What Is Geothermal Energy? - Definition, Advantages & Disadvantages Video

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: What is Heat Energy? - Facts & Calculation

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:00 Geothermal Energy
  • 0:39 Capturing Earth's Heat
  • 2:13 Advantages of…
  • 3:09 Disadvantages of…
  • 3:52 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Timeline
Autoplay
Autoplay
Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Sheila Morrissey

Sheila has a master's degree in geology and has taught middle school through university-level science courses.

In this lesson, we will learn about geothermal energy, including how we capture it and use it. We will discuss the pros and cons of exploiting geothermal energy sources.

Geothermal Energy

The prefix geo-, like you've seen before in the words 'geology' and 'geography', is a Greek work meaning Earth. The term thermal is similar to the word thermometer and thermal underwear, and it means heat. We put the terms together in the word geothermal to describe heat coming from the earth. There are two sources of Earth's heat, or geothermal energy: the leftover heat from the formation of our planet and radiogenic heat, which is the heat resulting from radioactive decay within Earth. Both heat sources are naturally occurring and provide abundant energy that can be harnessed for human energy needs.

Capturing Earth's Heat

Prehistorically, and until recently, people could only make use of geothermal energy that made its way to Earth's surface, primarily as geothermal hot springs used for recreational and medicinal bathing. The oldest known pool created for this purpose was built in China in the 3rd century BCE, during the Qin dynasty. Today, geothermal baths continue to lure relaxing vacationers. The water in these hot springs is warmed as it comes into contact with rocks heated by magma below the earth's surface, so the springs are most common in volcanic areas.

In the 20th century, people started using geothermal energy for electricity generation instead of, or as a supplement to, oil, natural gas, coal, and nuclear power sources. With greater drilling capabilities came the ability to penetrate deep, underground steam reservoirs. Although geothermal energy is present everywhere on Earth, it is still most easily accessible in volcanic areas, which can typically be found above subducting tectonic plate boundaries, where one tectonic plate sinks beneath another, partially melting and creating volcanoes at the earth's surface, such as in Alaska and Japan; near divergent plate boundaries, where tectonic plates pull away from each other and magma rises to the surface, such as in Iceland; and over hot spots, where mantle material rises beneath the crust, such as in Hawaii and Yellowstone National Park. In these areas, magma is found at shallow depths, bringing geothermal heat close enough to the surface to be drilled and captured for our use at geothermal electricity stations.

Advantages of Geothermal Energy Use

Harnessing geothermal energy can have fewer environmental impacts than exploiting other energy sources. As a cleaner resource, there tends to be little airborne emissions from geothermal electricity stations. Highly developed drilling methods safely tap into geothermal energy reservoirs with little risk of releasing geothermal fluids, and the land area over geothermal reservoirs can still be used as farmland.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account
Support