Geothermal Energy

Geothermal Energy

By Claudine Francisco

Geothermal Energy

It is a type of renewable energy source derived from the heat deep in the earth's crust.

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The heat of the Earth warms up water which is trapped in rock formations beneath its surface.​

The production of electricity from geothermal energy is cheaper than the electricity production using natural gas, coal, and hydropower.

According to the Department of Energy, 14.4% of the country’s total power of generation is produced from the geothermal energy.

Geothermal Energy

Three Types of Geothermal Power Plants

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Dry Steam Power Plant

• ​Most common types of geothermal power plants

• They work by piping hot steam from underground reservoirs directly into turbines from geothermal reservoirs, which power the generators to provide electricity.

• After powering the turbines, the steam condenses into water and is piped back into the earth via the injection well.

Flash Steam Power Plant

• They pump hot water, rather than steam, directly to the surface.

• These flash steam plants pump hot water at a high pressure from below the earth into a “flash tank” on the surface. The flash tank is at a much lower temperature, causing the fluid to quickly “flash” into steam.

• The steam produced powers the turbines. The steam is cooled and condenses into water, where it is pumped back into the ground through the injection well.

Binary Cycle Power Plant

• The water or steam from below the earth never comes in direct contact with the turbines. Instead, water from geothermal reservoirs is pumped through a heat exchanger where it heats a second liquid—like isobutene (which boils at a lower temperature than water.)

• This second liquid is heated into steam, which powers the turbines that drive a generator.

• The hot water from the earth is recycled into the earth through the injection well, and the second liquid is recycled through the turbine and back into the heat exchanger where it can be used again

Study and memorize the following:

Advantages and Disadvantages of Geothermal Power Plant