This document provides an overview of geothermal energy, including its history, types of geothermal power plants, potential sources in India, costs and environmental impacts. Hot springs have been used since ancient times for bathing. The Romans built the first commercial baths heated by geothermal springs. Modern uses include generating electricity via dry steam, flash steam and binary cycle power plants. India has significant geothermal potential, especially in the Himalayan region. While geothermal energy has low emissions, exploration and development costs are high due to uncertainty around usable resources underground.

1. MECHANICALMECHANICAL
ENGINEERINGENGINEERING

2. Geothermal energyGeothermal energy
Sagathiya NaisargSagathiya Naisarg
Prepared
by

3. HistoryHistory
Hot springs have been used forHot springs have been used for
bathing at least since paleolithic times. Thebathing at least since paleolithic times. The
oldest known spa is a stone pool onoldest known spa is a stone pool on
China's Lisan mountain built in the QinChina's Lisan mountain built in the Qin
Dynasty in the 3rd century BC, at theDynasty in the 3rd century BC, at the
same site where the Huaqing Chi palacesame site where the Huaqing Chi palace
was later built.was later built.
In the first century AD, RomansIn the first century AD, Romans
conqueredconquered Aquae SulisAquae Sulis, now Bath,, now Bath,
Somerset, England, and used the hotSomerset, England, and used the hot
springs there to feed public baths andsprings there to feed public baths and
underfloor heating. The admission fees forunderfloor heating. The admission fees for
these baths probably represent the firstthese baths probably represent the first
commercial use of geothermal power.commercial use of geothermal power.
The world's oldest geothermal districtThe world's oldest geothermal district
heating system in Chaudes-Aigues, France,heating system in Chaudes-Aigues, France,
has been operating since the 14th century.has been operating since the 14th century.
The earliest industrial exploitation began inThe earliest industrial exploitation began in
1827 with the use of geyser steam to1827 with the use of geyser steam to
extract boric acid from volcanic mud inextract boric acid from volcanic mud in
Larderello, Italy, Italy
[1]

4. INTRODUCTIONINTRODUCTION
Geothermal energyGeothermal energy is a veryis a very
powerful and efficient way topowerful and efficient way to
extract a renewable energy fromextract a renewable energy from
the earth through natural process.the earth through natural process.
this can be performed on a smallthis can be performed on a small
scale to provide heat 0 for ascale to provide heat 0 for a
residential unit(residential unit(a geothermala geothermal
heat pumpheat pump),or on a very large),or on a very large
scale for energy production throughscale for energy production through
a geothermal power planta geothermal power plant..
[2]

5. [3]

6. Generation of Electricity isGeneration of Electricity is
appropriate for sources >150appropriate for sources >150oo
CC
Dry Steam plantsDry Steam plants
These were the firstThese were the first
type of plantstype of plants
created. They usecreated. They use
underground steamunderground steam
to directly turn theto directly turn the
turbines.turbines.
[3]

7. Flash Steam PlantsFlash Steam Plants::
These are the mostThese are the most
common plants. Thesecommon plants. These
systems pull deep, highsystems pull deep, high
pressured hot water thatpressured hot water that
reaches temperatures of 360reaches temperatures of 36000
FF
or more to the surface. Thisor more to the surface. This
water is transported to lowwater is transported to low
pressure chambers, and thepressure chambers, and the
resulting steam drives theresulting steam drives the
turbines. The remaining waterturbines. The remaining water
and steam are then injectedand steam are then injected
back into the source fromback into the source from
which they were taken.which they were taken.
[3]

8. Binary Cycle PlantsBinary Cycle Plants
This system passesThis system passes
moderately hot geothermalmoderately hot geothermal
water past a liquid, usuallywater past a liquid, usually
an organic fluid, that has aan organic fluid, that has a
lower boiling point. Thelower boiling point. The
resulting steam from theresulting steam from the
organic liquid drives theorganic liquid drives the
turbines. This process doesturbines. This process does
not produce any emissionsnot produce any emissions
and the water temperatureand the water temperature
needed for the water isneeded for the water is
lower than that needed inlower than that needed in
the Flash Steam Plantsthe Flash Steam Plants
((25025000
F – 360F – 36000
FF).).
[3]

9. Potential Geothermal regions/sources in IndiaPotential Geothermal regions/sources in India
Province Surface Temp C Reservoir Temp C Heat Flow Thermal gradient
Himalaya >90 260 468 100
Cambay 40-90 150-175 80-93 70
West coast 46-72 102-137 75-129 47-59
Sonata 60 – 95 105-217 120-290 60-90
Godavari 50-60 175-215 93-104 60
With India’s geothermal power potential of 10,600 MW, the
following are the potential sources/ regions where
geothermal energy can be harnessed in India.
[4]

10. Different GeothermalDifferent Geothermal
Energy SourcesEnergy Sources
Water ReservoirsWater Reservoirs: As the name implies: As the name implies
these are reservoirs of hot underground water.these are reservoirs of hot underground water.
There is a large amount of them in the US, butThere is a large amount of them in the US, but
they are more suited for space heating than forthey are more suited for space heating than for
electricity production.electricity production.
Natural Stem ReservoirsNatural Stem Reservoirs: In this case a: In this case a
hole dug into the ground can cause steam tohole dug into the ground can cause steam to
come to the surface. This type of resource iscome to the surface. This type of resource is
rare in the US.rare in the US.
Geopressured ReservoirsGeopressured Reservoirs: In this type: In this type
of reserve, brine completely saturated withof reserve, brine completely saturated with
natural gas in stored under pressure from thenatural gas in stored under pressure from the
weight of overlying rock. This type of resourceweight of overlying rock. This type of resource
can be used for both heat and for natural gas.can be used for both heat and for natural gas.
[Wiki]

11. PROGRESS OF GEOTHERMALPROGRESS OF GEOTHERMAL
ENERGYENERGY
Geothermal electricityGeothermal electricity generationgeneration
is currently used in 24 countries,is currently used in 24 countries,
[1][1] while geothermal heating is usewhile geothermal heating is use
inin 7070 countriescountries
[2][2] current world wide installedcurrent world wide installed
capacity iscapacity is 1017510175 megawatts, withmegawatts, with
the largest capacity in the unitedthe largest capacity in the united
states(states(30863086 mw).mw).
[3][3] the emission intensity ofthe emission intensity of
existing geothermal electric plants isexisting geothermal electric plants is
on averageon average 122122 kg ofkg of co2co2 perper
megawatt hour of electricity, aboutmegawatt hour of electricity, about
one eighth of a conventional coalone eighth of a conventional coal
fired plantfired plant produces 4 times theproduces 4 times the
energy that they consume.energy that they consume.
[6]

12. Harmful effect of GeothermalHarmful effect of Geothermal
 Extracting large amounts of waterExtracting large amounts of water
can cause land subsidence, and thiscan cause land subsidence, and this
can lead to an increase in seismiccan lead to an increase in seismic
activity. To prevented this the cooledactivity. To prevented this the cooled
water must be injected back into thewater must be injected back into the
reserve in order to keep the waterreserve in order to keep the water
pressure constant underground.pressure constant underground.
 Power plants that do not injectPower plants that do not inject
the cooled water back into the groundthe cooled water back into the ground
can release Hcan release H22S, the “rotten eggs”S, the “rotten eggs”
gas. This gas can cause problems ifgas. This gas can cause problems if
large quantities escape becauselarge quantities escape because
inhaling too much is fatal.inhaling too much is fatal.
[wiki]

13. Costs of Geothermal EnergyCosts of Geothermal Energy
1)1) Costs highly variable by sitCosts highly variable by sit
2)2)Dependent on many cost factorsDependent on many cost factors
3)3) High exploration costsHigh exploration costs
4)4) High initial capital, low operating costsHigh initial capital, low operating costs
5)5)Fuel is “free”Fuel is “free”
6)6) Significant exploration & operating riskSignificant exploration & operating risk
7)7)Adds to overall capital costsAdds to overall capital costs
8)8)““Risk premium”Risk premium”
[wiki]

14. Indirect CostsIndirect Costs
Availability of skilled laborAvailability of skilled labor
Infrastructure and accessInfrastructure and access
Political stabilityPolitical stability
Indirect CostsIndirect Costs
Good: 5-10% of direct costsGood: 5-10% of direct costs
Fair: 10-30% of direct costsFair: 10-30% of direct costs
Poor: 30-60% of direct costsPoor: 30-60% of direct costs
[wiki]

15. Geothermal ProspectsGeothermal Prospects
 Environmentally veryEnvironmentally very
attractiveattractive
 Attractive energyAttractive energy
source in rightsource in right
locationslocations
 Likely to remain anLikely to remain an
adjunct to other largeradjunct to other larger
energy sourcesenergy sources
 Part of a portfolio ofPart of a portfolio of
energy technologiesenergy technologies
 Exploration risks andExploration risks and
up-front capital costsup-front capital costs
remain a barrierremain a barrier
[7]

16. ReferencesReferences
[1]http://www.conserve-energy-[1]http://www.conserve-energy-
future.com/GeothermalEnergyHistory.phpfuture.com/GeothermalEnergyHistory.php
[2] www.gvepinternational.org/renewablee[2] www.gvepinternational.org/renewablee
[3]http://energyalmanac.ca.gov/renewables/geothermal/types.html[3]http://energyalmanac.ca.gov/renewables/geothermal/types.html
[4]http://indianpowersector.com/home/renewable-[4]http://indianpowersector.com/home/renewable-
energy/geothermal/energy/geothermal/
[5]http://www.renewableenergyworld.com/rea/tech/geothermal-[5]http://www.renewableenergyworld.com/rea/tech/geothermal-
energyenergy
***http://en.wikipedia.org/wiki/Geothermal_energy***http://en.wikipedia.org/wiki/Geothermal_energy
[6]http://www.greenprogress.com/alternative_energy.php?[6]http://www.greenprogress.com/alternative_energy.php?
subcat=geothermlsubcat=geotherml
[7]http://www.radiusgold.com/s/JV-Available.asp?[7]http://www.radiusgold.com/s/JV-Available.asp?
ReportID=414160&_Title=Guatemala-Geothermal-ProspectReportID=414160&_Title=Guatemala-Geothermal-Prospect
***http://en.wikipedia.org/wiki/Geothermal_energy***http://en.wikipedia.org/wiki/Geothermal_energy

17. Thank you
Thank you
For
For
W
atching
W
atching
carefully
carefully