OLogy Cards > geothermal power

geothermal power

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. And engineers can harness the steady temperatures underground closer to Earth’s surface to warm and cool buildings.

Stats

Definition: heat energy from within Earth
Carbon Dioxide Emissions: very light (but does cause water and air pollution)
Cost: depends on the location; generally expensive (vs. other energy sources)
Location: Most geothermal plants are built near above-ground and underground hot spots, where magma rises to Earth’s surface, but heat pumps for cooling and heating buildings can be built around the world.
Current Use: less than 1% of energy worldwide
Cool Fact: Geothermal plants release under 1% of the carbon dioxide released by coal-fired power plants.

Stumper

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

Correct!

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

Stumper

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

volcanoes

geysers

both of these

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.

Fact or Fiction

There is a limited supply of geothermal energy within Earth.

Fact

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.

Fact or Fiction

Some geothermal energy plants could cause small earthquakes.

Fact

Fiction

Fact

Deep drilling operations can cause the ground to become unstable. So can injecting water deep underground. Sometimes this may cause small earthquakes or tremors.

Fact or Fiction

Geothermal power can heat and cool entire neighborhoods.

Fact

Fiction

Fact

Communities are building geothermal networks. They drill holes in convenient spots and build underground pipes to carry heated or cooled water where it’s needed. Some colleges heat and cool all the buildings on campus this way.

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

You might also like...

Explore the connections between technology, population and rising atmospheric CO₂.

Here are some things that you and your family can do to save energy and be climate champions. Some of these are easy, some are harder, and some are fun! Everything you can do helps.

For thousands of years, humans have relied on the power of wind to sail across oceans, pump water, and grind grain.

Correct!

Correct!

Fiction

Fact

Fact

You might also like...

Rising CO2

Be an Energy Saver

Card 300: wind power