• Major Energy Resources
• Non Renewable Resources Fossil Fuels – Coal,
Petroleum, Natural gas, Biofuels, Biogas, wood
• Renewable Resource
• Nuclear
• Solar
• Hydropower
• Wind Power
• Tidal and Ocean Thermal
• Geothermal
Observations of Climate Change – Global
Warming
Temperature, Evaporation & rainfall are increasing;
More of the rainfall is occurring in downpours
Corals are bleaching
Glaciers are retreating
Sea ice is shrinking
Sea level is rising
Wildfires are increasing
Hurricane, storm and flood damages are much larger
Fission of 1 kilogram of
uranium releases more
energy than does burning 3
million kg of
coal.
Nuclear Power
Geothermal Features associated
with groundwater
• Hot springs
• Water is 6-9oC warmer than the
mean annual air temperature of
the locality
• The water for most hot springs is
heated by cooling of igneous rock
Features associated with
groundwater
• Geysers
• Intermittent hot springs
• Water erupts with great force
• Occur where extensive underground
chambers exist within hot igneous rock
• Groundwater heats, expands, changes
to steam, and erupts
Evolution of a
geyser eruption
Yellowstone Geyser erupting – geothermal energy for a ‘Supervolcano’
Geothermal Energy is energy stored in the form of
heat beneath the surface of the solid earth
Geothermal Energy can be spectacular!
Photos of US Geological Survey
Geysers and
volcanoes show the earth’s heat
What is geothermal energy?
Geothermal energy is heat from Earth’s interior. Geothermal heat
originates from Earth's fiery formation more than four billion years ago.
At Earth's core— 7900 km (4,000) miles deep - temperatures may reach
over 6000 degrees Centigrade, 9,000 degrees Fahrenheit
•Direct Sources function by
sending water 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 it is cooled
is injected back into the Earth.
•Ground Heat Collectors This
system uses horizontal loops filled
with circulating water at a depth of
80 to 160 cm underground.
Borehole Heat Exchange
This type uses one or two underground
vertical loops that extend 150 meters
below the surface
‘Ring of Fire’
Hawaii
Pacific Ocean
High-Enthalpy Geothermal Energy world-wide
Graph from Geothermal Education Office, California
Sources of Earth’s Internal Energy
•About 70%
comes from the
decay of
radioactive nuclei
with long half
lives that are
embedded within
the rocks in
lithosphere and
mantle
•Some energy is
from residual heat
left over from
Earth’s formation.
Temperature increases with depth in
Lithosphere
Geothermal Energy is energy stored in the form of heat
beneath the surface of the solid earth. Geothermal gradient
Normally 20 to 30º C / km, 1300-1400º C at base of
lithosphere, 3000-6000º C + in core
Lithosphere
Mantle
Outer Core
Inner Core
Graph from Geothermal Education Office, California
Geothermal Power: Natural
steam is extracted from wells to
power the turbine generator.
The left-over cool water is
pumped down to sustain
production.
Hawaii Geothermal Area
The Hawaii geothermal area includes the Puna Geothermal
Venture, which is located about 38 km (21 miles) south of
Hilo on the Big Island of Hawaii. The facility is situated along
the Lower East Rift Zone of the Kilauea Volcano. At the Puna
Geothermal Venture, geothermal fluid is brought to the surface
through production wells, which tap into the resource at a
depth of almost a mile. The steam, along with its noncondensable gases, is routed to the power plant and used to
produce electricity for the Big Island of Hawaii.
Benefits of Volcanoes:
Geothermal Energy - One of the
benefits of volcanism is
geothermal power. The
geothermal power plant on
Kilauea's east rift zone is shown
here. Pu'u O'o is up-rift from
this plant. (This photo was taken
on December 29, 1989.) The
drilling has encountered some of
the hottest underground fluids
yet found. At a depth of 1,969 m
the hole has a temperature of
350 degrees C. Increased
development of Hawaii's
geothermal resources is under
consideration
Hawaii Geothermal Inter-island
Submarine Cable Project Proposed
Route (Fesmire and Richardson, 1990).
Map of the major islands of Hawaii showing the
location of the 20 Potential Geothermal Resource
Areas (PGRAs)
HAWAII AND GEOTHERMAL
WHAT HAS BEEN HAPPENING?
There is still resistance to using geothermal energy
by some members of he local population even though the
above issues have been and will continue to be addressed by
the government and the developers. However there are well
organized groups and various community organizations that
will continue to express concern in various ways about the
ability of the government and developers to provide socially
and environmentally sound geothermal power. Further, the
level of support given by the state’s political establishment to
expansion of geothermal capacity–
The 30 megawatt (MW) PGV plant uses air-cooled condensers
and noise reduction enclosures. It’s a low-profile plant, 8
meter, 24 feet high, and has near zero emissions. Geothermal
fluid and gas is reinjected into the deep earth.
Puna Geothermal Venture geothermal power plant provides
about 20% of electricity demand on the Big Island of Hawaii.
Global Warming and the Fossil Fuels:
There are approximately 1700 kWh of electricity in a barrel of
fuel oil, however, power plants are, on average, 31% efficient
and an additional 5% of that energy is lost in transmission
from source to user. Thus, 1700*0.31*0.95 = 501 net kWh per
barrel.
Burning of a barrel of crude oil 0.43 tons of carbon dioxide are
released into the environment. A barrel has 42 gallons, one
gallon produces 0.011 tons.
Steam Engine
Internal
Combustion
Engine
Piston
Steam Engine
Effect on Coastal Areas
Lava from Kupaianaha pond enters the ocean near Kalapana and extends
the coastline (December 27, 1989). Intermittent littoral (sea shore)
explosions added spatter to a large littoral cone on top of the sea cliff.
Lava flows temporarily destroy land. However, when these same flows
reach the sea, new land is added to the total area of the island.
Different Geothermal Energy Sources
Hot Water Reservoirs: As the name implies these are
reservoirs of hot underground water. There is a large amount
of them in the US, but they are more suited for space heating
than for electricity production.
Natural Steam Reservoirs: In this case a hole dug into the
ground can cause steam to come to the surface. This type of
resource is rare in the US.
Geopressured Reservoirs: In this type of reserve, brine
completely saturated with natural gas in stored under pressure
from the weight of overlying rock. This type of resource can
be used for both heat and for natural gas.
Normal Geothermal Gradient: At any place on the
planet, there is a normal temperature gradient of +300C
per km dug into the earth. Therefore, if one digs 20,000
feet the temperature will be about 1900C above the surface
temperature. This difference will be enough to produce
electricity. However, no useful and economical
technology has been developed to extracted this large
source of energy.
Hot Dry Rock: This type of condition exists in 5% of
the US. It is similar to Normal Geothermal Gradient, but
the gradient is 400C/km dug underground.
Molten Magma: No technology exists to tap into the
heat reserves stored in magma. The best sources for this in
the US are in Alaska and Hawaii.
World Geothermal Provinces
Indian
Plate
Geothermal Energy Electricity Power Generation
Alternate Geothermal Technology – Power Tube
A short glimpse at
geothermal power
First experiment to produce geothermal power, done in Italy in 1904
by prince Ginori Conti
Photo courtesy of ENEL/ERGA, Italy
Photos: Lund
Modern geothermal power
plants in Larderello, Italy
A short glimpse at
geothermal power
Drilling rig at the
European R&D
site Soultz-sousForêts (F)
Principle of EGS
system for
geothermal
power production
Deep Geothermal Energy
Geothermal heating plant
Neustadt-Glewe photo O. Joswig
doublet system,
used since the late
1970s in France
and since 1984 in
(Eastern) Germany
• Present world-wide geothermal energy resources are constrained to
areas where hot springs, geysers, and volcanic activity produce
sufficient heat energy near the Earth’s surface for electric power
generation. These areas follow plate tectonic boundaries around the
world. Vast areas of the Earth lie sufficiently far from these
boundaries that they are generally untapped for geothermal electric
power production.
• A clean, renewable and environmentally benign energy source based
on the heat in the earth
• Used in 58 countries of the world. Known in over 80
• Electricity generation 53 TWh/a in 22 countries
• Direct heating use 53 TWh/a in 55 countries
• Geothermal is number three of the renewable energy sources in world
electrictity production after hydro and biomass. It is followed by wind
and solar energy
Iceland 200
Russia 23
Italy 762
Turkey 20
USA 2002
Japan 549
Azores 16
Mexico 858
Guatemala 33
El Salvador 161
Nicaragua 70
Costa Rica 143
China 29
Thailand 0.3
Guadeloupe 4
Ethiopia 9
Kenya 58
Philippines
1931
Indonesia 787
Australia 0.2
New Zealand 437
Geothermal electricity
Installed capacity MWe 2001
U.S. Geothermal Provinces
United States Geothermal Electric Power Generation Potential
(GeoPowering The West - DOE, 2000)
Top 3 States: Nevada, California, Utah
Other High Potential States: Idaho, Hawaii, New Mexico, Oregon,
South Dakota, Texas, and Wyoming
The basic requirements for an exploitable
DPSGE geothermal region are similar to
those for oil and gas exploration:
1) a sufficiently high geothermal gradient;
2) A significantly large, porous and
permeable reservoir to receive and heat
injection fluids;
3) A seal to contain the system.
Water temperature (optimum range)
230o to 380o F (110o to 193o C)
Construction costs ~ $1500 per kW
including exploration and drilling.
10 Mw plant $15,000,000
(National Renewable Energy Laboratory,
1999)
Geothermal Delivery Systems
Existing Plant Designs
Dry Steam Power Plants – use steam directly.
Flash Steam Power Plants – hot water under pressure
(most common).
Binary Cycle Power Plants – hot water through heat
exchanger.
Feedstock Systems – incremental heat in elevated water
temperatures.
New Plant Designs
Power Tube – iso-pentane & iso-butane into subsurface.
Direct uses of geothermal energy is
appropriate for sources below 1500C
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space heating
air conditioning
industrial processes
drying
Greenhouses
Aquaculture
hot water
resorts and pools
melting snow
Geothermal Greenhouses
Geothermal greenhouse
in Nigrita, Greece
Cultivation of spirulina
algae using geothermal
heat
How Direct Uses Work
•Direct Sources function by sending water 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 it is cooled is injected back into the
Earth.
The power tube housing resembles a giant hypodermic
needle. It has a modular nature, with the 10 megawatt unit
measuring about 4 feet across and around 180 feet in length.
Geothermal application in
the food industry
Geothermal tomato drying
in Northern Greece
The finished
product
Ground Heat Collectors
This system uses horizontal loops filled with circulating
water at a depth of 80 to 160 cm underground.
Borehole Heat Exchange
This type uses one or two underground vertical loops that extend 150
meters below the surface.
Generation of Electricity is
appropriate for sources >150oC
Dry Steam Plants: These were the first type of plants created. They use
underground steam to directly turn the turbines.
Flash Steam Plants: These are the most common plants. These systems pull deep, high
pressured hot water that reaches temperatures of 3600F or more to the surface. This water is
transported to low pressure chambers, and the resulting steam drives the turbines. The remaining
water and steam are then injected back into the source from which they were taken.
Binary Cycle Plants: This system passes moderately hot geothermal water
past a liquid, usually an organic fluid, that has a lower boiling point. The
resulting steam from the organic liquid drives the turbines. This process
does not produce any emissions and the water temperature needed for
the water is lower than that needed in the Flash Steam Plants (2500F –
3600F).
Casa Diablo
Geothermal application in
the food industry
Fish factory in Laugar, Iceland
Geothermal fish drying in
Northern Iceland
The finished product
Hot Dry Rocks: The simplest models
have one injection well and two
production wells. Pressurized cold
water is sent down the injection
well where the hot rocks heat the
water up. Then pressurized water
of temperatures greater than 2000F
is brought to the surface and passed
near a liquid with a lower boiling
temperature, such as an organic
liquid like butane. The ensuing
steam turns the turbines. Then, the
cool water is again injected to be
heated. This system does not
produce any emissions. US
geothermal industries are making
plans to commercialize this new
technology
Hot Rock
Geothermal Energy for the
German Parliament
Heat- and Cold Storage, heat source
waste heat from Combined Heatand Power-Generation (CHP) during
summertime
Shallow Geothermal Energy
Cooling
machines
refrigerators
freezers
Swimming pool
HX
Heat
pumps
(2 x 113 kW)
primary circuit
Geothermal heating at
the Polar Circle:
Hotel Storforsen, Älvsby,
Sweden
33 BHE each 160 m deep
HX
secondary circ.
HX
Recharge Cooling
(room air)
33 Borehole heat exchangers
each 160 m deep
E-boiler
HX:
Heat Exchanger
E-boiler: Electric heating
(peak/back-up)
TD:
Towel Drying
HW-St.: Hot Water Storage
HX
Floor
heating
warm tap
water
E-boiler
cold
tap water
HWSt.
DHW
TD
Geothermal energy in Iceland
Total Primary Energy
Consumption in 2002
• 86% of houses in the country
are heated by geothermal
• 17% of the electricity (200
MW) comes from geothermal
• Other uses include
greenhouses, fish farming,
industry, snow melting,
swimming pools etc.
• Only a fraction of the potential
is used
Thank you für your attention!
See you all in Blue Lagoon, Iceland
Direct uses for Geothermal water
Heating the alligator tank in Idaho – No swimming allowed
A boy bathes in Beaujolais
Nouveau at a Hakone Onsen
Yunessun hot springs resort
west of Tokyo in Japan. The
young French wine is released
on the third Thursday of
November every year.
Geothermal Harmful Effects
 Brine can salinate soil if the water is not injected back into
the reserve after the heat is extracted.
• Extracting large amounts of water can cause land
subsidence, and this can lead to an increase in seismic
activity. To prevent this the cooled water must be injected
back into the reserve in order to keep the water pressure
constant underground.
• Power plants that do not inject the cooled water back into
the ground can release Hydrogen Sulfide H2S, the “rotten
eggs” gas. This gas can cause problems if large quantities
escape because inhaling too much is fatal.
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Geothermal Energy - Positive Attributes
Useful minerals, such as zinc and silica, can be
extracted from underground water.
Geothermal energy is “homegrown.” This will
create jobs, a better global trading position and less
reliance on oil producing countries.
US geothermal companies have signed $6 billion
worth of contracts to build plants in foreign
countries in the past couple of years.
In large plants the cost is 4-8 cents per kilowatt hour.
This cost is almost competitive with conventional
energy sources.
•Geothermal plants can be online 100%-90% of the
time. Coal plants can only be online 75% of the time
and nuclear plants can only be online 65% of the time.
•Flash and Dry Steam Power Plants emit 1000 times to
2000 times less carbon dioxide than fossil fuel plants,
no nitrogen oxides and little SO2.
•Geothermal electric plants production in 13.380 g of
Carbon dioxide per kWh, whereas the CO2 emissions
are 453 g/kWh for natural gas, 906g g/kWh for oil and
1042 g/kWh for coal.
•Binary and Hot Dry Rock plants have no gaseous
emission at all.
•Geothermal plants do not require a lot of land, 400m2
can produce a gigawatt of energy over 30 years.
•Geothermal Heat Pumps:
- produces 4 times the energy that they consume.
-initially costs more to install, but its maintenance cost is 1/3 of the
cost for a typical conventional heating system and it decreases
electric bill. This means that geothermal space heating will save the
consumer money.
-can be installed with the help of special programs that offer low
interest rate loans.
•Electricity generated by geothermal plants saves 83.3 million barrels of fuel
each year from being burned world wide. This prevents 40.2 million tons of
CO2 from being emitted into the atmosphere.
•Direct use of geothermal energy prevents 103.6 million barrels of fuel each
year from being burned world wide. This stops 49.6 tons of CO2 from being
emitted into the atmosphere.
Availability of Geothermal Energy
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On average, the Earth emits 1/16
W/m2. However, this number can be
much higher in areas such as regions
near volcanoes, hot springs and
fumaroles.
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As a rough rule, 1 km3 of hot rock
cooled by 1000C will yield 30 MW of
electricity over thirty years.
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It is estimated that the world could
produce 600,000 EJ over 5 million
years.
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There is believed to be enough heat
radiating from the center of the Earth
to fulfill human energy demands for
the remainder of the biosphere’s
lifetime.