Geothermal Presentation

8/3/2019 Geothermal Presentation

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WHAT DOES THE WORD "GEOTHERMAL" MEAN?Geo = Earth Thermal = Heat

WHAT IS GEOTHERMAL ENERGY?Energy that can be extracted from the heat in the earth

Arizona

Conditions are most favorable for geothermal activity where

the earth's tectonic plates collide and one slides beneathanother. The best example of these hot regions is the PacificRing of Fire

PacificRing of fire


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HOW DOES GEOTHERMAL HEAT GET UP TO EARTH'S

SURFACE? Conduction

Heat from the Earthsinterior flows outward. It istransferred to the outer

layer of rock or the crust.

Rainwater seeping downward through poresand crevices in the crust to depths of a mile or

more is heated. The heated water may bestored at depth in geothermal reservoirs, or thehot water may flow upward out the reservoirsto the surface as hot springs, or boil near thesurface to create geysers, fumeroles, andmudpots.

Convection

In some regions, themantle beneath the

crust may be hotenough to partly meltand create magma.Magma rising upwardout of the mantle canbring intentse

shallow heat into thecrust

Magma or very hot rock


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HOW HAVE PEOPLE USED GEOTHERMAL

ENERGY IN THE PAST? Bathing:

Ancient civilizations

used hot springs forbathing

Medical Therapy:Early Romans usedgeothermal water totreat eye and skindisease

Cooking:Native Americans andothers used geothermal

water for cookingHeating:

Early Romans usedgeothermal water to

heat their homes inPompeii


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HOW DO WE USE GEOTHERMAL ENERGY TODAY?

Space Heating/Cooling

Water Heating / Spas

Aquaculture : Fish, Shrimp,Abalone, Alligators

Drying of fruits / vegetables /

lumber

Industrial Uses: Dying of cloth,washing wool, piping under

sidewalks to keep from freezing,manufacturing paper

Greenhouses: Vegetables,

flowers and other crops

Electricity Generation


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HOW MUCH ELECTRICITY IS GENERATED IN THE U.S.

FROM GEOTHERMAL ENERGY?2700 MW Today

0.4% of all

electricalgenerationEstimated

additional

capacityavailable5,000 18,000MW

Coal 53%

Nuclear 21%

Natural Gas 15%

Hydro 7%

Oil 3%

Geothermal-Wind-Solar - 1%

2003 U.S. Power Resources

Flash Technology Plant

Dry Steam Plant

Binary Plant


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HOW IS ELECTRICITY GENERATED USING GEOTHERMAL

ENERGY?

Dry Steam Power Plant

Geothermal water is passed through a heatexchanger to heat a secondary fluid thatvaporizes at a lower temperature than water.The fluid vapor spins the turbine/generator,

is condensed back to liquid and re-vaporizedat the heat exchanger.

A few geothermal reservoirs produce mostlysteam and very little water. The steam shootsdirectly through a rock-catcher and into theturbine.

The geothermal fluids are brought to the surfacethrough wells that are drilled deep into the earth. Thehot water (300 F or more) is highly pressurized. As thewater pressure is reduced during transit to the surface,30 40% of the water flashes (explosively boils) tosteam. The steam is fed to a turbine/generator toproduce electricity. The remaining water is returnedinto the earth to help maintain pressure and prolongthe productivity of the geothermal well.

Flash Steam Power Plant


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WHAT ARE SOME OF THE ADVANTAGES OF USINGGEOTHERMAL ENERGY TO GENERATE

ELECTRICITY? Clean:No emissions, safe to use

Reliable:Continuous, reliable base-load power

Sustainable / Reusable:Water can be recycled back into theearth and reusedNo other fuel mixture required to createelectricity

Land Conservative:No major land requirements. Can beintegrated into the local area with noadverse effects

Flexible / Modular:Geothermal power plants can havemodular designs, with additional unitsinstalled in increments when needed tofit growing demand for electricity


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ARIZONA LOCATIONS SHOWING TEMPERATURESAND POSSIBLE POWER PRODUCTION

Arizona Thermal Wells and Springs

Higher temperature springs andwells (greater than 50 C) occur inareas that may have potential forspace heating and geothermalgreenhousing

Some of the areas shown with wells and springs greaterthan 60 C may be underlain by reservoirs with 120 - 160temperatures and be suitable for small scale (


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HOW DOES ARIZONA USE GEOTHERMAL ENERGY

TODAY?

Safford

Marana

AquacultureGila Bend

Shrimp FarmsHyder

Tilapia Fish FarmsMarana

Winter Citrus Irrigation

Hot SpringsTonopah

Safford

Tonopah

HyderGilaBend


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Additional Sources of Information

http://www.eere.energy.gov/geothermal/

http://www.energyquest.ca.gov/index.html

http://www.azgs.az.gov/Summer2001.htmhttp://www.energy.gov/engine/content.do?BT_CODE=ENERGYSOURCES

http://geothermal.marin.org/hotsites.html

http://www.geothermal.marin.org/http://lsa.colorado.edu/summarystreet/texts/geothermal.htm

Contact Janet Crow, APS Outreach Coordinator at

(602) 250-4990 or [email protected]

Documents

Geothermal Presentation