Advantages And Disadvantages Of Geothermal Energy
Geothermal energy is a renewable energy obtained from the heat stored inside the Earth. Thanks to the laws of thermodynamics, thermal energy is transferred from the interior of the Earth to a fluid. In this way, energy is transported in the form of internal energy.
Geothermal energy is basicaly based simply on taking advantage of the fact that the subsoil temperature is warmer than on the surface, in winter, and instead cooler, in summer. This is a consequence of the fact that the surface layers of the Earth are heated and cooled much more easily than the interior, which is maintained at a constant temperature throughout the seasons.
However, the use of geothermal energy implies some advantages and disadvantages that we analyze below.
Advantages of geothermal energy
In general, the advantages of geothermal are superior to the disadvantages. We list below the main advantages of geothermal energy.
- It is the most efficient energy of all renewable energies. The amount of thermal energy that is lost by transporting the heat from the bottom of the well to the surface is minimal.
- Geothermal energy remains stable throughout the different seasons of the year. Because the heat source is several meters underground, the thermal inertia is very high. The earth above has an insulating function that prevents thermal transmissions. The effect is similar to that of a cave in which the temperature is practically constant throughout the year.
- It is a source that can be found anywhere on Earth, unlike those that depend on deposits. However, there are more favorable sites than others. For example, in volcanic zones the temperature in the subsoil is easy to be much higher.
- It is independent of meteorological variations. It is an important difference regarding solar energy. It does not matter if it's cloudy, it rains or if the marshes related to hydraulic power are full or empty.
- It can be used in a particular way, for example in isolated houses where electricity does not arrive. In the case of single-family houses, by providing a constant temperature throughout the year close to 15º, geothermal energy can be used to cool the environment.
- Geothermal energy has the advantage that it does not require combustion of any material (neither uranium, nor fossil fuels like oil, coal or natural gas). Therefore it does not end with the reserves of this. This is the reason why it is considered a renewable energy.
- The waste produced is minimal and causes less environmental impact than those caused by combustion, nuclear or hydrocarbon energies. A typical single-family home stops emitting two tons of carbon dioxide per year if it uses geothermal energy compared to a house with a natural gas boiler.
- An important advantage is the ease of maintaining.
- Geothermal energy has high performance and low consumption.
- Economic savings. For example, in a house of about 150 to 180 square meters, the economic savings involved is 70%.
- The return time is very low. A geothermal energy installation is amortized between four and six years, this means that in this time, all the money saved in energy are equal to the price that it has been necessary to install the technology.
- The visual impact is minimal, as it is a remote installation. In the case of air conditioning is usually done with underfloor heating. No fans or interior appliances are needed in the rooms or outside, just one pump.
Disadvantages of geothermal energy
It is a new technology and less known than the other sources of energy. It is also difficult to calculate how many projects there are.
The main disadvantage of geothermal energy is precisely its own nature. It is necessary to extract it from the subsoil. For this reason, the first phases of the process are long and expensive. Impossibility to exploit this source of energy everywhere, we must first identify that the place is the ideal and the geological characteristics of the land. Geothermal energy is not viable in rocky terrain and unstable due to the difficulty of building wells.
It is more difficult to install in particular in large cities. The drawback of the cities is that the subsoil belongs to the town hall and is occupied by other services such as sewage pipelines gas and electricity, etc.
To carry out a project for a geothermal energy installation it is necessary to carry out previous studies. These studies require specific machinery and important investments in the initial phase of the project.
In addition, other disadvantages of geothermal energy are the following:
- Toxic emissions. In the event of an accident or leak, hydrogen sulfide can be released, which is detected by its odor of rotten eggs, but which is not perceived in large quantities and is lethal. In those cases there would also be some risk that toxic substances, such as arsenic, ammonia, etc., will be released and contaminate nearby waters.
- Environmental impact. To exploit this type of energy it is necessary to drill the earth's surface with the consequent deterioration of the landscape. This disadvantage is especially important in large geothermal installations, in single-family houses the environmental impact of geothermal energy is practically imperceptible.
- Local use only. It can not be transported as a primary source of heat, it must be consumed in the same place from which it comes. On the other hand, in geothermal power plants this problem disappears since electricity can be transported.
- Energía geotérmica: ventajas y desventajas - Energías renovables
- Energía geotérmica - Okdiario
- Low-Temperature and Co-produced Geothermal Resources - U.S. Department of Energy.
Last review: December 14, 2017