PRESENT TRENDS IN THE USE OF
GEOTHERMAL ENERGY
Presented by:
Geothermal energy: power
from the earth
Geothermal energy is the energy
produced by heat within the Earth.
water deposits in the Earth’s crust are
heated by geothermal energy.
The United States is the world’s
largest producer of geothermal energy.
Steam rises through a well, it drives turbines, which generate electricity.
Geothermal energy technologies
can be broken into four major
categories:
- Conventional hydrothermal, low-temperature,
EGS(Enhanced Geothermal Systems) and direct use, including geothermal heat
pumps (GHPs).
The first three categories generate
electricity, while the fourth is used
EGS-A NEW TECHNOLOGY
Until recently, geothermal power systems
have only exploited resources where
naturally occurring water and rock porosity is sufficient to carry heat to the surface.
Enhanced Geothermal Systems (EGS) are
a new type of geothermal power
technologies that do not require natural convective hydrothermal resources.
EGS technologies "enhance" and/or create
HOW EGS WORKS?
The permeability can be enhanced by
pumping high pressure cold water
down an injection well into the rock.
Water travels through fractures in the
rock, capturing the heat of the rock.
Heat captured is converted into
Development of
Geothermal Power:
Project Cycle
The primary stages of the geothermal
development cycle are
:-
exploration,
Resource confirmation,
drilling and reservoir development,
plant construction and power
production.
Each of these steps carries with it
Development
Constraints:- include factors such as the comparative low
cost of petroleum and gas and environmental issues.
Energy source such as wind, solar and
hydro are more popular and better
established; these factors could make developers decided against geothermal.
Harmful gases can escape from deep within
GEOTHERMAL ENERGY IN
INDIA
India has reasonably good potential for
geothermal; the potential geothermal provinces can produce 10,600 MW of power.
But yet geothermal power projects has not
been exploited at all, owing to a variety of reasons, the chief being the availability of plentiful coal at cheap costs.
India will need to start depending on clean
Technologies used in
India
Flashed steam plant.
Dry steam plant.
Flashed steam
plant:-
The extremely hot water from drill
holes when released from the deep
reservoirs high pressure steam (termed
as flashed steam) is released.
This force of steam is used to rotate
Dry steam
plant:-
Usually geysers are the main source of
dry steam. Those geothermal reservoirs
which mostly produce steam and little
water are used in electricity production
systems.
As steam from the reservoir released, it
Hybrid power
plant:-
Some geothermal fields produce boiling
water as well as steam, which are also
used in power generation.
In this system of power generation, the
flashed and binary systems are
combined to make use of both steam
and hot water.
Efficiency of hybrid power plants is
Total investment in geothermal energy
from 1973 to 1995 was about US$22
billion, and the industry continues to
grow at about 16 percent per annum in
electricity generation and about 6
percent in direct uses.
If present trends continue, geothermal
electricity generating capacity could
increase from about 10,000 MW at the
start of 2000, to 58,000 MW in 2020.
Trends:-Trends in U.S.& international
- Installed capacity: 9.7 Gwe
Production: 60 TWh
24 countries; 5 produce 15-22% of electricity from geothermal (Costa Rica, El Salvador,Iceland, Kenya, the Philippines).
R&D to use 87- 120ºC water to generate electricity in binary schemes (0.3-3 MWe) –
USA, Austria, Germany, Iceland
• Direct uses:
Installed capacity: 27 825 MWe,
Production: 261 418 TJ/2005
50% for heating (GHGs limitation!)
for 72 countries
2000 – 2004: 50% increase of installed
capacity and heat use
GEOTHERMAL USES, 2008 - 2009
•Power generation
Nesjavellir power plant, Iceland
Trends in geothermal
energy A case study on
TURKEY
Unlike the world trend, utilization of heatpumps and development of enhanced
geothermal systems have not gained any footage in Turkey.
Heat pump utilization is very limited due to
its high capital costs. Carbon credit’s
exchange may not be feasible given the high CO2 content of most of Turkey’s high enthalpy geothermal resources.
On the other hand, geothermal power
Economics of geothermal
Power Generation in
Turkey:-
A stochastic study was conducted on
economics of geothermal resources in
Turkey (Serpents, 2005).
As for electricity generation, this type of
utilization looks profitable with the
electricity selling prices of around 6
cents/kWh.
The payout time for this type of
investments reaches 7 to 8 years.
The profitability increases with the
Why Our Geothermal Resources
Have Not Been Properly Developed
There are many problems hindering the
development of geothermal resources of
Turkey. These can be summarized in 3
categories:
technical,
economical, and
