Geothermal Energy -theory -source -application - GE potential (india) - Advantage & disadvantage

1. GEOTHERMAL ENERGY
HARMANJOT SINGH
L-2015-AE-32-BIV
B.TECH (FINAL YEAR)
COAE&T

2. CONTENT
•Earth Structure
•Temperature variation in earth
•Why is the interior of the Earth hot?
•Geothermal Gradient
•What is Geothermal Energy?
•Sources of Geothermal Energy
•Application of Geothermal Energy
•Geothermal Energy Potential- India
•Harmful effects on Environment
•Advantage and Disadvantage of Geothermal
Energy

3. EARTH STRUCTURE
The earth is made up of three different layers:
• the crust
• the mantle
• the core
The crust is the outermost layer of the earth
The mantle which surrounds the core It is made
up of magma and rock.
The core itself has two layers: a solid iron core
and an outer core made of very hot melted
rock, called magma.
The deeper you go, the hotter it gets

4. TEMPERATURE VARIATION IN THE EARTH

5. Why is the interior of the Earth hot?
The interior of Earth is very hot for two main
reasons:
• The heat from when the planet formed,
• The heat from the decay of radioactive isotopes
Heat from the core is constantly radiating outward
The gradual change in temperature with depth from
the surface to the core. is known as the geothermal
gradient.
In most parts of the world, the geothermal gradient
is about 25° C per 1 kilometer of depth

6. GEOTHERMAL GRADIENT

7. What is Geothermal Energy?
Geothermal energy is thermal energy
generated and stored in the Earth.
Geo means Earth
Thermal means Heat

8. Geothermal Energy contd. -
High temperature and pressure in Earth's interior
cause some rock to melt and form magma
Magma exists in the mantle and lower crust, and
sometimes bubbles to the surface as lava due to
tectonic plate movement.
Magma heats nearby rocks and
underground aquifers.
Hot water can be released through geysers, hot
springs, steam vents,
underwater hydrothermal vents, and mud pots.

9. Types of Geothermal Resources?
Geothermal Sources are Classified Based on:
 Temperature
 Physical State (i.e. water or steam),
 Type of Energy Usage
Primary Classification is Resource Temperature:
 Low Temperature Reservoir: <125°C
 High Temperature Reservoir: >200 °C

10. SOURCES OF GEOTHERMAL ENERGY
Hot water reservoirs
• As the name implies these are reservoirs of hot
underground water
Natural steam reservoirs
• In this case a hole dug into the ground can
cause steam to come to the surface

11. Sources Contd.-
Geo pressured reservoirs
• In this type of reserve, brine completely saturated
with natural gas is stored under pressure beneath
the weight of overlying rock.
• This type of resource can be used for both heat
and for natural gas
Molten magma
• No technology exists to tap into the heat reserves
stored in magma

12. Heat Extraction Method

13. Applications of Geothermal Energy
 Direct Application : Geothermal heating and
heat pumps
Indirect Application : Electricity production

14. DIRECT APPLICATION
• Extract heat from low temperature
geothermal resources < 150°C
• Applications sited near source (<10 km)
• A geothermal heat pump or ground source
heat pump (GSHP) is a central heating and/or
cooling system that transfers heat to or from
the ground.
• It uses the earth all the time as a heat source
(in the winter) or a heat sink (in the summer).

15. Direct Application contd.

16. Temperature Range of geothermal Fluid

17. Space Heating and Cooling

18. Geothermal Greenhouse
• This small greenhouse is heated with geothermal
water.
• Plants grow faster and larger when they have
additional heat available.

19. Aquaculture
• The aim of geothermal aquaculture is to heat water
to the optimum temperature for aquatic species.
• This involves the raising of freshwater or marine
organisms in a controlled environment to enhance
production rates

20. Geothermal Hot Springs

21. Indirect Application: Electricity Production
• Source temperature is higher than 150 °C
• Deep wells are drilled and steam from reservoir
is used to drive turbine and produce electricity
• Depth upto 3-5 km
• Types of Geothermal Power Plant
1. Dry steam
2. Flash steam
3. Binary cycle

22. DrySteam PowerPlants
• Dry steam extractedfrom natural reservoir
o –80-225ºC (356-437ºF)
o 4-8MPa (580-1160psi)
• Directly steamisusedto drivea turbo-generator
• Steamiscondensed and pumped back into the
ground
• Can achieve 1kWhper 6.5kgof steam
A 55MW plant requires100kg/sof steam

23. DrySteam PowerPlants

24. BinaryCycle PowerPlants
• Transfer the heat from geothermal hot water
to another liquid.
• The heat causes the second liquid to turn to
steam, which is used to drive a generator
turbine.
• Low temps –100oand150oC
• Typically 7to 12%efficent
• 0.1–40MW unitscommon

25. BinaryCycle PowerPlants

26. SingleFlashSteam PowerPlants
• take high-pressure hot water from deep inside
the earth and convert it to steam to drive
generator turbines
• Turbinedrivesan electricgenerator
• Generate between 5and100MW
• Use6to 9tonnesof steam per hour

27. SingleFlashSteam PowerPlants

28. Geothermal Energy Potential- India
The potential geothermal provinces can
produce 10,600 MW of power
 five times more than the combined output
from all non-conventional energy sources
India is in low and medium heat enthalpy zone
with resource temperature of 100
to 180 °C

29. Potential sites
Province Surface
Temp °C
Reservoir
Temp °C
HeatFlow
mW/m2
Thermal
Gradient
°C/km
Himalaya >90 260 468 100
Cambay 40-90 150-175 80-93 70
Westcoast 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

30. Most promising geothermal sites
 Puga in Jammu & Kashmir
 Cambay Graben in Gujarat
 Tattapani in Chhattisgarh
 Chhumathang in Jammu & Kashmir
 Manikaran in Himachal Pradesh
 Surajkund in Jharkhand
 Ratnagiri in Maharashtra
 Rajgir in Bihar
 Topaban in Uttarakhand
 Sohana belt in Haryana
 Bakreshwar in West Bengal
 Chintalapudi in Telangana

31. Geothermal Energy Potential in India
http://www.geni.org/globalenergy/library/renewable-energy-
resources/world/asia/geo-asia/geo-india.shtml

32. General Scenario
• Systematic efforts to explore the geothermal energy
resources commenced in 1973
• identification of 340 hot springs and 7 proven
geothermal provinces in India
• At present there are no operational geothermal plants
in India.
Ongoing Projects in India:
• Magneto-telluric investigations in Tattapani geothermal
area in Madhya Pradesh
• Magneto-telluric investigations in Puga geothermal
area in Ladakh region, Jammu & Kashmir

33. Indian organizations Participation
• Central Electricity Authority
• Geological Survey of India
• Indian Institute of Technology, Mumbai
• Regional Research Laboratory, Jammu
• National Geophysical Research Institute,
Hyderabad
• Oil and Natural Gas Corporation, Dehradun

34. EFFECTS ON THE ENVIRONMENT
DEPLETION OF RESOURCES:
• removes heat from natural reservoirs at over 10 times
their rate of replenishment
SUBSIDENCE :
• Extracting geothermal fluids can reduce the pressure
in underground reservoirs and cause the land to sink
POLLUTING WATERWAYS :
• Geothermal fluids contain elevated levels of arsenic,
mercury, lithium and boron
• These pollutants can damage aquatic life and make
the water unsafe for drinking or irrigation.

35. Air emissions :
• Geothermal fluids contain dissolved gases which are
released into the atmosphere.
• The main toxic gases are carbon dioxide (CO2) and
hydrogen sulfide (H2S).

36. Advantages
• Renewable
• Environmentally Friendly
• Reliable
• Does Not Require Fuel
• Direct Use

37. Disadvantages
• Environmental issues
• Cause earthquakes
• Start-up costs are high
• Zone Specific
• Sustainability Issues

38. THANK YOU