Part VIII: Geothermal

Part VIII: Geothermal looks at one of the oldest forms of energy on this planet. Geothermal heat sources are used in a variety of ways across our world today, from geothermal power plants, to geothermal hot water systems, we shall now attempt to understand what this geothermal energy is, and where it comes from. Thanks to Wikipedia, EERE of the Department of Energy, and clean-energy.com.
What geothermal energy is, can essentially be described with the sentence; heat contained and produced by the heating of the earth in two different ways. The more powerful geothermal energy comes from deep within the earth, where the temperature is hot enough to melt the surrounding rocks. The second source of geothermal energy is as a results of the suns rays beating down on the land surface. We shall now look into these two main sources.
The center of the earth is approximately 4000 degrees Celsius, as described in the above sentence, this tremendous amount of heat is capable of turning rocks into liquid. This heat is able to warm the earth right up to surface. The reason you do not burn your feet when they touch the ground is because there is a great distance between our feet and this molten rock, and only a very small, but significant fraction of this heat is transferred to the surface.
You may find molten rock very close to surface along fault lines and around volcanoes, and this enables a volcanic area to be a very significant source of geothermal power. So we have now discovered the most powerful source of geothermal energy comes from the core of the earth, and if you are planning to harness geothermal energy, you are best doing so where molten rock is closest to the surface.
The history of geothermal power can be traced back to over 10,000 years ago to the American Paleo-Indians at their settlement in hot springs. This history has been uncovered through the use of archeology and shows the Indians used the hot springs for activities including, bathing and heating. It is also believed the springs were seen as a healing source.
It is believed that the first geothermal energy use in industry was during the late 18th century near Pisa, Italy. This history of geothermal shows energy been used to extract boric acid from the Larderello Fields through the use of steam.
A history of the first geothermal power plant relates to the Larderello Fields, when in 1904 the steam was successfully used to generate power for the first time. This geothermal energy was seen as the power of the future.
More history: In 1922 the U.S.A's first geothermal power plant went down in history in producing 250 kilowatts which could light the streets and buildings in the area. This plant didn't last very long however, due to the little power output compared to other sites across the globe.
During the 1960's, the first large scale industrial geothermal energy power plant was constructed in the U.S.A and produces 11 megawatts of environmentally friendly, renewable, geothermal electricity. This was seen as a big step towards power of the future.
From the 1960's onwards, many organizations and governing bodies are set up to manage, research, and develop new and improved geothermal energy sites and technologies.
Today, there are more than 60 important geothermal power plants, in working order in the U.S.A, and many more across the globe. The history of geothermal power is just the very basis of what we can expect from the future. The geothermal energy and power advancements of the past can show how through this geothermal history, we can predict, newer and much greater capacity power stations could be developed in the future.
The second source is more commonly overlooked as an alternative to the earths geothermal heat source, yet this method is installed in a significant amount of homes in areas such as Iceland, Norway, and Sweden, and is becoming more popular in the U.K.
The great advantage of the suns geothermal effect, is you are able to harness the power in most areas unlike the earths geothermal heat source, where the location of, lets say a geothermal power plant can be the deciding factor in it's efficiency. So, geothermal energy from the sun is essentially a solar energy idea, in that the original source of "ground source heat energy" is from the sun.
All through the day, the suns rays shine down on the earths surface, and this heats the first couple of meters of our earth quite significantly. To understand this more, think about when it's been snowing, and sun then comes out. Do you notice how there is always snow left in shaded areas a long time after the rest of the snow has melted? This isn't to do with the general temperature increasing, it is the heat contained within the suns rays. This shows you how powerful our sun is, in that it is able to melt snow on our surface.
A very good, proven method of extracting this geothermal energy from the sun is though the use of geothermal heat pumps, which enable a low cost hot water heating system that is very environmentally friendly for your home.

Tomorrow we will look at Natural Gas, in Part IX of the energy series. Thanks and Have A Great Day!!

link to eere geothermal