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+ Click on any element of the diagram for a further explanation

Production

Well

+The Production Well

The production well is a well that taps into an underground reservoir of heated water that was heated by geothermal sources

The hot water or steam is pumped to the surface through this well to be used in the later processes

Drilling the production well is the most expensive part of building and running a geothermal plant

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+Separator

The separator allows the hot water from the production well to separate into steam or water.

The steam rises into the next chamber where the turbine is, and the water is either injected back into the ground or pumped somewhere for direct heating uses, depending on the type of power plant.

The type of separator also depends on the heat of the water being pumped. If the water is pressured and superheated, then the separator is the flash chamber. However, if the water has relatively little heat and is use in a binary power plant, there is not separator at all

+Turbine and Generator

This is how the process generates electricity. The rising steam spins a turbine, which is hooked up to a generator. The mechanical energy that is produced by the turbine then runs the generator, which produced electricity

Usually, multiple turbines can be used, increasing the quantity of power generated

This part of the process is very similar to other electrical generation systems, like coal power plants, nuclear power plants, and natural gas power plants. However, geothermal energy does not have most of the cons like the other systems do.

+Condenser

Here, the steam that passed through the turbine is not condensed back into water so that it can be pumped around

This requires a large amount of cooling water, so geothermal energy usually has to be near a river

This part of the cycle also is where any leftover steam is released. This is the only thing emitted from geothermal power plants: steam. Otherwise, geothermal produces no harmful pollutants or greenhouse gases.

+Injection Well

From here, the water is injected back into the well to be reheated by the hot rocks below the surface

Sometimes, only water that was previously pumped from the same aquifer can be pumped back in. However, foreign sources of water can now be used in a process called hydro fracturing. For more information on hydro fracturing, see our science page on this website

The drilling of wells, again, is the most expensive part of geothermal energy

+Geothermal Reservoir

A geothermal reservoir is an aquifer of water that is heated by surrounding hot rocks

It is the heated water that is used for electrical generation, not the actual geothermal heat itself

Most geothermal reservoirs are a few miles below the earth’s surface, but most are also not very hot. An area with intense geothermal heat is ideal, because more power can be harnessed

+Geothermal Energy: Quiz

Test how much you know about geothermal energy! Click here to start the quiz:

+Question 1

In what ways can geothermal energy be used?

1. Electrical Generation

2. Heating Applications

3. Agricultural Applications

4. All of the above

5. Just answers 1 and 2

+Wrong!

The correct answer was 4. All of the Above

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+Correct!

Geothermal energy can be used for electrical generation, heating, and agricultural applications

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+Question 2

Which type of geothermal field is the most common?

1. Dry Steam Fields

2. Wheat Fields

3. Hot Water Fields

4. Wet Steam Fields

+Wrong!

The correct answer was 3. Hot Water Fields

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+Correct!

Hot water fields are the most common type of geothermal field.

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+Question 3

How do geothermal energy power plants produce electricity?

1. By harnessing natural electric currents under the earths’ surface

2. By harnessing geothermal heat in the form of steam that then spins a turbine

3. By harnessing geothermal heat in the form of steam that then passes directly through a generator

+Wrong!

The correct answer was 2. By harnessing geothermal heat in the form of steam that then spins a turbine

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+Correct!

Geothermal power plants produce electricity by harnessing geothermal heat in the form of steam that then spins a turbine

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+Question 4

The household heating and cooling system that uses temperatures a few yards below the surface to control temperatures is…

1. One common form of geothermal energy

2. An indirect form nuclear energy

3. An old, outdated form of geothermal energy

4. Not really geothermal at all

+Wrong!

The correct answer was 4. Not really geothermal at all

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+Correct!

That type of heating and cooling system, called geoexchange is not a real form of geothermal energy, contrary to common belief

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+Question 5

What is a binary power plant?

1. A power plant that uses conduction and a working fluid to spin the turbine

2. A power plant that uses steam to spin the turbine

3. A power plant that exclusively specializes in binocular production

4. A power plant that flashes steam which then spins the turbine

+Wrong!

The correct answer was 1. A power plant that uses conduction and a working fluid to spin the turbine

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+Correct!

A binary power plant uses conduction from the hot hydrothermal sources to heat a secondary, working fluid, which vaporizes and spins a turbine

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+Question 6

Pumping down pressurized water to crack a rock, then filling the crack with small beads is a process called:

1. Fuel Fabrication

2. Hydrothermal locating

3. Water Injection

4. Hydro Fracturing

+Wrong!

The correct answer was 4. Hydro Fracturing

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+Correct!

Hydro fracturing is the process of pumping down pressurized water to crack a rock, then filling the crack with small beads

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+Question 7

Why is geothermal technology considered to be advanced?

1. Geothermal technology has gone through significant testing and advances

2. Aliens gave us their geothermal technologies

3. Similar technologies from the petroleum industry have been highly developed and then converted to geothermal uses

4. A great deal of people are interested in geothermal energy, so they all try to improve its technologies

+Wrong!

The correct answer was 3. Similar technologies from the petroleum industry have been highly developed and then converted to geothermal uses

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+Correct!

Advances in petroleum drilling technologies have influenced very similar geothermal drilling technologies

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+Question 8

Which of the following is NOT a con to geothermal energy?

1. Drilling wells can be very expensive

2. Geothermal power emits harmful gases into the air

3. A large amount of cooling water is needed

4. Geothermal power plants can be an eyesore

+Wrong!

The correct answer was 2. Geothermal power emits harmful gases into the air

This statement is not a con, because geothermal only releases mildly irritating gases if any, not harmful gases

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+Correct!

That statement is not a con, because geothermal only releases mildly irritating gases, if any, not harmful gases

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+Question 9

Where can harnessable geothermal heat be found?

1. In places with significant geothermal activity only a few miles below the surface

2. Only in places with a cold climate

3. In your own backyard!

4. The locations are random

+Wrong!

The correct answer was 1. In places with significant geothermal activity only a few miles below the surface

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+Correct!

Geothermal heat is only found in places with geothermal activity only a few miles below the surface

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+Question 10

What was the first use of geothermal energy by people?

1. Electrical generation

2. Bathing and cooking in hot springs and geysers

3. Pumped heating systems

4. No one really knows

+Wrong!

The correct answer was 2. Bathing and cooking in hot springs and geysers

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+Correct!

The first use of geothermal energy by humans was bathing in hot springs and cooking with geysers

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+That’s the end of the quiz

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