Geothermal Energy - University Of Massachusetts Boston

Geothermal EnergyPresented byManisha Sarin11/13/2007

Geothermal energy Geo-earth Thermal-heat heat is continuouslyproduced inside the earthand the water isreplenished by rainfall. clean and sustainable a.jpg

Energy inside the earthInner core-solid ironOuter core-magmaMantle-magma and rockThe heat flows outwardtowards from the earth’sinterior. The crustinsulates the earth fromthe interior ld003.htm

Temperature inside the earth Crust is broken into piecescalled plates Magma erupts through theedges of plates Deep underground the rocksand water absorb the heatfrom this sld004.htm

Where is geothermal energy found The most activegeothermal resources areusually found along themajor plate boundarieswhere most volcanoesand earthquakes areconcentrated. Ring of fire isconcentrated around thepacific ocean. newable/geothermal.html

Plate tectonic processes In the middle of the ocean newcrust is formed. When theplates meet they slide over oneanother and large amount ofmagma rises from the edge ofsinking plates most magmadoes not reach the surface butcauses the large regions ofunderground rock to heat up.

Geothermal reservoir The rising hot waterand steam is trappedin the permeable andporous rocks under alayer of impermeablerock, a geothermalreservoir is formed. .htm

The rainwater can seep through the faults and cracks and get heatedup it may return to the surface of water as springs ,geyser, mud pots orfumaroles (holes where the volcanic gases are released)

Exploration and drilling Satellite imagery andaerial photography-anumber of satelliteimages are takenthrough artificialsatellites Volcanologicalstudies-volcanoes arenatural indicator ofunderground heat .htm

Rocks are carefully examined and the temperaturegradient data is collected

Power plants Dry steam Flash steam Binary type

Dry Steam Power Plant The steam (and no water) shoots up the wells and ispassed through a rock catcher (not shown) and thendirectly into the turbine. Dry steam fields are rare.

Flash steam power plants use hot water reservoirs. In flashplants, as hot water is released from the pressure of thedeep reservoir in a flash tank, some if it flashes to steam.

. from geothermal water is usedIn the binary type power plant, the heatto vaporize a "working fluid" in separate adjacent pipes. The vapor,like steam, powers the turbine generator.

Enhanced Geothermal Systems (EGS)Hot Dry Rock Geothermal System Water is pumped through the injectionwell and superheated steam isreturned through the production wellUseful heat is extracted and water canbe recirculated.Can cause earthquakes. The HDRproject in Basel, Switzerland wassuspended after causing anearthquake. On 8, December,2006,only 8 days after water injectionstarted, a quake occurred measuring3.4 on the Richter scale with theepicenter at the bottom of the HDRborehole. r/hdr.shtml

The MIT report calculated the world's total EGS resources to be over 13,000ZJ, ofwhich over 200 ZJ would be extractable, with the potential to increase this to over2,000 ZJ with technology improvements - sufficient to provide all the world's energyneeds for several millennia.AdvantagesThe processed waste water can be usedIt can be used anywhere as compared to tectonicallyactive areasDisadvantages-Requires deeper drilling.-Can cause earthquakes.

Geothermal heat pumps(geo exchange systems) Residential and commercial heating andcooling without a geothermalreservoir .

Benefits of geothermal heat pump Can be used anywhere in the world Extremely cost and energy efficient No emission of harmful gases from theburning of fossil fuels Conservation of fossil fuel.

Worldwide geothermal power generation in early 2005CountryUSAChinaAnnual energyproduced in GWh/yearNumber of units17,91796Percent of nationalenergy209 0.513 30% of TibetEl Salvador9675 22France1022 9Guatemala2128 3Iceland148319 17.2Indonesia608515 6.7Italy534032 1.9Japan346719 0.3Kenya1088Mexico628236 3.1New Zealand277433 7.1Nicaragua2713 9.8Philippines925357 19.19 19.2

Geothermal energy Potential in theUS

Geothermal energy in Iceland In Iceland, there are five major geothermalpower plants which produce about 26%(2006) of the country's electricity . Geothermal heating meets the heatingand hot water requirements for around87% of the nation's housing. Iceland is located on the mid Atlanticridge, which makes it one of the mosttectonically active places in the world

Uses Balneology ( hot spring and spa bathing)major tourist attraction Agriculture ( green house and soilwarming) Aquaculture (fish/prawn and alligatorfarming) Industrial uses (product dying andwarming) Residential and district heating

Advantages of using GE Energy harnessed is clean and safe for the surroundingenvironment. Sustainable as the hot water used in the GE plant can bere injected into the ground to produce more steam. InEGS the treated waste water can be re injected into theground. Geothermal power plants are unaffected by changingweather conditions. Extremely price competitive. Reduces reliance on fossil fuels Great scalability

Disadvantages of GE Highly localized resource. it is greatest along fault linesand around volcanic regions Construction of power plant can adversely affect the landstability in the surrounding region. The initial cost to build a geothermal power plant isexpensive.

References The future of geothermal energy, Idaho National LaboratoryBertani Ruggero (2005) world geothermal power generation in theperiod 2001-2005 geothermics,volume 34,651-690Geothermal education office, US department of energyGeothermal power,wikipediaHurter S and Schell Schmidt R,fuels and ickson H and Fanelli M Institute di Geoscienze e Georisorse,international geothermal association.Environmental and Energy Study Institute (EESI). 2006. GeothermalEnergy: Tapping the Energy in the Earth’s Core. Online at

Geothermal education office, US department of energy Geothermal power,wikipedia Hurter S and Schell Schmidt R,fuels and energy abstracts,geothermics,2003,32,(4-6),779-787 Dickson H and Fanelli M Institute di Geoscienze e Georisorse, international geothermal association. Environmental