geothermal energy @ india

7/31/2019 Geothermal Energy @ India

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What is Geothermal Energy?

The word geothermal comes from the Greek wordsgeo (Earth) and therme (heat). Geothermal energy is

heat from within the Earth.Geothermal energy is generated in the Earths core,almost 4,000 miles beneath the Earths surface. Thedouble-layered core is made up of very hot magma(melted rock) surrounding a solid iron center. Veryhigh temperatures are continuously produced insidethe Earth by the slow decay of radioactive particles.

This process is natural in all rocks.

Surrounding the outer core is the mantle, which isabout 1,800 miles thick and made of magma androck. The outermost layer of the Earth, the land thatforms the continents and ocean floors, is called thecrust. The crust is three to five miles thick under theoceans and 15 to 35 miles thick on the continents.

The crust is not a solid piece, like the shell of an egg,but is broken into pieces called plates. Magma comes

close to the Earths surface near the edges of theseplates. This is where volcanoes occur. The lava thaterupts from volcanoes is partly magma. Deepunderground, the rocks and water absorb the heatfrom this magma.

We can dig wells and pump the heated, undergroundwater to the surface. People around the world usegeothermal energy to heat their homes and to

produce electricity.Geothermal energy is called a renewable energysource because the water is replenished by rainfalland the heat is continuously produced deep within theEarth. We wont run out of geothermal ENERGY


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Finding Geothermal Energy

What are the characteristics of geothermal resources?

Some visible features of geothermal energy arevolcanoes, hot springs, geysers, and fumaroles. Butyou cannot see most geothermal resources. They aredeep underground. There may be no clues aboveground that a geothermal reservoir is present below.

Geologists use different methods to find geothermalreservoirs. The only way to be sure there is a reservoiris to drill a well and test the temperature deep

underground.The most active geothermal resources are usuallyfound along major plate boundaries whereearthquakes and volcanoes are concentrated. Most ofthe geothermal activity in the world occurs in an areacalled the Ring of Fire. This area borders the PacificOcean.

In India, exploration and study of geothermal fields started in 1970.The GSI (Geological Survey of India) has identified 350 geothermal

energy locations in the country. The most promising of these is in

Puga valley of Ladakh. The estimated potential for geothermal

energy in India is about 10000 MW.

ELECTRICAL ENERGY PRODUCTION

There are two types of the plants.

1. Flash steam plants

When the geothermal energy is available at 150 C and above

temperature, the fluids can be used directly to generate electricity. In

some cases, direct steam is available from the geothermal reservoir;

otherwise the steam is separated and turbines are used for power


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generation.

2. Binary plant

These plants are used when geothermal temperature is between 100

C and 150 C. The fluid is extracted and circulated through a heatexchanger where the heat is transferred to the low boiling point

organic liquid. This gets converted into high pressure vapour, which

drives organic fluid turbines

Hydrothermal Resources

There is more than one type of geothermal energy, but only one kind

is widely used to make electricity. It is called hydrothermal energy.

Hydrothermal resources have two common ingredients: water

(hydro) and heat (thermal). Depending on the temperature of thehydrothermal resource, the heat energy can either be used for

making electricity or for heating.

.Low Temperature Resources: HeatingHydrothermal resources at low temperatures (50 to300 degrees Fahrenheit) are located everywhere in

the United States, just a few feet below the ground.This low temperature geothermal energy is used forheating homes and buildings, growing crops, anddrying lumber, fruits, and vegetables.

In the U.S., geothermal heat pumps are used to heatand cool homes and public buildings. In fact,approximately 750,000 geothermal exchange systemsare installed in the U.S. Almost 90 percent of the

homes and businesses in Iceland use geothermalenergy for space heating.

High Temperature Resources: ElectricityHydrothermal resources at high temperatures (300 to700 degrees Fahrenheit) can be used to makeelectricity.


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These high-temperature resources may come fromeither dry steam wells or hot water wells. We can usethese resources by drilling wells into the Earth andpiping the steam or hot water to the surface.

Geothermal wells are one to two miles deep.In a dry steam power plant, the steam from thegeothermal reservoir is piped directly from a well to aturbine generator to make electricity. In a hot waterplant, some of the hot water is turned into steam. Thesteam powers a turbine generator just like a drysteam plant. When the steam cools, it condenses towater and is injected back into the ground to be used

over and over again.

Geothermal energy produces only a small percentageof U.S. electricity. Today, it produces about 15 billionkilowatt-hours, or less than one percent of theelectricity produced in this country

Geothermal Energy In India : Some Basic Facts

Our country is the one of the earliest country to begin with the

geothermal project in the early 1970s.

Indian geothermal provinces have the capacity to produce

10,600 MW of power

Locations in India.

Geological of India has identified 300 hot spring locations.

Some of the major locations identified by GSI are:

Puga valley in Jammu and Kashmir

Krishna Godavari basin

Tattapani geothermal area in Madhya Pradesh


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And lots more..

Puga Project

Located at laddakh one of the earlies found proviences in India,its isa place of research

1Himalayan Geothermal Province;

Located in extreme heat flow zone;

drill testing since 1970s.

picture discription

sured well, Puga Valley India(geothermal waters are at boiling temperature which isequivalent to 87C at this high altitude)

Applications could b done

Power generation

Cooking

Space heating

Use in greenhouse cultivationCrop drying

Pro/advantg

Geothermal energy requires no combustion; its energyalready exists as heat.1

Capital costs for geothermal installations are lower than forcomparable-size fossil- or nuclear-fueled plants, and once aplant is built, there are no fuel costs.2


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Where resources are abundant and accessible, geothermalpower is already an energy bargain, usually less expensivethan electricity generated by coal and nuclear plants.3

Geothermal energy is flexible in its applications. It is well-suited for integrated industrial use -- producing electricity,process steam, and heat for a a variety of industries andagricultural activities in a single region.4

There are no major economies of scale in production; smallgenerating modules can be added one at a time as localdevelopment and need dictate.5

con

Geothermal characteristics change with the area, soexploration is not easy.6

Geothermal turbine efficiency is comparatively low due to thelow temperature and pressure of steam input. Overall plantefficiency is estimated to be about 15 percent less than that ofa fossil-fueled plant.7

There is uncertainty about how long each geothermal well willlast.8

Possible environmental dangers posed by geothermal energyare:

land subsidence; production of waste water with high mineral content; disposal of hot water produced in the power conversion

process; release of noxious gases, such as hydrogen sulfide,

ammonia and boron into the atmosphere, and largeamounts of water vapor; and


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the amount of land taken up and noise produced aresubstantial.9

The use of geothermal heat must occur near the source; it

isn't possible to transport it very far.10

The geothermal energy supply is of low quality -- diffuse likesolar rather than concentrated like coal.11

Elkectrical facts

Electricity generated by geothermal plants saves 83.3million barrels of fuel each year from being burned world

wide. This prevents 40.2 million tons of CO2 from beingemitted into the atmosphere.

Direct use of geothermal energy prevents 103.6 millionbarrels of fuel each year from being burned world wide.This stops 49.6 tons of CO2 from being emitted into theatmosphere.


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geothermal energy @ india

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