Download Geothermal energy

GEOTHERMAL ENERGY
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Geothermal energy is the heat that lies within the Earth. This heat energy is obtained from
hot rocks present inside the Earth.
The word ‘geothermal’ comes from the Greek words ‘geo’ (Earth) and ‘therme’ (heat).
Almost 4000 miles beneath the Earth’s surface, this phenomenon known as geothermal
energy gets generated, deep inside the Earth’s core.
The outer core is made up of very hot magma (melted rock) surrounding a solid iron center
which is the inner core.
Surrounding the outer core is the mantle. About 1800 miles thick, it is made of magma and
rock. The outermost layer of the Earth is the crust.
The Earth’s crust is broken into several pieces called plates. Magma comes close to the
Earth’s surface near the edges of these plates.
Deep underground, the rocks and water absorb the heat from this magma. The temperature
of the underground rocks and water increases with increasing depth.
Geothermal Energy Is Generated Deep Inside the Earth
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People around the world use this underground energy to heat their homes and to produce
electricity by digging deep wells and pumping the hot underground water or steam to the
surface.
Since ancient times, geothermal energy has been used for heating and bathing.
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The Italians first used the natural steam erupting from the Earth to power a turbine
generator.
The first successful American geothermal plant began operating in 1960 at The Geysers in
northern California. Most of American geothermal power plants are in California with the
remaining in Nevada, Hawaii, Idaho, Montana and Utah.
Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs.
The only way to be sure that there is a reservoir is to drill a well and test the temperature
deep underground.
Geothermal energy sometimes funds its way to the surface in the form of volcanoes and
fumaroles, hot springs and geysers.
Volcanoes and fumaroles (holes where volcanic gases are released)
Hot springs
Geysers
Most geothermal activities work occur along the borders of the Pacific Ocean called the Ring
of Fire.
 Where Geothermal Energy is Found
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The heat energy produced mainly using water (hydro) and the heat (thermal) is called
hydrothermal energy.
Depending on the temperature of the hydrothermal resource, the heat energy can be used
for heating, making electricity or as heat pumps.
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Ancient Romans, Chinese and Native American cultures used hot mineral springs for bathing,
cooking and heating. Many hot springs are still used for bathing for its natural healing
powers.
Hot water from springs or reservoirs near the surface is used for heating buildings. Industries
use geothermal energy for food dehydration, gold mining, milk pasteurization and growing
crops.
Hydrothermal resources at high temperatures (300 to 700 degrees Fahrenheit) can be used
to make electricity.
Geothermal heat pumps use stable ground or water temperatures near the Earth’s surface
to control building temperatures above the ground.
Unlike solar, wind or tidal energy, geothermal energy can operate round the clock. This
source of energy is free and renewable.
Geothermal plants produce almost no emissions because they do not burn fuel to generate
electricity. Its operating costs are also quite low.
Another advantage is that geothermal plants don’t have to transport fuel, like most power
plants.
Not all areas are suitable for production of electricity in this way and is also depends on the
structure of rocks.
Generation of geothermal energy creates noise pollution and releases noxious smells. Even
through operating costs are low, cost of setting up a geothermal plant is high.
In some places, hot water come naturally to the surface as steam which can drive turbines to
generate electricity. Some power stations make use of lava that flows from the volcanoes.
In India, there are about 400 hot springs that can be tapped for geothermal energy.
Despite a few disadvantages, it is an undeniable fact that, geothermal energy is an extremely
valuable, simple and clean source of energy that can benefit mankind in a big way.
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