Current socioeconomic models are based on their dependency in relation to fossil fuels. The energy base of our society is based on the use of so-called conventional energies: coal, oil, natural gas and hydroelectricity.
Conventional energy sources have caused major negative impacts on the environment. Energy models based on the use of fossil fuels and their burning process to obtain energy launch the atmosphere pollutant gases that aggravate the greenhouse effect, increase global warming and alter the climatic conditions of several regions. These models are also problematic because they are non-renewable resources, and their depletion is already part of intense debates about the need to expand the energy matrix through the use of alternative energy sources.
Renewable and non-renewable energy sources
Renewable energy sources are those available in nature for a long period, which are capable of renewing themselves in a short period of time, such as solar energy and wind energy. Thus, it can be said that they are inexhaustible resources. On the other hand, non-renewable sources are those that run out over time, not being able to renew themselves, like fossil fuels.
To learn more, click here: Non-renewable energy sources
Mind Map: Alternative Energy Sources
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Advantages and disadvantages
Alternative energy sources are an option to replace the current energy model, which is based on the use of fossil fuels (polluting and exhaustible).
See the main ones benefits of the use of alternative energy sources:
→ They are considered clean (less polluting) and inexhaustible energy, which can be regenerated in a short time in nature.
→ The negative impacts on nature are much smaller compared to the use of non-renewable sources.
→ Compared to the use of nuclear energy, alternative sources pose much lower risks.
→ The use of these sources is a way to reduce dependence on the current energy model (use of fossil fuels).
Some alternative energy sources can impact the environment. See the main ones disadvantages of the use of alternative energy sources:
→ Alternative energy sources, such as solar and wind, produce energy at relatively low prices, but their structural construction costs are still very high. However, with technological advances, these costs tend to be increasingly lower, making access to these energy sources feasible for the majority of the population.
→ Despite being considered clean, wind energy, which depends on the installation of wind turbines, is capable of causing changes in the landscapes of the places where it is installed and can also interfere with the migratory flow of birds from these regions.
→ The use of biofuels can intensify problems related to deforestation. The use of biomass to obtain energy through the burning of plants, wood and materials plants and animals, requires expansion of areas for agriculture or deforestation to obtain wood.
Alternative types of energy
Alternative energy sources have greater availability and cause less environmental impacts, however they are little used because they need greater technological investments that make their use economically viable.
The use of solar energy represents a clean and cost-effective option.
Among the alternative energy sources, the following stand out:
1. Solar energy
The use of solar energy as an alternative energy source has numerous advantages. It's an energy matrix, is clean, renewable, abundant and that presents good cost-benefit. In the United States, it is already widely used in water heating and electricity generation. Countries located in the tropics – such as Mexico, Bahamas, China, Brazil and Paraguay – have great potential for obtaining this energy, due to the great amount of sunlight they receive. The use of sunlight, however, still requires advances in technology for its use to be economically viable.
Electric energy through sunlight can be obtained in two ways:
• direct: through photovoltaic cell panels or through collectors installed on the roof of homes.
• indirect: through power plants, built in areas where insolation is abundant, where numerous solar collectors are installed.
Wind turbines used for wind power generation.
2. wind energy
O wind it's a natural resource abundant and, when intense, it can be used to obtain energy, produced at a generally low cost. Its use as a power generator began in the 19th century. According to Exame Magazine1, in 2017, about 18% of the energy generated in the United States comes from alternative energy sources, such as wind energy. Brazil still does not stand out in the use of wind energy, but it has shown some advances, especially in the states of the Northeast and South regions, which have the presence of trade winds.
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The obtainment of wind energy occurs through equipment called wind turbines, that convert to kinetic energy of winds into electrical energy. Because this process does not emit polluting gases into the atmosphere, this energy is considered a clean font. Despite this, the installation of wind turbines on farms causes changes in the landscape and harms the birds in their migratory routes. Wind turbines still need advances in their development, as they still have a high cost.
Know more: Wind energy in the state of Ceará
Biofuels are produced by burning biomass products such as plants and wood.
3. Biofuels
The use of biofuels is done through the use ofbiomass. Energy from biomass can be obtained through burning of plants, wood, plant materials and animalss. There are several processes that generate electricity through biomass, such as direct combustion, fermentation, gasification, among others. It's an energy source little pollutant, and its resources are renewable. Biofuels produced by using biomass are:
→ Ethanol: generated from sugarcane, eucalyptus, corn or sugar beet. It is a renewable fuel and less polluting than gasoline.
→ Biodiesel: produced from vegetable fats or oil plants. It was recognized as an ecological fuel, as it emits about 60% less carbon dioxide and 90% less sulfur than traditional fuels.
→ Biogas: obtained through anaerobic reactions (without oxygen) of organic matter found in waste produced in urban areas and deposited in landfills. It is used as a household gas and as a vehicle fuel.
The use of biofuels, however, has aspects negatives. Some of these alternative energy sources, to be produced, use a lot of water. Agriculture is already responsible for around 70% of the world's water consumption. The expansion of this economic activity, in addition to increasing the use of water to enable the production of alternative energies, would demand an increase in the occupation of land and, consequently, the logging.
Wave power is used to produce electricity.
4. ocean energy
The energy of the oceans is obtained through the force generated by the displacement of water masses, which generates energy accumulation. The use of this type of energy matrix can be done through wave energy, tidal energy, energy from ocean currents or thermal energy from the oceans. The use of these energies requires advances and improvements so that this alternative source can be disseminated throughout the world. The energy of the oceans is considered a clean energy source, for minimally harming the environment. Norway, for example, is one of the countries that already uses wave power to produce electricity.
Geothermal power plant in Iceland.
5.Geothermal energy
Geothermal energy comes from the heat generated inside the planet. This heat is transformed into electrical energy in geothermal plants, which are generally built in areas that have volcanic activities, since, in these places, steam and hot water are found at shallower depths and outcrop in the surface. The heat is used to produce steam, which drives the power plants' turbines. Finally, generators transform kinetic energy into electrical energy. The use of this energy source is only possible because of the Earth's ability to retain heat within it.
Geothermal energy has aspects positive, as low maintenance costs and non-aggression to the ground. However, the aspects negatives they are unavoidable, as the production of this type of energy generates the emission of sulfur dioxide, a gas that is highly harmful to health. There are also occurrences of land sinking and lake contamination in places where geothermal plants are installed.
The expansion of energy resources is a world need, since the depletion of non-renewable energy resources it is already a reality of our society. In addition, the current energy model has aggravated weather problems, as a result of the intense emissions of polluting gases into the atmosphere, through the burning of fossil fuels. For this to be possible, society must choose alternatives that reduce environmental impacts. In addition, public and private investments in technologies that generate clean energy are needed, as the population needs to have access to these alternative sources.
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1https://exame.abril.com.br/economia/energia-solar-e-eolica-poderiam-abastecer-ate-80-dos-eua/
By Rafaela Sousa
Graduated in Geography
