this type of energy
is found under the earth. The hot lava from a volcano and the hot steam
from a geyser both come from underground heat and we can use that
same type of heat in our homes.
Here’s how it works about four feet underground the temperature of the
earth stays the same all year long about 55 degrees.
A geothermal heating system uses pipes buried more than four feet deep
in the earth.
The system pumps a liquid through the pipes to absorb the heat and brings
it back indoors. A device called a heat exchanger takes the heat from the
liquid and uses it to heat the air inside the home.
A geothermal system can cool your house during the summer too! It just
works in reverse absorbing the heat from the air inside your home and
moves it back into the earth.
A geothermal heater is also very energy efficient. Almost none of the
energy used is wasted so it helps keep heating bills very low during the
Wind is simply air in motion. It is caused by the uneven
heating of the Earths surface by the sun. Because the Earths
surface is made of very different types of land and water it
absorbs the suns heat at different rates. One example of this
uneven heating can be found in the daily wind cycle.
The Daily Wind Cycle
During the day the air above the land heats up more quickly
than the air over water. The warm air over the land expands
and rises and the heavier cooler air rushes in to take its
place creating wind. At night the winds are reversed because
the air cools more rapidly over land than over water.
In the same way the atmospheric winds that circle the earth
are created because the land near the Earths equator is
heated more by the sun than the land near the North and
South Poles
Wind Energy for Electricity Generation
Today wind energy is mainly used to generate electricity.
Wind is a renewable energy source because the wind will
blow as long as the sun shines.
How wind turbines work
Like old fashioned windmills today's wind machines (also
called wind turbines) use blades to collect the winds kinetic
energy. The wind flows over the blades creating lift like the
effect on airplane wings which causes them to turn. The
blades are connected to a drive shaft that turns an electric
generator to produce electricity.
With the new wind machines there is still the problem of
what to do when the wind isn't blowing. At those times
other types of power plants must be used to make
"Fossil fuels" is a general term used to described materials such as coal petroleum
and natural gas that are obtained by mining or by drilling deep into the earth.
All fossil fuels began their existence as prehistoric plants and animals. When
these creatures and plants died their matter became covered with earth and
was slowly transformed into simple organic molecules that we know today
as petroleum (oil) coal and natural gas (methane). This underground process
occurred over millions of years, at very high pressures and temperatures. Oil
and gas are obtained by drilling deep into the earth. Coal is obtained by
mining the material from deep underground. Coal has been mined for
thousands of years but the first oil well was drilled in Pennsylvania in 1859.
Fossil fuels are the major source of energy throughout the world. In the
United States oil provides 95 percent of all the energy used for
transportation. Coal is currently the leading source of energy for electrical
production, providing 53 percent of all electricity. Renewable energy sources
such as wind and solar provide less than 0.5 percent of total electricity
production. Therefore it is quite evident that fossil fuels are very important
to the quality of life in America and will be relied on for many decades to
The Future of Fossil Fuels
Today, the reality of continued use of fossil fuels for energy is spurring the
development of many new technologies to help minimize their
environmental impact. Much of this research is focused on clean coal and
petroleum technologies and greater energy efficiency. As these technologies
emerge, modern lifestyles will become more compatible with a clean