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8/4/2019 MEGHRAJ Presentation

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GEOTHERMAL ENERGY

By

G.M.MEGHRAJ4NM08ME036 by- MEGHRAJ

4nm08me036



CONTENTS

•INTRODUCTION

•HOW IS ELECTRICITY GENERATED USING

GEOTHERMAL ENERGY?

•DIRECT APPLICATION

•ENVIRONMENTAL IMPACT

•ECONOMICS

•RESOURCES

•

PACIFIC RING OF FIRE•HISTORY

•ADVANTAGES AND DISADVANTAGES

•CONCLUSION



INTRODUCTION :

• Geothermal energy (from the Greek roots geo, meaning earth,

and thermos, meaning heat) is power extracted from heat stored

in the earth.

• This geothermal energy originates from the original formation

of the planet, from radioactive decay of minerals, from volcanicactivity and from solar energy absorbed at the surface.

• Geothermal power has the potential to help mitigate global

warming if widely deployed in place of fossil fuels.



HOW IS ELECTRICITY GENERATED USING

GEOTHERMAL ENERGY?

•

In geothermal power plants steam, heat or hot water fromgeothermal reservoirs provides the force that spins the turbine

generators and produces electricity.

• There are three kinds of geothermal power plants. The kind we

build depends on the temperatures and pressures of a reservoir.

• A "dry'" steam reservoir produces steam but very little water. Thesteam is piped directly into a "dry" steam power plant to provide

the force to spin the turbine generator.

• A geothermal reservoir that produces mostly hot water is called a

"hot water reservoir" and is used in a "flash" power plant. Waterranging in temperature from 300 - 700 degrees F.

• A reservoir with temperatures between 250 - 360 degrees F is not

hot enough to flash enough steam but can still be used to produce

electricity in a "binary" power plant.



Direct application:

• In the geothermal industry, low temperature means temperaturesof 300 °F (149 °C) or less. Low-temperature geothermal resourcesare typically used in direct-use applications, such as districtheating, greenhouses, fisheries, mineral recovery, and industrialprocess heating.

• Heat pumps for home heating are the fastest-growing means of exploiting geothermal energy.

• Direct heating is far more efficient than electricity generation andplaces less demanding temperature requirements on the heatresource.

• District heating applications use networks of piped hot water toheat many buildings across entire communities.In Iceland, spentwater from the district heating system is piped below pavementand sidewalks to melt snow.



Environmental impact:

• Fluids drawn from the deep earth carry a mixture of gases, notably

carbon dioxide (CO2), hydrogen sulphide (H2S), methane (CH4) andammonia (NH3). These pollutants contribute to global warming, acid

rain, and noxious smells if released.

• Plants that experience high levels of acids and volatile chemicals are

usually equipped with emission-control systems to reduce the

exhaust.

• In addition to dissolved gases, hot water from geothermal sources

may hold in solution trace amounts of toxic chemicals such as

mercury, arsenic, boron, and antimony.

•Plant construction can adversely affect land stability.

• Enhanced geothermal systems can trigger earthquakes.



Economics

• Geothermal power requires no fuel (except for pumps), and is

therefore immune to fuel cost fluctuations, but capital costs are

significant.

• Drilling accounts for over half the costs, and exploration of deep

resources entails significant risks.• Direct heating applications can use much shallower wells with

lower temperatures, so smaller systems with lower costs and risks

are feasible.

•

Residential geothermal heat pumps with a capacity of 10 kilowatt(kW) are routinely installed for around $1 – 3,000 per kilowatt.

• Geothermal power is highly scalable: from a rural village to an

entire city.



Resources

• Enhanced geothermal

system -1:Reservoir

2:Pump house

3:Heat exchanger

4:Turbine hall5:Production well

6:Injection well 7:Hot water

to district heating

8:Porous sediments9:Observation well

10:Crystalline bedrock

http://en.wikipedia.org/wiki/File:EGS_diagram.svg



Continued...

• The Earth's internal heat naturally flows to the surface byconduction at a rate of 44.2 TW and is replenished by radioactivedecay of minerals at a rate of 30 TW.

• In addition to heat emanating from deep within the Earth, the top10 meters (33 ft) of the ground accumulates solar energy (warmsup) during the summer, and releases that energy (cools down)during the winter.

• Beneath the seasonal variations, the geothermal gradient of temperatures through the crust is 25 – 30 °C (77 – 86 °F) perkilometre of depth in most of the world.

• A geothermal heat pump can extract enough heat from shallowground anywhere in the world to provide home heating, butindustrial applications need the higher temperatures of deepresources.



Pacific Ring of Fire:

http://en.wikipedia.org/wiki/File:Pacific_Ring_of_Fire.svg



• The Pacific Ring of Fire (or sometimes just the Ring of Fire) is an

area where large numbers of earthquakes and volcanic eruptions

occur in the basin of the Pacific Ocean.

• In a 40,000 km (25,000 mi) horseshoe shape, it is associated witha nearly continuous series of volcanic arcs, and volcanic belts

and/or plate movements.

• The Ring of Fire has 452 volcanoes and is home to over 75% of

the world's active and dormant volcanoes. It is sometimes calledthe circum-Pacific belt or the circum-Pacific seismic belt.

• The Ring of Fire is a direct result of movement and collisions of

crustal plates.



















History:

• The oldest known pool fed by a hot spring, built in the Qin

dynasty in the 3rd century BC.

• Hot springs have been used for bathing at least since.

• Romans conquered Aquae Sulis, now Bath, Somerset, England,

and used the hot springs there to feed public baths andunderfloor heating. The admission fees for these baths probably

represent the first commercial use of geothermal power.

• In the 20th century, demand for electricity led to the

consideration of geothermal power as a generating source.Prince Piero Ignore Conti tested the first geothermal power

generator on 4 July 1904.




















Advantages of Geothermal energy:

• A geothermal system does not create any pollution.

• The cost of the land to build a geothermal power plant on, is

usually less expensive than if you were planning to construct an;

oil, gas, coal, or nuclear power plant.

• No fuel is used to generate the power, which in return, means therunning costs for the plants are very low.

• The overall financial aspect of these plants is outstanding; you

only need to provide power to the water pumps, which can be

generated by the power plant itself anyway.


















Disadvantages:

• Greenhouse gas emissions: Geothermal electric plants emit an

average of 122 kg of CO² per megawatt-hour (MW·h) of electricity.

• Toxic chemical emissions: Hot water from geothermal sources will

contain trace amounts of dangerous elements such as mercury,

boron, arsenic, antimony, etc.

• Localized Depletion: The 3 oldest Geothermal sites have beenexperiencing what is known as "Localized Depletion" of Heat and

Water.

• Geological instability: The project in Basel, Switzerland was

suspended because more than 10,000 seismic events over the first 6

days of water injection.

• Cost/Hazard: Drilling accounts for over half the costs, and

exploration of deep resources entails significant risks.

• A 20% failure rate.

























CONCLUSION:

• It is Globally Sustainable.

• Still safer than Fossil Fuels.

• Geothermal heating is flame-less, therefore producing no health

and safety concerns as associated with fossil fuels.

• Geothermal energy is sustainable because hot water can be re-

injected into the ground.

• Geothermal energy is extremely price competitive in suitable

areas.


















THANK YOU



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