Geothermal energy: advantages and disadvantages of its use

Its operation is based on how to manage the heat that accumulates underground. That heat is extracted using geothermal heat pumps to cool in summer, provide heat in winter, and supply hot water. Therefore, heat is either transferred or extracted from the earth depending on whether we want to obtain heating in winter or cooling in summer through a set of collectors buried underground through which a solution of water with glycol circulates.

Types of geothermal energy

Just as with other renewable energies such as wind energy and solar energy, there are several types of geothermal energy:

1. The hydrothermal areas, which contain water at high pressure and temperature stored beneath the earth's crust, in a permeable rock close to a heat source.
2. The hot rock systems formed by layers of impermeable rock covering a heat source.
3. The magma resources, which provide geothermal energy of very high temperature and whose natural manifestations are easily observed in geysers and hot springs.

Of these three types, the most used is hydrothermal resources due to the existence of drilling technology that makes it a source of viable energy with no high costs. At this time, the extraction of geothermal energy, like any other alternative energy, has its advantages and disadvantages.

Geothermal energy: advantages and disadvantages

Among its advantages are:

• Its cost is low and does not involve risks from its extraction.
• It can be obtained anywhere in the earth's crust, which would significantly reduce energy dependence from abroad in many countries.
• The waste it produces is minimal compared to that generated by other energy sources like oil and coal.

Its main disadvantages are:

• Although in small amounts relative to the energy supply it provides, it produces emissions of hydrogen sulfide and CO2.
• It can contaminate nearby waters with substances such as arsenic or ammonia.
• Its installation produces a significant visual impact on the landscape.
• It cannot be transported.

In order to improve its prospects as an alternative energy, the latest advances in the extraction of geothermal energy have to do with volcanoes and the supercritical water found in the hot rock in the subsurface where they are located. The latest drilling carried out in Iceland is very promising as it has reached depths of up to 4500 m., something unimaginable just a short while ago. This technique would bring many advantages to the geothermal energy we know today, significantly reducing waste generation and the impact on the landscape since the surface area required for extraction would be much smaller than currently used.