Geothermal Energy

1
Geothermal Energy

• Geothermal energy is heat inside the earth.

2
What is Geothermal?

• Geothermal comes from the Greek words geo
  (earth) and therme (heat).
• Thus, geothermal energy means heat inside the
  earth.

3
The Earth Is Made of Layers
4
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.

5
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.

6
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.

7
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.

8
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.

9
Where Can We Find Geothermal Energy?

• A volcano means hot magma is near the surface.

10
Where Can We Find Geothermal Energy?

• The most active geothermal resources are usually
  found where earthquakes and volcanoes are
  concentrated.

11
Most geothermal activity occurs in an area called
the Ring of Fire.
12
Most geothermal plants in the United States are
located in the western half of the country.
13
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.

14
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 Earths core.
• We wont run out of geothermal energy!

15
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.

16
Geothermal Energy is Cheap.

• Geothermal energy is cheap new power plants can
  make electricity for about the same as coal power
  plants.

17
Geothermal Energy doesnt have to be transported.

• Geothermal plants dont 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!

18
Discussion Questions

• With all the advantages of geothermal power, why
  dont we use geothermal power more in the United
  States?
• What are some disadvantages to using geothermal
  power?