Page 6 - Seaview Village

GEOTHERMAL ENERGY

Definition of Geothermal Energy:
Geothermal energy is heat extracted from the Earth’s interior. The term originates from 2 Greek
roots: the word geo which means “earth” and the word thermos which means “heat.”

How is geothermal energy obtained?
The temperature increases with depth in the Earth, a value called the geothermal gradient.
Beneath stable continents the gradient is ordinarily 30°C/km, however, in active tectonic areas
it can be as high as 100°C/km. Ground water circulating underground through the hot rocks is
heated. Very deep wells can be drilled to access the steam and water from these sources. In some
places there is molten rock, called magma, which is extremely hot. Once brought to the surface,
the energy can be used as heat or to generate electricity, or to heat buildings. Geothermal energy
also can come from shallow ground, although the temperature is the lower.

What is geothermal energy used for?
Geothermal energy is used for electricity generation. It is also used as a form of direct heat.

Brief History of Geothermal Energy
Many centuries ago, people began using the naturally heated water from the Earth for bathing.
Today, we convert the Earth’s naturally heated water into electricity.

Bathing Heating Electricity

Since Paleolithic times, During the first century At the beginning of the
geothermal energy has AD, Romans started 20th century, people
been used for bathing. using hot spring water experimented w/
People used natural to feed public bath geothermal power of
hot springs for warmth houses. During the 14th a source of electricity.
and cleansing. Minerals century, the commune In 1904, the first
in the water were of Chaudes-Aigues geothermal power
considered a source of in France—known as demonstration was
healing. Pictured above a spa town—started conducted at the
is the oldest known hot using hot spring water Larderello dry steam
spring pool. It was built not only to heat their field in Italy. By 1911,
in China during the 3rd spas but also to heat the world’s first power
century BC. their houses. geothermal power
plant was built there.
It would remain the
only industrial plant
until 1958 when New
Zealand built their first
plant.

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