Geothermal Energy
The Power From Below!
The words "geothermal energy" both come from the Greek language.
"Geothermal" is from two Greek words – "geo" meaning the earth and "therme" meaning heat.
"Energy" stems from the Greek word "ergon" - meaning work.
Literally translated, geothermal energy is "the work of earth's heat".
So
what is geo-energy and how does it work?
Follow the link for detailed information - simply stated however, geothermal power is derived from the earth's super-heated water and rock. We use this source of energy to produce practical power such as electricity.
It is an enormous, underused heat and power resource that is clean (emits little or no greenhouse gases) and reliable.
Geothermal resources range from shallow surface pools, to hot water and rock several miles below the Earth's surface, and even further down to the extremely hot molten rock called magma.
Mile-or-more-deep wells can be drilled into underground reservoirs and tap steam and very hot water that can then be brought to the surface for use in a variety of applications.
There are four types of geo-resources being:
* Hydrothermal resources.
* Geo-pressurized resources.
* Hot dry rock (HDR).
* Magma.
Hydrothermal resources are currently the only commercially viable type of geothermal power.
The hottest underground hydrothermal reservoirs are always in parts of the world where the seismic activity is greatest.
The seismic belt runs around the edge of the Pacific Ocean and is known as the “Pacific Ring of Fire”. Countries which lie along the belt include New Zealand, the Philippines, Japan, Russia and the western seaboards of North and South America.
In the U.S., most geothermal reservoirs are located in the western states, as well as Alaska and Hawaii.
Geothermal power plants
generate electricity from geothermal reservoirs. Deep wells are drilled into underground reservoirs to tap steam and very hot water. This is used to drive turbines which in turn drive electricity generators.
Almost everywhere, the upper 10 feet of Earth's surface maintains a near constant temperature of between 10 and 16°C (50 and 60°F).
This allows us another source of geo-energy which we use for heating and cooling.
Geothermal heat pumps consist of pipes buried in the shallow ground (near the building to be heated), a heat exchanger, and duct work into the building.
In winter, heat from the relatively warmer ground goes through the heat exchanger into the house.
In summer, hot air from the house is pulled through the heat exchanger into the relatively cooler ground.
Heat removed during the summer can be used as no-cost energy to heat water.
Unfortunately, geothermal sources provided less than 0.5 per cent of the world’s electricity in 2005 due to the fact that the practical application is still relatively costly.
In time, as costs of this relatively young energy come down, I am certain that geothermal power will become a widely utilized source of energy - particularly in residential applications.
For more detailed information on geothermal energy, click the text links and select from the topics below:
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