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geothermal power

OLogy Series
geology
card
303

geothermal power

OLogy Series
geology

Miles below your feet, scorching temperatures can get hot enough to melt rock. In some places, water heated deep underground rises to the surface in hot springs and geysers. Earth's internal heat, called geothermal power, can be an important energy source. In some places, steam released from underground is used to turn turbines, creating electricity.

Geothermal plants don't have to be located near hot springs or geysers. Geothermal power can also be tapped by:

building geothermal plants deep underground

heating above-ground water with electric coils

injecting water into hot spots deep underground

Are you right?

Correct!

In these geothermal systems, engineers drill down to rocks deep underground where temperatures are about 400 degree Fahrenheit. Then they inject cold water and capture the steam released when the water is heated.

Today, geothermal energy heats 90% of homes in Iceland. This is no surprise, since Iceland is a geologic hot spot, home to many:

volcanoes

geysers

both of these

Are you right?

Correct!

Iceland is located where two tectonic plates (giant pieces of Earth's crust) are slowly spreading apart. Magma rising up between the plates produces the volcanoes and geysers that are so common to the region.

Some geothermal energy plants could cause small earthquakes.

Fact
or
Fiction
?

Fact

Deep drilling operations can cause the ground to become unstable. Sometimes this may cause small earthquakes or tremors.

There is a limited supply of geothermal energy within Earth.

Fact
or
Fiction
?

Fiction

Geothermal energy is a renewable resource. That means it will not run out. It is also consistent. It does not change from season to season or year to year.

Most scientists think that geothermal power could provide much of the electricity needed by the United States by 2050.

Fact
or
Fiction
?

Fiction

In reality, experts think advanced geothermal power plants may provide the U.S. with about 5% of its electricity by 2050.

Definition: heat energy from within Earth
Carbon Dioxide Emissions: very light (but does cause water and air pollution)
Cost: expensive (vs. other energy sources)
Location: near above ground and underground hot spots, where magma rises to Earth's surface.
Current Use: less than 0.5% of energy in the U.S.
Cool Fact: Geothermal plants release under 1% of the carbon dioxide released by coal-fired power plants.

Image credits: courtesy DOE/NREL / Pacific Gas & Electric.