Renewable and non-renewable energies: examples and summary

When we talk about renewable energies, we refer to those energies from natural and almost inexhaustible sources, either because of the amount of energy they contain or because of their ability to regenerate naturally. We say “almost” because these energy sources are subject to a renewal period, so their exploitation must respect these periods so that they truly function as unlimited energy sources .

This type of energy was considered as alternative energy in the 1970s. However, it is currently still more expensive than conventional energy. Another drawback is that in order to take advantage of these energy sources, very large spaces are needed, and for this reason the possibility of having these extensive lands is not always guaranteed.

But at this point, a detail should be highlighted. That they are renewable energies does not mean that they are not polluting . It is therefore that renewable energy sources are classified as polluting and non-polluting or clean.

Among the non-polluting or clean sources we find the following:

• The wind, which generates wind power.
• The heat coming from inside the earth is geothermal energy.
• Rivers and freshwater streams generate hydraulic or hydroelectric energy.
• The Sun produces solar energy .
• The seas and oceans generate tidal energy.
• The waves give wave energy.
• The union of bodies of fresh water and bodies of salt water is blue energy.

On the other hand, polluting renewable energies are those that come from biomass or organic matter. These can be used directly as fuel by burning or can be used once converted into bioethanol or biodiesel. As they are polluting energies, the problem that these types of energies have is the same as the problem that polluting energies have: the emission of carbon dioxide by combustion.

In addition, we recommend reading this other AgroCorrn article on Are renewable energies viable alternatives?

Now that we know what renewable energies are and what types there are , we are going to delve into some examples of these forms of energies, which, as we have seen, vary depending on the source that generates them.

• Wind energy: that obtained from the force of the wind or air currents. Wind turbines transform the energy from the movement of these currents into electrical energy.
• Geothermal energy : the energy source is found inside the Earth, as thermal phenomena that occur under the earth’s crust are used.
• Solar energy: the best known, that which is obtained from solar radiation and which is collected through solar panels.
• Hydroelectric or hydraulic energy : it comes from the energy created by the “waterfalls” that occur in rivers, which make certain turbines work that produce the movement of an electric generator that generates energy.
• Blue energy : also called osmotic power, this energy is obtained due to the difference between the salt concentrations of river water and sea water. It is especially useful in regions where the rivers are very large, as greater amounts of energy will be produced. The only waste generated is brackish water.
• Tidal energy : this type of energy takes advantage of the energy produced by waves (wave energy), tides, salinity gradients (osmotic energy) or differences in ocean temperature.
• Biomass: this type of energy takes advantage of the organic matter that is formed due to biological processes of living beings such as plants or animals, as well as their remains and waste. These generated products can be burned (combustion) and obtain energy or transform them into other substances such as fuel or food that can be used later.
• Biofuels: these would be derived from the aforementioned form of energy. They are mixtures of substances of organic origin that are used as fuels. These biofuels can be obtained from different types of plants such as corn, soybeans, sunflowers, palm trees and even eucalyptus and pine trees.

Non-renewable energies, as we discussed earlier, refer to conventional forms of energy , those whose resources from which they are obtained are limited, that is, they do not regenerate themselves like renewable energies.

The most common thing is that to generate these energy sources, fossil fuels are burned , which in their combustion cause the emission of a large amount of greenhouse gases . These gases today are one of the main responsible for climate change, as their amount in the atmosphere is increasing very rapidly.

Within this type of non-renewable energy we can find two main groups:

Fossil fuels

Fossil fuels , such as oil (liquid form), coal (solid), and natural gas (gas). These fossil fuels come from the biomass generated millions of years ago that have been converted into these fuels after undergoing adequate pressure and temperature conditions.

• Petroleum: petroleum is an organic compound that is composed of a mixture of hydrocarbons that are insoluble in water and that was formed from the transformation of organic matter that accumulated in the form of sediments.
• Coal: Coal is a sedimentary rock, again of organic origin, formed from plant remains that decompose and accumulate in swampy areas.
• Natural gas: in this case, it is a hydrocarbon resulting from the mixture of gases of natural origin, mainly methane, and that is formed by the decomposition of several layers of plants and matter of animal origin exposed to intense heat and pressure during millions of years.

The nuclear energy

The other group of non-renewable energies is that corresponding to nuclear energy . Matter is made up of atoms, which are made up of a nucleus and one or more electrons distributed in shells (electron cloud) on the nucleus, which in turn is made up of one or more protons and an equal number of neutrons.

But what does all this have to do with nuclear power? The atomic nucleus of some elements such as uranium, can be disintegrated and release energy, which is used by thermonuclear power plants to produce electricity, that is, nuclear energy is obtained by breaking atoms of some radioactive minerals (fission). However, the nuclear waste that is produced takes time to lose its radioactive properties, and it can take time for many to disappear.

To conclude this article, below, we are going to summarize all the information presented in the previous sections.

As we said, renewable energies are those that come from almost unlimited natural sources, but that need a period of renewal to be able to recover. There are non-polluting or clean renewable energies and polluting renewable energies.

Among the clean renewable energies we highlighted wind energy, solar energy, hydroelectric energy, geothermal energy, tidal energy, wave energy or blue energy. As polluting renewable energies, we highlighted those whose source is biomass or organic matter. Its problem is that, as in conventional energies, its combustion produces carbon dioxide emissions into the atmosphere.

On the other hand, we said about non-renewable energies that, unlike renewable energies, they are obtained from resources that are limited and do not have the capacity to regenerate themselves. The most common is that these energies are obtained, above all, from the burning of fossil fuels such as oil, coal or natural gas. The combustion of these materials contributes to current climate change by emitting a large amount of greenhouse gases.

There is another group of non-renewable energies, that of nuclear energy. Nuclear energy comes from the fission process, the process by which the atomic nucleus of atoms disintegrates to later release energy, used by thermonuclear power plants for the production of electricity. The great disadvantage of nuclear energy is that nuclear waste takes a long time to disappear and lose its radioactivity.

If you want to read more articles similar to Renewable and non-renewable energies: examples and summary , we recommend that you enter our Renewable Energies category .