OBJECTIVES:
At the end of this topic, you shall be able to:
(1) Explain how heat from inside the earth is tapped as energy.
(2) Define geothermal energy.
(3) Illustrate the applications of geothermal power.
WHERE ARE GEOTHERMAL POWERPLANTS LOCATED?
Energy & Power Plants / By johnzactruba / Mechanical Engineering
As with any renewable energy source, availability at reasonable cost is the main criteria.
It is the same with geothermal energy. Since geothermal is tapping the underground thermal
reservoirs, nearness to the earth’s surface is an important criterion. Not all places on earth are
suitable for geothermal power plants. The current geothermal capacity is around 10,000 MW.
This is expected to more than double in the next few years.
WHERE ARE GEOTHERMAL POWERPLANTS CURRENTLY
USED?
The main countries that have large geothermal power plants are United States,
Philippines, Mexico, Italy and Indonesia. 85% of the present geothermal generation are in
countries that lie on the “Ring of Fire." Ring of Fire is the geographical locations on the Pacific
Rim that have high volcanic and earthquake activities. Significant generation outside of the
“Ring" are in Italy and Iceland. Italy was the pioneer in the use of geothermal resources with the
first geothermal plant starting in 1904. Iceland is one country that has the maximum percentage
of public power generation and heating from geothermal.
WHAT IS GEOTHERMAL ENERGY?
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is heat derived within the sub-surface of the earth.
can be used for heating purposes or be harnessed to generate clean electricity.
originates from the Greek roots (ge) meaning earth, and (thermos) meaning hot.
APPLICATIONS OF GEOTHERMAL ENERGY
(1) Generation of Electricity
(2) Spas
(3) Thermal Air-conditioning
(4) Hot spring Bathes
(5) District Heating and etc.
TYPES OF GEOTHERMAL POWER PLANTS
Three Basic Types Of Geothermal Power Plants:
1. Dry steam plants use steam directly from a geothermal reservoir to turn generator turbines.
The first geothermal power plant was built in 1904 in Tuscany, Italy, where natural steam
erupted from the earth.
2. Flash steam plants take high-pressure hot water from deep inside the earth and convert it to
steam to drive generator turbines. When the steam cools, it condenses to water and is injected
back into the ground to be used again. Most geothermal power plants are flash steam plants.
3. Binary cycle power plants transfer the heat from geothermal hot water to another liquid. The
heat causes the second liquid to turn to steam, which is used to drive a generator turbine.
TRIVIAL FACTS
1. Before, only Chinese maidens were allowed to bathe on hotsprings as signs of purity
and virginity.
2. Prince Piero Ginori Conti tested the first geothermal power generator.
3. In Iceland, people use geothermal heat pumps as airconditioner.
MORE INFORMATION:
 Thermal energy is the energy that determines the temperature of matter.
 Geothermal gradient is the difference in temperature between the core of the planet and
its surface.
 Parasitic load is normally a fraction of the heat output
 Earth's internal heat is thermal energy generated from radioactive decay.
 Lord Kelvin invented the heat pump in 1852.
 Geothermal Energy Association (GEA) installed geothermal capacity in the United
States.