1. Geothermal Energy: An Overview
Kenneth M. Klemow, Ph.D.
Wilkes University

2. As most students learn in elementary or junior high school, the earth is essentially a hot planet. Maybe not at the earth’s surface, but at depths below 20 miles, the earth becomes very hot. That heat can be harnessed to provide energy for human activities. That energy is called geothermal. Many people believe that geothermal is a promising source of alternative energy that can be tapped to replace dwindling supplies of fossil fuels that emit greenhouse gasses into the atmosphere. Others are not so sure. This presentation will provide an overview to geothermal energy. Your webquests will evaluate the degree to which it is indeed a promising alternative energy source.
© 2000 Geothermal Education Office

3. Points to be covered The deep earth as a thermal source
Direct uses of geothermal energy
Types of geothermal electrical generation
Benefits of geothermal power generation
Current levels of electrical generation capacity worldwide
Issues regarding geothermal

4. 20-65 km
(2900 km)
(6940 km)
5-6 km
© 2000 Geothermal Education Office

5. Temperature and depth Average gradient: Variation:
oC / 100m
Variation:
oC / 100m
So if assuming average, temps at depth will be:
0 m
15oC
2000 m
70oC
4000 m
120oC

6. © 2000 Geothermal Education Office

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10. Geothermal energy is used in two ways
Direct
Electrical generation

11. Direct uses of geothermal energy
www1.eere.energy.gov
geothermal.marin.org

14. Types of geothermal electrical generation
Dry steam
Flash steam
Binary cycle

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16. Geysers dry steam field in northern California
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18. Flash steam plant in Japan
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21. Binary plant in Nevada
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22. Benefits of geothermal power
Provides safe and reliable power with little land consumption
Renewable and sustainable
Provides constant baseload power
Conserves fossil fuels
Benefits local economies
Can be implemented remotely
Can prevent pollution caused by fossil fuels
© 2000 Geothermal Education Office

23. 1932
2000
© 2000 Geothermal Education Office

24. Geothermal electrical power output (2010)

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27. What is potential for geothermal energy development?
Geothermal power could serve 100% of the electrical needs of 39 countries (over 620,000,000 people) in Africa, Central/ South America and the Pacific.
(Source: link)

28. What is potential for geothermal energy development?
Using current technology, geothermal energy from already-identified reservoirs can contribute 10% of U.S. energy supply.
Inventory can grow with more exploration.
Entire world resource base of geothermal energy calculated to be larger than those of coal, oil, gas and uranium combined.
Further research and experience will improve geothermal resource base.
geothermal.marin.org/

29. What is potential for geothermal energy development?
According to Geothermal Energy Association (GEA), geothermal resources could supply over 30,000 MW of power by 2025
Equivalent to 6 percent of today's total U.S. electricity needs, and equal to 100% of the electricity generated in California, Nevada and Idaho.
geothermal.marin.org/

30. Employment in geothermal?

31. Location of geothermal potential in US

32. Geothermal heat pumps
© 2000 Geothermal Education Office

33. Benefits of geothermal heat pumps
Can be used almost anywhere worldwide
Are energy and cost efficient
Conserve fossil fuel resources
Provide clean heating and cooling; no emissions from burning fuels
Deployment: 400,000 units in U.S.
Yield: 1500 thermal mW of heating and cooling

34. Any environmental problems?
Impact
Probability of occurring
Severity of consequences
Air quality pollution L M
Surface water pollution
Underground pollution
Land subsidence
L-M
High noise levels H
Well blow-outs
Conflicts with cultural and archaeological features
M-H
Social-economic problems
Chemical or thermal pollution
Solid waste disposal

35. One clear environmental benefit

36. So, is geothermal the answer to our energy concerns?
You tell me!