Geothermal energy harnesses heat from below Earth's surface. It is generated by radioactive decay within the earth's crust. Geothermal power plants drill wells to access hot water or steam underground, which is used to power turbines for electricity generation. There are direct uses of geothermal heat as well for heating buildings and greenhouses. While geothermal resources are limited to specific geographic locations, it provides renewable baseload power with fewer emissions than fossil fuels.

1. GEOTHERMAL ENERGY
Umashankar Mali
Sem-I
Branch-ME
3 1 / 10 / 2011 VNS institute of technology, Bhopal

2. Introduction
Geo=Earth
Thermal=Heat

3. Introduction
 Geothermal Energy is heat (thermal)
derived from earth (geo)
 Contained in rock and fluid in the earths
crust
 Source of geothermal energy is
radioactive decay

4. Geothermal energy
 Geothermal power is generated wherever water comes in
contact with hot rocks below the earth’s surface.
 The rocks give off heat that makes the water hot enough to
turn in to steam.
 Power companies can drill wells and pump the hot water or
steam to the surface, where it can be used to generate
energy.
 in areas where no underground water or steam exists
naturally, engineers can pump water into the ground to be
heated by hot rocks.
 Bolivia, Iceland, New Zealand, and the united states have
developed geothermal power plants.

5. Types and Application of
Geothermal Energy
1.Direct use
 Involves using the heat in water directly
 Temperature: 38 C-149 C
 e.g. heating of buildings, industrial processes,
greenhouses , aquaculture and resource

6. Types and Application of
Geothermal Energy
2. Ground-source heat pumps
 use the earth or groundwater as a heat source in
winter and sink in summer
 Temperatures: 4˚C to 38˚C
 Heat pump transfers heat from the soil to the
house in winter and from the house to the soil in
summer

7. Types and Application of
Geothermal Energy
3.Power generation
 geothermal power plant taps the natural supplies of
heat energy that have accumulated inside the earth.

8. Schematic energy of Geo-Thermal energy power plant

9. Geothermal energy plant

10. Indian Scenario
 Puga Valley (J&K)
 Godavari Basin Manikara (Himachal
Pradesh)
 Bakreshwar (West Bengal)
 Tuwa (Gujarat)
 Jalgaon (Maharashtra)

11. Demerits of Geothermal
Energy
 Heated water may give out after a while-
hotspot moves or aquifer pressure drops.
 Geo thermal hot spots are sparsely distributed.
 Geothermal energy is quite low grade because
the temperature of steam is only between 150
to 200 c(at 100 psi).
 salts in water can corrode equipment, shorten
lifespan.
 Limited to geographic areas where
geothermal heating naturally occurs.

12. Merits of Geothermal Energy
 Power source during construction
 Renewable as long as water is heated
naturally
 Much lower greenhouse gas emissions than
fossil fuels
 Meet the needs of electricity demand in
limited area
 An experimental unit as a pilot plant for a
larger size installation .