Geothermal Energy

Geothermal energy is another alternative source of energy. Geothermal energy is obtained from the internal heat of the earth. It is one of the oldest types of natural sources of heat. It dates back to Roman times, when the heat from the earth was used instead of fire, to heat rooms and warm water for baths.

Presently, it is being used as a source for producing electricity, mainly in regions of tectonic plate movement.

How do we get geothermal energy? Volcanic features around the world are called geothermal hotspots. Basically, a hotspot is an area of reduced thickness in the mantle which expects excess internal heat from the interior of the earth to the outer crust. These hotspots are well known for their unique effects seen on the earth’s surface, such as the volcanic islands, the mineral deposits and geysers (or hot springs).

The heat from these geothermal hotspots is altered in the form of steam which is used to run a steam turbine that can generate electricity.

Advantages of Geothermal Energy

Geothermal energy is used for heating homes and for generating electricity without producing any harmful emissions. Some of the advantages of using geothermal energy are:

  • Unlike most power stations, a geothermal power plant does not create any pollution. Harnessed correctly, it leads to no harmful by-products.
  • Geothermal Power plants have very low running costs. Because they require energy to run a water pump (which is provided by the power plant itself). Moreover, there are no costs for purchasing, transporting, or cleaning up of fuels.
  • Geothermal power plants are an excellent source of clean, and inexpensive renewable energy.
  • Geothermal energy can be used to produce electricity 24 hours a day.
  • Geothermal power plants are generally small and have little effect on the natural landscape, or the near environment.

Limitations of Geothermal Energy

Though geothermal energy has several advantages, it also has limitations:

  • If harnessed incorrectly, geothermal energy can produce pollutants.
  • Improper drilling into the earth can release hazardous minerals and gases.
  • Geothermal power plant sites are prone to running out of steam in the long run.

Interior of the Earth

The Earth can be divided into three large sections: the mantle, the inner core, and the outer core. The inner core is at the center of the earth. The pressure and temperature increase as one move closer to the center of the earth. As one moves outwards from the inner core, one encounters the outer core and then mantle followed by the crust.

The mantle is a layer that is below the crust of the earth. This is said to go down 2,900 km. Its temperature is about 870 degrees Celsius. The outer core has a very high temperature which ranges from about 4,400 degrees Celsius to about 6,100 degrees Celsius. The outer core begins where the mantle ends and it extends further down to the center 2,250 km.

The inner core is about 6,400 km below the earth’s surface. The temperature at the inner core of the earth is at the high of about 7,000 degrees Celsius. The high temperature of the earth’s core is the basic reason behind geothermal energy.