Transcript Geothermal - Pearland ISD

Geothermal Energy
Geothermal energy is heat inside the earth.
What is Geothermal?
Geothermal comes from the
Greek words geo (earth) and
therme (heat).
Thus, geothermal energy means
heat inside the earth.
The Earth Is Made of Layers
The Earth Is Made of Layers
At the center is a core of iron.
Around that is an outer core of iron
and rock so hot the rock is
melted.
The liquid rock is called magma.
The next layer is a mixture of rock
and magma called the mantle.
The shell of the earth – with the
oceans and mountains - is called
the crust.
Heat Inside the Earth
• The inside of the earth
is very hot.
• Sometimes this heat
comes near the surface
in the form of magma.
• We can use this heat to
warm our houses and
make electricity.
How Do We Use Geothermal Energy?
People have used geothermal energy for heating
and bathing for thousands of years.
Hot springs are pools of water that are warmed
by underground springs, so they are always hot.
How Do We Use Geothermal Energy?
• Today, power plants use
steam from geothermal
wells to make
electricity.
• The steam is used to
spin turbines.
• The turbines spin
magnets in coils of
copper wire to make
electricity.
Where Can We Find Geothermal Energy?
• Even though geothermal
energy is underground,
there are visible features
on the surface.
• These include
volcanoes, hot
springs, and geysers.
Where Can We Find Geothermal Energy?
A volcano means hot magma is near the surface.
Where Can We Find Geothermal Energy?
The most active geothermal resources are usually found
where earthquakes and volcanoes are concentrated.
Most geothermal activity occurs in an
area called the Ring of Fire.
Most geothermal plants in the United States are
located in the western half of the country.
Geothermal Energy in the United States
Geothermal energy produces only a
small percentage of U.S.
electricity.
Today, it produces about 15 billion
kilowatt-hours, or less than one
percent of the electricity
produced in this country.
Geothermal Energy is Renewable.
 The hot water we use will be replaced by rain.
 The heat inside the earth will always be there.
 More heat is made every day in the Earth’s
core.
We won’t run out of geothermal energy!
Geothermal Energy is Clean.
 No fuel is burned,
so there is no air
pollution.
 The steam is
turned into water
and put back into
the earth.
Geothermal Energy is Cheap.
 Geothermal energy
is cheap – new
power plants can
make electricity for
about the same as
coal power plants.
Geothermal Energy doesn’t have to
be transported.
 Geothermal plants don’t transport fuel –
they sit on top of their fuel source.
 Geothermal power plants have been built
in deserts, in the middle of crops, and in
mountain forests!
Discussion Questions
• With all the advantages of geothermal
power, why don’t we use geothermal
power more in the United States?
• What are some disadvantages to using
geothermal power?