Geothermal energy harnesses the heat from the Earth's interior.
Geothermal energy is energy obtained by harnessing heat from the Earth 's interior. This heat can be generated by different factors.
Before moving forward, it is important to point out that energy can be understood as a natural resource that, thanks to certain associated elements, can be used industrially. The concept also refers to the ability to set something in motion or transform something.
Geothermal , on the other hand, is a term that comes from the Greek language and is composed of two words: geo ( "Earth" ) and thermos ( "heat" ), that is, "heat of the Earth."
Characteristics of geothermal energy
Geothermal energy can be used to extract steam from shallow hot springs . Another source of geothermal energy is magma (a mixture of molten rock and gases), although there are not enough technological resources for its industrial exploitation .
Typically, geothermal power plants operate with at least two wells: one is used to obtain hot water, while the other is used to reinject the cooled water back into the aquifer. This system makes it possible to maintain the water flow from the reservoir.
It should be noted that geothermal deposits can be depleted and/or cooled, which means that this type of energy is not completely renewable.
Geysers are a source of geothermal energy.
Its use
Although geothermal energy is one of the least known types of renewable energy by people outside the scientific field, it is very likely that we have all seen the effects of this natural source of heat in action more than once in our lives; some of the examples of its manifestation are volcanic eruptions , geysers , fumaroles (cracks in the earth that allow the escape of water vapor and sulfurous gases coming from a volcanic conduit) and hot springs (known especially for the relaxation they produce when they come into contact with the body).
In Europe , the first country to take advantage of it was Sweden , following the oil crisis in 1979 ; other parts of the world where this energy has been widely exploited for a long time are Japan , France , Holland and Finland .
Types of geothermal energy
It is possible to distinguish between very low temperature geothermal energy (used for agriculture or in residential areas), low temperature geothermal energy (with fluids between 50º and 70º), medium temperature geothermal energy (between 70º and 150º) and high temperature geothermal energy (between 150º and 400º).
Geothermal energy is very efficient and clean, and has many applications. High-temperature resources are especially useful for producing electricity . If the temperature is not sufficient for this purpose, it is used to provide air conditioning (both heating and cooling) in residential, service or industrial sectors, using a geothermal heat pump . Finally, in the case of very low temperatures, they are used both for air conditioning and for providing hot water.
It is worth mentioning that geothermal energy with very low temperatures is found very close to the Earth's surface; in some countries it is enough to descend 10 meters to find 17 degrees Celsius at any time of the year, given the thermal inertia of the ground .
One of the devices used to harvest geothermal energy is a series of panels buried underground, through which a solution containing water and glycol is circulated, allowing heat to be released or extracted from the earth to meet heating or cooling needs . Some cities have very ambitious plans to take advantage of this type of renewable energy; Madrid , for example, plans to supply the air conditioning of its entire metro network with it.