Renewable energies: sources and types

Renewable energies are those that are obtained from natural resources that are continually renewed and are not depleted. These energy sources are cleaner and more sustainable than fossil fuels, which are responsible for much of climate change and environmental pollution. In addition, renewable energies are cheaper and generate more jobs than fossil fuels.

There are different types of renewable energies, depending on the natural source that is used to produce electricity, heat or fuel. Some of the most common types are:

• Solar energy: It is what uses solar radiation to generate electricity or heat. It can be captured through photovoltaic panels, which convert light into electrical current, or through solar thermal collectors, which heat a fluid. Solar energy can also be concentrated using mirrors to produce steam and drive turbines. Solar energy is one of the most abundant and accessible, since the sun is an inexhaustible source of energy.
• The eolic energy: It is the one that takes advantage of the force of the wind to move propellers connected to an electric generator. The propellers are grouped into wind turbines, which can be installed on land or at sea. Wind energy depends on the speed and direction of the wind, so it is usually combined with other energy sources to guarantee supply.
• Hydroelectric power: It is what uses the movement of water to generate electricity. You can take advantage of the fall of water from a dam, the flow of a river or the waves and tides of the sea. Hydroelectric energy is one of the oldest and most widespread, but it also has some negative environmental impacts, such as the alteration of aquatic ecosystems or the displacement of populations.
• Biomass and biofuels: They are those obtained from organic matter of plant or animal origin. Biomass can be burned directly to produce heat or electricity, or transformed into biogas or bioliquids through chemical or biological processes. Biofuels are liquid fuels derived from biomass, such as bioethanol or biodiesel, that can be used in internal combustion engines. Biomass and biofuels are renewable energy sources as long as the natural cycle of growth and regeneration of organic matter is respected.
• geothermal energy: It is what uses the internal heat of the Earth to produce electricity or heating. It can be extracted by drilling in areas where there is a high underground temperature, such as volcanoes or hot springs. Geothermal energy is a constant and clean source of energy, but requires a high initial investment and may have associated geological risks.

Solar energy: how is it obtained and what are the benefits?

Solar energy is a renewable energy source that is obtained from the electromagnetic radiation emitted by the Sun. There are two main ways to harness this energy: photovoltaic solar energy and solar thermal energy.

Photovoltaic Solar Energy

Photovoltaic solar energy consists of transforming sunlight into electricity using cells called photovoltaics, which are made of semiconductor materials such as silicon. These cells are grouped into panels or modules that are installed on the roofs of homes, in fields or in solar plants.

The advantage of photovoltaic solar energy is that it does not produce polluting emissions or waste, and that it can generate electricity in remote or isolated places where there is no access to the electrical grid. Additionally, the cost of solar panels has decreased significantly in recent years, making this technology increasingly competitive and cost-effective.

Thermal solar energy

Solar thermal energy consists of harnessing the Sun's heat to heat a fluid, such as water or air, which is used for domestic or industrial purposes. To do this, devices called solar collectors are used, which can be flat or parabolic troughs, depending on their shape and their degree of concentration of solar radiation.

The advantage of solar thermal energy is that it reduces fossil fuel consumption and greenhouse gas emissions, and can provide low-cost heat and hot water. Additionally, this energy can be stored in reservoirs or tanks for later use when there is no Sun.

Benefits of solar energy

Solar energy has multiple benefits for the environment and society. Some of them are:

• It is clean and renewable energy, which does not contribute to climate change or atmospheric pollution.
• It is abundant and free energy, which does not depend on scarce resources or geopolitical factors.
• It is a decentralized and democratic energy, which favors local development and citizen participation.
• It is a versatile and adaptable energy, which can be used for different applications and scales.
• It is an energy that generates employment and wealth, which drives innovation and economic growth.

As you can see, solar energy is a sustainable and efficient option to meet current and future energy needs. Therefore, it is important to promote its use and dissemination among the population and institutions.

What is eolic energy?

Wind energy is energy obtained from the wind, that is, from the kinetic force generated by air currents. It is a renewable, clean and abundant source of energy, which does not produce polluting emissions or dangerous waste.

How is wind energy obtained?

Wind energy is obtained through wind turbines, which are large windmills that transform the force of the wind into electricity. Wind turbines are made up of a rotor with blades that rotate when driven by the wind, an electrical generator that converts the rotary movement into electricity, and a tower that supports the assembly.

What are the benefits of wind energy?

Wind energy has multiple benefits for the environment and society. Some of them are:

• It is an inexhaustible source of energy available in almost the entire planet.
• It is a clean energy source that does not contribute to climate change or air pollution.
• It is a cheap and competitive source of energy that reduces dependence on fossil fuels and promotes energy diversification.
• It is a source of energy that generates employment and local development, especially in rural and isolated areas.
• It is an energy source that respects the landscape and cultural heritage, as long as adequate planning and management is carried out.

What is hydroelectric power?

Hydroelectric energy is energy obtained by transforming the force of water into electrical energy. To take advantage of this force, large hydraulic infrastructures are built, such as dams and power plants, which extract the maximum potential of this renewable, emission-free and indigenous resource.

How is hydroelectric energy obtained?

Hydroelectric energy is obtained by circulating a flow of water through a circuit that bridges the difference in level between two points located at different heights. Water gains speed as it loses potential energy and gains kinetic energy. This kinetic energy is transformed into mechanical energy as it passes through a turbine, which spins a generator to produce electricity. The water leaves the turbine and returns to the river with the potential energy corresponding to the drainage point.

What are the benefits of hydroelectric energy?

Hydroelectric energy has several benefits, including:

• It is a renewable energy source, since it uses the natural water cycle and does not consume or deplete the resource.
• It is a clean energy source, since it does not produce greenhouse gas emissions or other atmospheric pollutants.
• It is a source of indigenous energy, since it takes advantage of the water resources available in the territory and reduces dependence on imported fossil fuels.
• It is a flexible energy source, since it can adapt to variations in electrical demand and contribute to the stability of the system.
• It is an economical energy source, as it has low operation and maintenance costs and a long useful life.
• It is a source of energy that generates social and environmental benefits, such as rural development, job creation, promotion of tourism, flow regulation, flood prevention and improvement of water quality.

What is biomass and biofuels?

Biomass is organic matter of plant or animal origin that can be used as an energy source. Biofuels are liquid or gaseous fuels obtained from biomass.

How are biomass and biofuels obtained?

Biomass can be obtained in various ways, such as the cultivation of energy plants, the use of agricultural and forestry waste, the treatment of urban waste and animal husbandry. Biofuels can be produced through physical, chemical or biological processes that transform biomass into fuels such as ethanol, biodiesel or biogas.

What benefits do biomass and biofuels have?

Biomass and biofuels have several environmental, economic and social benefits, such as:

• They reduce greenhouse gas emissions by replacing fossil fuels.
• They take advantage of renewable and local resources, which reduces energy dependence on the outside and generates employment and rural development.
• They contribute to the sustainable management of natural resources and waste, preventing their burning or uncontrolled dumping.
• They improve air quality by emitting fewer pollutants than fossil fuels.

What is geothermal energy?

Geothermal energy is energy obtained by taking advantage of the heat inside the Earth. This heat is transmitted through fluids that circulate through the deepest layers of the planet, such as water or steam. These fluids can come to the surface naturally, forming geysers or hot springs, or be extracted by drilling.

How is geothermal energy obtained?

To obtain geothermal energy, facilities called geothermal power plants are used, which capture heat from underground fluids and transform it into electricity or useful heat. There are different types of geothermal plants depending on the temperature and state of the fluids:

• Dry steam plants: they use the steam that comes directly from the wells to drive a turbine and generate electricity.
• Wet steam plants: they separate steam from the water coming out of the wells and use it to drive a turbine and generate electricity. The water is injected back into the subsoil.
• Binary cycle power plants: use a fluid with a lower boiling point than water to drive a turbine and generate electricity. The fluid is heated by water or steam coming out of the wells and then condensed and recycled. The water or steam is injected back into the subsoil.
• Direct heat plants: they use the hot water that comes out of wells to heat buildings, greenhouses, swimming pools or industries.

What are the benefits of geothermal energy?

Geothermal energy has several environmental and economic benefits:

• It is a renewable energy source, since the Earth's heat is constantly regenerated.
• It is a clean energy source, since it does not produce polluting emissions or dangerous waste.
• It is an efficient energy source as it has high performance and low operating cost.
• It is a safe source of energy, since it does not depend on external factors such as the weather or the market.
• It is a diverse energy source, as it can be used to generate electricity or heat for different uses.