WHAT ARE THE MOST IMPORTANT CLEAN ENERGIES? - ENVIRONMENT - 2025

The clean energy are those that do not generate as much damage on Earth compared to fossil fuels such as coal or oil.

These fuels, also known as dirty energies, release greenhouse gases, mostly carbon dioxide (CO ₂), and have a negative impact on the planet's climatic conditions.

Unlike fuels, clean energies do not emit greenhouse gases, or they emit them in smaller quantities. This is why they do not pose a threat to the environment. In addition, they are renewable, which means that they resurface in a natural way almost as soon as they are used.

Therefore, non-polluting energies are necessary to protect the planet from the extreme weather conditions that it already presents. Similarly, the use of these sources will ensure the availability of energy in the future, since fossil fuels are not renewable.

It should be noted that obtaining non-polluting energy is a relatively new process, which is still under development, so it will take a few years until it becomes a real competition for fossil fuels.

However, nowadays, non-polluting energy sources have gained importance due to two aspects: the high cost of exploiting fossil fuels and the threat that their combustion poses to the environment. The best known clean energies are solar, wind and hydroelectric.

List with the most important clean energies

1- Solar energy

This type of energy is obtained through specialized technologies that capture photons from the sun (light energy particles).

The sun represents a reliable source since it can provide energy for millions of years. Current technology to capture this type of energy includes photovoltaic panels and solar collectors.

These panels directly transform energy into electricity, which means that there is no need for generators that could pollute the environment.

Technology used to obtain solar energy

a) Photovoltaic panels

Photovoltaic panels transform energy from the sun into electricity. The use of photovoltaic modules in the market has grown by 25% in recent years.

Currently, the cost of this technology is profitable in small devices, such as watches and calculators. It should be noted that in some countries this technology is already being implemented on a large scale. For example, in Mexico, around 20,000 photovoltaic systems have been installed in rural areas of the country.

b) Thermodynamic technology

Solar thermal energy comes from the heat generated by the sun. The technologies available in terms of thermal energy are responsible for collecting solar radiation and transforming it into heat energy. Subsequently, this energy is converted into electricity through a series of thermodynamic transformations.

c) Technology for the use of solar energy in buildings

Daytime lighting and heating systems are the most common solar technology used in buildings. Heating systems absorb solar energy and transfer it to a fluid matter, be it water or air.

More than two million solar water heaters have been installed in Japan. Israel, the United States, Kenya and China are other countries that have used similar systems.

With regard to lighting systems, these involve the use of natural light to illuminate a space. This is achieved through the inclusion of reflective panels in buildings (on roofs and windows).

Disadvantages of solar energy

• The cost of solar panels is still very high compared to other forms of available energy.
• Available technology cannot capture solar energy at night or when the sky is very cloudy.

Regarding the last disadvantage, some scientists are working on obtaining solar energy directly from space. This source has been named "space solar energy."

The basic idea is to place photovoltaic panels in space that will collect energy and send it back to Earth. In this way, the energy source would not only be continuous, but would also be clean and unlimited.

The aerospace engineer of the Naval Research Laboratory of the United States, Paul Jaffe, affirms that "if a solar panel is placed in space, it will receive light 24 hours a day, seven days a week, for 99% of the year".

The Sun shines much brighter in space, so these modules could receive up to 40 times the amount of energy that the same panel would generate on Earth.

However, sending the modules into space would be excessively expensive, which represents an obstacle to their development.

2- Wind energy

Over the years, the wind has been used to power sailboats and boats, mills or to generate pressure when pumping water. However, it was not until the 20th century that this element began to be thought of as a reliable source of energy.

Compared to solar energy, wind energy is one of the most reliable since the wind is consistent and, unlike the sun, it can be harnessed at night.

At first, the cost of this technology was excessively high, however, thanks to the advances made in recent years, this form of energy has become increasingly profitable; This is demonstrated by the fact that in 2014 more than 90 countries had wind energy installations, which supplied 3% of the total electricity consumed in the world.

Technology used to obtain wind energy

The technologies used in the field of wind energy, the turbines, are responsible for transforming the air masses that are in motion into energy. This can be used by mills or transformed into electricity through a generator. These turbines can be of two types: horizontal axis turbines and vertical axis turbines.

Disadvantages of wind energy

Despite being one of the least expensive non-polluting sources, wind energy has certain ecological disadvantages:

• Wind power towers interfere with the aesthetics of natural landscapes.
• The impact these mills and turbines could have on the habitat is uncertain.

3- Hydropower

This clean energy source obtains electricity through the movement of water. Water currents from rains or rivers are very useful.

Technology used to obtain hydroelectric energy

The facilities for obtaining this type of energy take advantage of the kinetic energy generated by the flow of water in order to generate electricity. In general, hydroelectric energy is obtained from rivers, streams, canals or dams.

Hydropower technology is one of the most advanced in terms of obtaining energy. In fact, approximately 15% of the electricity produced in the world comes from this type of energy.

Hydropower is much more reliable than solar power and wind power since, once dams have been filled with water, electricity can be produced at a constant rate. Furthermore, these dams are not only efficient but are also designed to be long-lasting and require little maintenance.

a) Tidal energy

Tidal energy is a subdivision of hydroelectric energy, which is based on obtaining energy through waves.

Like wind energy, this type of energy has been used since Ancient Roman and Medieval times, with wave-powered mills being very popular.

However, it was not until the 19th century that this energy began to be used for the production of electricity.

The first tidal power plant in the world is the Rance Tidal Power Station, which has been in operation since 1966 and is the largest in Europe and the second largest in the world.

Disadvantages of hydropower

• The construction of dams generates alterations in the natural course of rivers, affects the level of currents and affects the temperature of the water, which could have a negative impact on the ecosystem.
• If the size of these dams is excessive, they could generate earthquakes, soil erosion, landslides and other geological damage.
• They could also generate floods.
• From an economic point of view, the initial cost of building these dams is high. However, this will be rewarded in the future when they start working.
• If times of drought come and the dams are not full, electricity cannot be produced.

4- Geothermal energy

Geothermal energy is that obtained from the heat conserved inside the Earth. This type of energy can be collected at low cost only in areas with high levels of geothermal activities.

In countries like Indonesia and Iceland, for example, geothermal energy is accessible and could help reduce the use of fossil fuels. El Salvador, Kenya, Costa Rica, and Iceland are nations in which more than 15% of total electricity production comes from geothermal energy.

Disadvantages of geothermal energy

• The main disadvantage is economic: the cost of exploitation and excavation to obtain this type of energy is high.
• Because this type of energy is not as popular as the previous ones, there is a lack of qualified personnel to install the necessary technology.
• If not proceeded with caution, obtaining this type of energy could generate earthquakes.

5- Hydrothermal energy

Hydrothermal energy derives from hydroelectric and thermal energies and refers to hot water or water vapor that is trapped in the fractures of the earth's layers.

This type constitutes the only thermal energy that is exploited commercially at present. Facilities to harness this energy source have been built in the Philippines, Mexico, Italy, Japan and New Zealand. In California, United States, 6% of the electricity produced comes from this type of energy.

Biomass

Biomass refers to the transformation of organic matter into forms of usable energy. This type of energy can come from waste from agriculture, the food industry, among others.

Since ancient times, forms of biomass have been used, such as firewood; however, in recent years work has been done on methods that do not generate carbon dioxide.

An example of this is biofuels that can be used in oil and gas stations. Unlike fossil fuels, which are produced by geological processes, biofuels are generated through biological processes, such as anaerobic digestion.

Bioethanol is one of the most common biofuels; This is produced through the fermentation of carbohydrates from corn or sugar cane.

Burning biomass is much cleaner than burning fossil fuels, since the concentration of sulfur in biomass is lower. In addition, obtaining energy through biomass would make it possible to take advantage of materials that would otherwise be wasted.

In short, clean and renewable energies have the potential to provide significant amounts of energy. However, due to the high cost of the technology used to obtain electricity from these sources, it is clear that these types of energy will not yet completely replace fossil fuels.

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