Geothermal energy is what produces the internal heat of the Earth and has been concentrated in the subsoil,  in places known as geothermal reservoirs, which, if well managed, can produce clean energy indefinitely. Yes, Indefinitely

Check the following  video:  “What is geothermal?”

“What is Geothermal Energy?”

The earth’s crust is not flat.  it is divided into eight large plates and more than 20 smaller plates that with its movement  push each other slowly, at about 5 to 10 centimeters a year, which is about the same speed as your nails grow.

When the plates come together, one can slide under the other, allowing the generation of magma that can sometimes reach the surface generating volcanoes. In most cases, the magma does not go outside, but it is capable of heating large underground areas.

This heat source, magma, is one of the main elements of a geothermal system, but two more are needed to generate a reservoir: an aquifer and a seal. The aquifer is a permeable rock formation, that is, it allows water or other fluids to pass through it. And the seal is another layer of rocks, but waterproof. These three elements must be mounted one on top of the other, the heat source, on top of the aquifer and on top of them, the cover. It’s like a pressure cooker.

So, imagine this. It’s raining. The water slides along the earth’s surface and penetrates into the subsoil through faults and fractured rocks, which function as real pipes. The water is trapped in the aquifers, where it circulates and heats up, but it cannot go outside in its entirety, because it is covered by a layer of impermeable rock that prevents its passage. When these conditions occur, we are facing a geothermal reservoir.

Geysers and hot springs are some examples of what happens when some of this hot water or steam rises to the surface. As in our pot, it is possible that some of the steam escapes from the lid, although at much higher temperatures, above 150°C, and that makes them a huge source of energy.

In some cases, there are no natural water sources (such as rain or snow) to generate this circuit. In that case, the water can be injected artificially, and the phenomenon that will occur is the same.

Geothermal energy can be used directly to heat homes, temper greenhouses and fish farms, dehydrate vegetables, dry wood, among other applications.

This energy can also be used indirectly, to produce electricity. Generally, the force generated by the steam is used to drive a turbine capable of moving an electric generator, for instance.

Revisa video  “Los usos directos de la Geotermia”

In our planet there are places recognized for their great geothermal activity. The most extensive of them is the so-called “Pacific Ring of Fire”. This is a hughe  40,000-kilometer zone in the shape of an arc that crowns the ocean that gives it its name. Chile is one of the countries that is inserted in this circuit of fire, which place our country as a territory with great potential for the generation of geothermal energy.

Chile has more than 150 active volcanoes and an equal number of dormant volcanic centers that show geothermal activity. There are two main volcanic zones within the Chilean Andes: the North Volcanic Zone (17ºS – 28ºS) and the Center-South Volcanic Zone (33ºS – 46ºS). Today, the Andean Chain represents one of the largest untapped geothermal provinces in the world.

Geothermal energy has been used on a large scale since the beginning of the 20th century in Italy, and mainly in volcanic areas such as Iceland, the Philippines, New Zealand and some regions of California.

In Latin America, geothermal energy has also begun to be explored as a reliable source of energy. To learn more about the projects in the region and their progress, you can check this World Bank site.

Banco Mundial.

The first stage is Exploration, which can be carried out in territories granted by the Ministry of Energy. During this stage, experts visit the area to take samples (water, temperature, rocks, and minerals) to characterize the resource and locate the exploratory wells.

The second stage is Exploratory drilling, where drilling is carried out to depth (approximately 2,000 m) to determine if the geothermal resource at that location is of commercial importance.

Then it goes to an Evaluation and Confirmation stage, where the size of the resource and the feasibility of its economic development will be determined.

If the results of the previous stage are positive, the Development stage follows, which will consist of the construction of the power plant, transmission lines, surface pipelines, production facilities and well drilling. Subsequently, in the Operation stage, the generation of electricity will soon be produced.

Geothermal energy has been used on a large scale since the beginning of the 20th century in Italy, and mainly in volcanic areas such as Iceland, the Philippines, New Zealand and some regions of California (USA), where classical geothermal systems use the natural water that circulates near hot volcanic chambers or similar bodies.

Chile’s location in the so-called “Pacific Ring of Fire” makes it one of the regions with the highest volcanic activity in the world, which logically implies great potential for generating geothermal energy in our country.

Thermal waters correspond to surface emissions of warm to hot water with compositions rich in salts and dissolved gases. These thermal emissions are the result of groundwater heating by: (a) proximity effects with an anomalous heat source, in other words,  rocks heated by subsurface magma, or (b) geothermal gradient effect, which is the warming of groundwater that occurs as we go deeper into the earth’s crust.

Geothermal exploitation does not affect tourism and/or recreational hot springs if it is carried out in a sustainable manner.

Modern geothermal plants use the hot water extracted from geothermal wells in combined cycles to generate steam and drive electricity generation turbines. The extracted water is re-injected into the geothermal reservoir, thus maintaining the hydrological balance.

The closest volcano to Santiago is Tupungatito (5,640 m high), about 75 km east of the capital. It is followed by the San José volcanic complex (5,880 m) 80 km south east of Santiago and next to it, the Marmolejo volcano (6,109 m). A little further down is the Maipo (5,290 m) 110 km from the city. In the surroundings of Santiago there are no geyser-type thermal manifestations.

Both, geysers and volcanoes depends on the presence of a heat source deep on earth. However, the eruption mechanisms are different. Geysers are very rare and superficial singularities, where groundwater is heated to the point of boiling, which produces a violent emission of liquid water and water vapor.

After the eruption of the geyser, which can be periodic or sporadic, a new cycle begins as a result of the entry of cold water that begins its gradual heating process.

Geysers, therefore, do not need to be associated with a volcano, but they do occur in regions where there is intense volcanic activity.

The reason for the larger size of the geysers at dawn, is more apparent than real, and is related to the low temperatures that exist between 4 and 7 AM, which produce greater condensation of the steam emitted by the geysers.

This effect translates into a greater perception of the steam emitted by the geyser, just like when we expel the air from our lungs on the coldest mornings of the year