What are the Most Important Clean Energies?

The clean energies Are those that do not generate as much damage on planet Earth as fossil fuels, such as coal or Petroleum .

These fuels, also known as dirty energies, greenhouse effect , carbon dioxide (CO ₂ ) In the majority, have a negative impact on the climatic conditions of the planet.

Unlike fuels, clean energies do not emit greenhouse gases, or emit them in smaller quantities. This is why they pose no threat to the environment. In addition, they are renewable, which means that they resurface naturally almost as soon as they are used.

Therefore, non-polluting energies are necessary to protect the planet from the extreme climatic conditions it already has. In the same way, the use of these sources will ensure the availability of energy in the future, because fossil fuels are not renewable.

It should be noted that the development of clean energy is a relatively new process, which is still under development, so it is still some years before it becomes a real competition for fossil fuels.

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

List with the most important clean energies

1- Solar energy

East Type of energy Is obtained through specialized technologies that capture photons from the sun (particles of light energy).

The sun represents a reliable source since it can provide energy for millions of years. The 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 25% during the last years.

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

B) Thermodynamic technology

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

C) Technology for the use of solar energy in buildings

Heating and daylight systems are the most common solar technology used in buildings. Heating systems absorb solar energy and transfer it to a flowing matter, either water or air.

In Japan, more than two million solar water heaters have been installed. 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 (in 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 can not capture solar energy at night or when the sky is overcast.

With regard to the latter 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 the space that will collect energy and send it back to Earth. In this way, the source of energy would not only be continuous, but would also be clean and unlimited.

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

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

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

2- Wind power

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

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

At first, the cost of this technology was excessively high; however, thanks to the progress 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 power facilities, which supplied 3% of the total electricity consumed in the world.

Technology used to obtain wind energy

The technologies used in wind energy, the turbines, are responsible for transforming the masses of air that are moving in 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 Disadvantages Of ecological type:

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

3- Hydroelectric power

This clean energy source gets electricity through the water movement. The water currents by the rains or the rivers are very useful.

Technology used to obtain hydropower

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

Technology in hydroelectric energy is one of the most advanced in terms of obtaining energy. In fact, about 15% of the electricity produced in the world comes from this type of energy.

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

A) Tidal power

The tidal power is a subdivision of hydroelectric energy, which is based on obtaining energy through the waves.

Like wind energy, this type of energy has been used since ancient times in Rome and the Middle Ages, with windmills being very popular.

However, it was not until the nineteenth century that this energy was used for the production of electricity.

The world's first tidal power plant is Rance's Marsomotor 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 causes alterations in the natural course of the rivers, affects the level of the 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, erosion in the terrain, landslides and other geological damages.
• They could also generate flooding.
• From an economic point of view, the initial cost of construction of these dams is high. However, this will be rewarded in the future when these begin to work.
• If droughts come and the dams are not full, electricity can not be produced.

4- Geothermal energy

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

In countries such as 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 where more than 15% of total electricity production comes from geothermal energy.

Disadvantages of geothermal energy

• The biggest disadvantage is economic: the cost of the exploitation and excavation to obtain this type of energy is high.
• Because this type of energy is not as popular as the previous ones, it lacks qualified personnel to install the necessary technology.
• If not proceeded with caution, the obtaining of 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 commercially exploited today. Facilities have been built in the Philippines, Mexico, Italy, Japan and New Zealand to harness this energy source. In California, the 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, from the food industry, among others.

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

An example of this are 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.

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

Biomass burning is much cleaner than fossil fuels, since the sulfur concentration in the 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, because of 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.

References

1. Haluzan, Ned (2010). Clean energy definition. Retrieved on March 2, 2017, from renewables-info.com.
2. Renewable energy and other alternative energy sources. Retrieved on March 2, 2017, from dmme.virginia.gov.
3. What are the different types of renewable energy? Retrieved on March 2, 2017, from phys.org.
4. Renewable energy supply. Retrieved on March 2, 2017, from unfccc.int.
5. 5 Types of Renewable Energy. Retrieved on March 2, 2017, from myenergygateway.org.
6. Scientists are working on new technology that could beam unlimited energy to Earth from space. Retrieved on March 2, 2017, from businessinsider.com.
7. Clean Energy Now and in the Future. Retrieved on March 2, 2017, from epa.gov.
8. Conclusions: Alternative energy. Retrieved on March 2, 2017, from ems.psu.edu.