Geothermal energy is a type of energy that is pulled from the ground. “Geothermal” means the internal heat of the Earth. Deep in the base of the Earth are layers of hot water, hot rock and magma. Geothermal energy comes from these different layers of the Earth and can provide heat as well as cooling to a variety of different areas.
How it works and where it comes from
The Earth originated from a completely molten state. It’s believed that it would have cooled and become a completely solid rock many thousands of years ago if the only energy input was from that of the sun. Scientists believe that geothermal energy’s source is radioactive decay from deep within the earth.
There is, however, only a fraction of the thermal energy of the Earth that can be used. This is only in areas where water vapor can transfer heat to the surface of the Earth. A geothermal field in California, known as the Geysers, is the largest group of geothermal power plants in the world. The United States generates roughly 15 billion kilowatt hours of geothermal power per year. This is the equivalent of burning 25 million barrels of oil or six million tons of coal per year.
Currently, a major use of geothermal energy is to provide heat for commercial buildings. This is achieved by placing pipes under the business, which go down into the layers of the Earth. The heat, then, can be put to use for heating or cooling the buildings. However, the most common use of this type of energy is to produce electricity. There are [geothermal] wells that are used to drive a turbine that generates electricity.
As geothermal energy relies on something that occurs naturally in the Earth, there is very little cost involved with using it. The largest expense is the drilling and installation of the system. Also, a lot less energy is needed for the heating and cooling processes. The temperature increase or decrease that is needed is much lower than that of traditional methods used to heat or cool the air from outside to the temperature needed inside. This is because temperatures only need to be heated or cooled within 10 degrees. This means a much shorter time spent in waiting for this temperature change and a much lower expense involved in producing the desired temperature.
Despite large resources, geothermal continues to lag behind wind and solar energy projects
Geothermal energy has the largest potential in the western part of the United States. Geothermal plants are very site-specific and are limited to places that have highly accessible deposits of high temperature groundwater. Due to a lack of transmission lines in western states, there have been limitations on its growth. The other major hurdle is that completing a geothermal power-generating project takes anywhere from four to eight years, which is much longer than the completion timelines for solar or wind projects.
As technology progresses, it is expected that the turnaround time for a geothermal buildout will be reduced substantially. Once this is achieved, we will be able to better utilize one of the world’s cheapest and best kept secrets for renewable energy—the Earth itself.
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