o What is Geothermal Energy?
o Direct Applications
o Geothermal Electricity
o Advantages and Disadvantages
What is geothermal energy?
Geothermal energy is thermal energy generated and
stored in the Earth.
It originates from: the original formation of the planet
(20%) and from radioactive decay of minerals (80%).
At the core of the earth, temperatures reach over
High temperature and pressure cause some rock to
melt, creating upward magma convection. The magma
heats rock and water in the crust, sometimes up to
• Hot springs have been used for bathing since centuries. The
oldest known spa is a stone pool on China’s Lisan mountain
built in the 3rd century BC.
• The world's oldest geothermal district heating system
in France, has been operating since the 14th century.
• In 1911, the world's first commercial geothermal power plant
was built at Larderello, Italy.
• In 1960, Pacific Gas and Electric Co. began operation of the
first successful geothermal electric power plant in the USA.
• In 2010, 10715 MW of geothermal power was developed in
The oldest known pool fed by a
hot spring, built by the Qin
dynasty in the 3rd century BCE.
Today, Chevron Corporation is the
world's largest private
geothermal electricity producer.
•The Earth's internal thermal energy
flows to the surface by conduction at
a rate of 44.2 TW.
•These power rates are more than
double humanity’s current energy
consumption from all primary
sources, but most of this energy flow
is not recoverable.
•The geothermal gradient of
temperatures through the crust is 25–
30 °C per kilometer of depth in most
of the world.
•The conductive heat flux averages
•Estimates of the potential for
electricity generation from
geothermal energy vary from 0.035
to 2TW depending on the scale of
• It includes district heating, greenhouses, fisheries,
mineral recovery, and industrial process heating.
• Low-temperature (149C or less) geothermal resources
are typically used in direct-use applications.
• Today, approx. 70 countries make use of geothermal
• Iceland is the world leader in direct application of
geothermal energy. 93% of its homes are heated with
• Reykjavík, Iceland has the biggest district heating system
on the globe.
•Borehole heat exchanger is used for
•Water is sent down a well to be heated
by the Earth’s warmth.
•Then a heat pump is used to take the
heat from the underground water to the
substance that heats the house.
• Then, after the water is cooled, it is
injected back into the Earth.
The International Geothermal Association
(IGA) has reported that 10,715 MW of
geothermal power in 24 countries is
online, which is expected to generate
67,246 GWh of electricity in 2010.
This represents a 20% increase in online
capacity since 2005. IGA projects growth
to 18,500 MW by 2015, due to the projects
presently under development.
In 2010, the United States led the world
in geothermal electricity production with
3,086 MW of installed capacity from 77
power plants. The largest group of
geothermal power plants in the world is
located at The Geysers, a geothermal field
Geothermal power stations are
similar to other steam
turbine thermal power stations -
heat from a fuel source is used to
heat water or another working fluid.
The working fluid is then used to
turn a turbine of a generator,
thereby producing electricity. The
fluid is then cooled and returned to
the heat source.
•Dry steam power plants
•Flash steam power plants
•Binary cycle power plants
Installed Geothermal Electric Capacity
United States 2687 3086 0.3%
Philippines 1969.7 1904 27%
Indonesia 992 1197 3.7%
Mexico 953 958 3%
Italy 810.5 843 1.5%
New Zealand 471.6 628 10%
Iceland 421.2 575 30%
Japan 535.2 536 0.1%
Iran 250 250
El Salvador 204.2 204 25%
Kenya 128.8 167 11.2%
Costa Rica 162.5 166 14%
Nicaragua 87.4 88 10%
•Chhattisgarh government has
decided to establish the first
Geothermal Power Plant of the
country in the newly formed
Balrampur district of the state.
•NTPC has already started exploratory
and preparatory work in this area. It
has also started talks with Oil and
Natural Gas Corp and other
international organisations for drilling
•Construction work will begin in 2014.
•Around 340 hot springs have been
traced in India by the GSI over the last
India's 1st geothermal power plant to come up in
• Non conventional energy
• It is replenished by
radioactive decay of
• Unending source
• Continuous supply
• Cheap operation
• Fluids drawn from the deep
earth carry a mixture of
gases, notably carbon
dioxide , hydrogen sulfide
and ammonia which
contribute to global
warming, acid rain
• Construction is too costly
• Noise pollution
• Land survey can be