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

© 2000 Geothermal Education Office

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  The WebQuest  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  The WebQuest

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

Temperature and depth  Average gradient:  o C / 100m  Variation:  o C / 100m  So if assuming average, temps at depth will be:  Average gradient:  o C / 100m  Variation:  o C / 100m  So if assuming average, temps at depth will be: 0 m15 o C 2000 m70 o C 4000 m120 o C

© 2000 Geothermal Education Office

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Geothermal energy is used in two ways Electrical generation Direct

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

Types of geothermal electrical generation  Dry steam  Flash steam  Binary cycle  Dry steam  Flash steam  Binary cycle

© 2000 Geothermal Education Office

Geysers dry steam field in northern California © 2000 Geothermal Education Office

Flash steam plant in Japan © 2000 Geothermal Education Office

Binary plant in Nevada © 2000 Geothermal Education Office

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  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

© 2000 Geothermal Education Office

Geothermal electrical power output Producing CountrymW in 1999 Total8217 United States2,850 Philippines1,848 Italy769 Mexico743 Indonesia590 Japan530 New Zealand345 Iceland140 Costa Rica120 El Salvador105 geothermal.marin.org

© 2000 Geothermal Education Office

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)link  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)link

What is potential for geothermal energy development?  Using current technology, geothermal energy from already-identified reservoirs can contribute 10% of U.S. energy supply.  With more exploration, inventory can become larger.  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.  Using current technology, geothermal energy from already-identified reservoirs can contribute 10% of U.S. energy supply.  With more exploration, inventory can become larger.  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/

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.  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/

Employment in geothermal?

Location of geothermal potential in US

Geothermal heat pumps © 2000 Geothermal Education Office

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  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 Deployment: 400,000 units in U.S. Yield: 1500 thermal mW of heating and cooling

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

One clear environmental benefit

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