We hear more and more about clean energies or green energies. These are energies that are characterized by their respect for the environment and their low impact on the surroundings, completely contrary to dirty or polluting energies. However, would you be able to say what they are and what differentiates them from other energies?
If you want to learn a little more about what clean or green energies are , as well as learn about some of the most important ones, keep reading EcologíaVerde and we will tell you in detail and with examples.
What are clean or green energies?
Clean or green energies , as their name suggests, are those that do not produce polluting or harmful waste for the planet and for health. They are energies that are obtained from different natural sources , such as the sun, wind or rain. In all cases of clean energies, we are also talking about renewable energies , since they are energies that, potentially, will never run out.
These types of energy are currently being promoted the most in order to slow down and even counteract the effects of climate change . This process is known as the energy transition, which consists of moving from an energy sector based on carbon (energy obtained from the burning of fossil fuels such as coal and oil) to one based on renewable energy, where clean energy plays a leading role.
In this other article from Green Ecology we explain the importance of clean energy for the environment .
What are clean energies or green energies?
Although clean energy can take many forms and is a sector that is constantly changing and progressing, the most widespread clean or green energies currently are the following:
Solar energy
This is the energy obtained from the light and heat of the sun. It can be used in two ways, depending on whether the light or the heat is used. In the case of using sunlight, this is done through solar panels, which, broadly speaking, are devices capable of transforming the photons of light into electric current that can be used for human activities. This type of energy is called photovoltaic.
In the case of harnessing the heat of the sun, we are talking about solar thermal energy. This type of solar energy is harnessed through large installations with many mirrors that direct and concentrate the sun’s rays on a single point, thereby heating this point considerably and, in this way, activating a mechanical system that is capable of producing movement that will later be transformed into electrical energy useful for humans.
Hydropower
This is the energy obtained by harnessing the flow of rivers and the natural movement of water. In the case of hydraulic energy , the energy is obtained by installing turbines on the banks or dams of rivers, which allows the turbines to move like water mills. This movement is then converted into electrical energy that, again, can be used for human activities.
Wind energy
Wind energy is energy obtained from the wind. The system is similar to that of hydroelectric power, but in this case, windmills (also called aerogenerators) are installed in places where the wind is abundant, such as esplanades on land or in coastal areas on the sea. The wind makes the blades of the windmill turn and, in this way, the movement can be converted back into electricity that is sent to the electrical grid.
Tidal energy
This is the energy obtained by harnessing the tides. This is achieved by installing an alternator that, taking advantage of the rise and fall of the tides, transforms the movement of the sea into electricity.
Geothermal energy
In the case of geothermal energy, we are dealing with an energy that is obtained by harnessing the heat from the Earth’s interior. Using an installation that captures the heat, a mechanical system is activated which, in turn, is responsible for producing electrical energy that can be used for human activity.
Are nuclear energy and biofuels green or clean energies?
Nuclear energy is a very particular energy, since it is not associated with carbon and, therefore, it might initially seem that it would be a clean energy. However, nuclear energy is not exempt from producing highly polluting waste. In this case, radioactive waste that has to be properly isolated to avoid very serious damage to the environment and the health of living beings. Therefore, although it is an energy that is not linked to the burning of fossil fuels, it cannot be considered as a clean energy.
On the other hand, we find biofuels . This type of energy is obtained from the burning of fuels that are obtained from the reuse of organic matter. This can be done by burning wood such as pellets, or by burning biogas, a type of gas obtained from the putrefaction of organic matter in certain circumstances. This type of energy promises to have a relevant role in the future, since they are much more environmentally friendly fuels. In fact, because it is an energy that can be obtained from organic matter, at least in principle, it could be considered a fully-fledged renewable energy. However, it is important to bear in mind that, when it is burned, greenhouse gases (GHG) are released, although in much smaller quantities than when coal or petroleum derivatives are burned. Therefore, despite being considered by many as a renewable energy, one cannot technically speak of a clean energy as such.
