Geothermal energy is one of the most interesting and promising renewable resources thanks to its ability to harness the Earth's internal heat. Its potential to improve energy supply conditions in various sectors makes it one of the most attractive renewable technologies for the future. Below, we will delve into what geothermal energy is, how it works, its history, applications, advantages and disadvantages, and its situation in Spain.
What is geothermal energy?
Geothermal energy It is defined as a renewable energy source that uses the heat from the Earth's subsoil. This heat is generated inside the Earth and comes to the surface in geological phenomena such as volcanoes, geysers and hot springs. However, this heat can not only be used in these phenomena. It is also possible through the installation of subsoil heat extraction systems, such as geothermal heat pumps, which allow their use for heating, cooling and even electricity generation.
When we talk about low enthalpy geothermal energy, we are referring to that which is found at a shallower depth, while high enthalpy resources can be found kilometers deep.
Geothermal energy has proven to be a reliable, consistent and long-term option, as it is capable of generating energy without depending on seasonal fluctuations as is the case with solar or wind energy. However, its geographical distribution is conditioned by the availability of deposits of heat in favorable areas.
History of geothermal energy
The history of geothermal energy in Europe began with Sweden as a pioneer, driven by the oil crisis in 1979. The need for alternative energy sources led many countries to take advantage of this renewable source. Finland, the United States, Japan, Germany, France and the Netherlands have also developed significant capacities in this field for decades.
Iceland is one of the countries that has made the most progress in this field worldwide, taking advantage of its high-temperature volcanic resources for the production of electricity and heating of buildings. Recently, in South America, Chile has inaugurated the first geothermal plant on the continent, which demonstrates the growing interest in this technology in other regions.
Geothermal energy applications
The applications of geothermal energy are varied and depend on the temperature of the available geothermal resources:
- Electricity production: High enthalpy resources (>150 °C) are ideal for generating electricity using steam turbines.
- Heat pumping systems: Low enthalpy resources (30-150 °C) are used to heat buildings such as homes, offices, or even greenhouses and aquaculture ponds. These types of applications are increasingly being developed in countries such as the United States, Japan and parts of Europe.
- Industry and agriculture: Industries require thermal energy for processes such as drying, chemical extraction, pasteurization and greenhouse heating, making geothermal a valuable resource.
- District heating: Some countries such as Iceland use geothermal energy to provide heating to entire districts through centralized systems, reducing dependence on fossil fuels.
Advantages of geothermal energy
Geothermal energy has numerous advantages:
- Local and free source: Geothermal energy is not dependent on imports and is constantly available in countries with suitable deposits.
- Respectful with the environment: Geothermal energy generation produces very few greenhouse gas emissions, making it a clean energy source.
- Potential for job creation: Geothermal energy installations create a demand for skilled workers in engineering, drilling and other technical areas.
- Stable long-term cost: Unlike non-renewable energy sources, geothermal energy is not subject to fluctuations in fuel prices, ensuring stability in generation costs.
Disadvantages of geothermal energy
Despite its many benefits, geothermal energy also has some drawbacks that need to be addressed:
- Performance limited to place of origin: Facilities must be close to the deposits, which limits their distribution and access to remote urban areas.
- High initial investment: The infrastructure for the exploitation of geothermal deposits requires significant investment, both in exploration and in drilling and plant construction.
- Degradation of deposits: Excessive exploitation of a deposit can deplete the resource if there is no adequate control over its regeneration capacity.
- Earthquake risk: In rare cases, geothermal operations can trigger earthquakes due to changes in pressure underground.
Geothermal energy in Spain
In the case of Spain, the use of geothermal energy is still very limited compared to other European countries. Although significant potential has been detected in some areas, such as the Canary Islands Due to its volcanic origin, the lack of investment and adequate policies has prevented the development of this technology in the country.
However, there is some encouraging news: Galicia could become one of the first regions to use geothermal energy for heating, air conditioning and hot water in buildings. In addition, growing interest in geothermal heat pumps is driving demand in the residential sector.
Although the development of large-scale projects for electricity generation is not viable in many areas of Spain, its use in smaller applications, such as heating systems, is expanding, helped by economic and technological incentives.
Global perspective and relevant projects
Globally, the use of geothermal energy is expanding significantly in regions with high potential, such as Iceland, New Zealand and parts of Central America. Chile, for example, recently opened the first geothermal power plant in South America, capable of generating energy for more than 165.000 families.
These types of projects stand out for their ability to generate clean energy, taking advantage of the Earth's natural resources without causing a significant environmental impact. In fact, geothermal energy is one of the renewable energy sources with the lowest carbon footprint.
Despite some challenges related to geography and initial investment, geothermal energy is seen as a viable solution to reduce dependence on fossil fuels. Compared to other renewable energy sources such as solar or wind, it has the advantage of being constant and not dependent on climatic factors.
In our country, there is still a long way to go to achieve mass implementation, but with the right policies, the use of this energy source could grow considerably in the coming years.