Alternative energies

What are alternative energies?

The alternative energies They are all those energy sources that are renewable and clean, that is, they do not pollute or they do so in a low proportion. They are an alternative to energy sources from fossil fuels such as oil, coal, gas or radioactive elements.

These energies come from inexhaustible sources or that will persist as long as the planet continues to function. The main alternative energies are hydroelectric (based on the force of water), solar energy and wind energy (provided by the force of the wind).

Others are geothermal energy (coming from the internal heat of the Earth) and tidal energy (based on the coming and going of the tides in the sea). In the same way, the wave energy or energy provided by the waves of the sea.

Alternative fuels have also been developed, such as biofuels from burning plant matter or processing it to produce liquid fuel. Like the production of gas from the decomposition of organic matter, the so-called biogas.

These alternative energies have undoubted advantages, although they also carry some disadvantages. Among the first are its condition of being renewable and little polluting, while among the disadvantages are its lower energy efficiency and storage problems.

Types of alternative energies

Alternative energies are all those that offer different options to traditional non-renewable energy sources and that have been highly polluting. There are different types of alternative energy, depending on the source that supplies said energy.

Hydroelectric power

It is a motive energy (energy that generates movement), from which work can be produced. In this case, the movement is produced by the water currents of the rivers, which when passing through turbines can generate electricity.

Electricity is stored in accumulators and distributed through the electrical network. To achieve this, large dams are built on mighty rivers, such as the Three Gorges Dam on the Yangtze River in China (the largest in the world)..

The dam produces a difference in height so that the water falls like a waterfall and passes through the turbines. Turbines rotate and activate an alternator, which is a machine that transforms movement into electricity.

Solar energy

Solar energy is the main source of energy on the planet and all other energies are considered to come from it. But in this case, reference is made to the direct use of solar energy through the use of solar panels.

Solar panels are plates that have photovoltaic cells that capture the sun's radiation and transform it into electricity. The photovoltaic or photoelectric cell is a device that when sunlight hits it, generates a movement of electrons.

As these electrons move, an electrical current is produced that is stored in a battery or accumulator. For example, in Abu Dhabi (United Arab Emirates), a solar power plant is being built that will have 4 million solar panels and will produce energy for 160,000 homes..

Wind power

The energy is produced by the movement of the air, that is, the winds, which move large blades or blades of a wind turbine. The latter is a device placed high on a pedestal or column, which has blades like a fan and an alternator..

Therefore, when the wind turns the blades, they move the alternator and produce an electrical current that accumulates in batteries. Wind power has been used for many centuries, such as in the windmills used to grind wheat.

For example, the famous windmills that Don Quixote pounced on with his spear. Today wind farms such as the offshore wind farm Walney Extension, the largest in the world, provides electricity for 590,000 homes.

Geothermal energy

The interior of planet Earth is made of molten material at a very high temperature, which makes the water in underground reservoirs boil. The water vapor that is produced, rises and heats the rocks in its path.

This heat from water and rocks can be harnessed as energy for various uses. Both to produce electricity, to achieve that the pressure of water vapor move turbines, and to heat rooms or water.

In Iceland, for example, the Nesjavellir geothermal plant provides hot water to the capital city, Reykjavik..

Seawater energy

Tidal energy is that produced by the force of sea water displaced by the rise and fall of the tides. The mass of seawater is periodically affected by the force of gravity of the Moon and the Sun, causing it to rise and fall and move closer to or farther from the coasts..

To take advantage of this movement, a device is placed that allows sea water to move the blades of a turbine. This in turn turns the coil of an alternator and produces electricity.

An example of this is the tidal power plant in the estuary of the Rance River (France), which produces electricity for 225,000 people.

Wave energy

This energy follows the same principle as hydroelectric energy and tidal or tidal energy. In this case, the force that moves the turbine blades and activates the alternator to produce electricity is the force of the waves of the sea..

To make it work, a series of devices are placed in the sea that receive the impulse of the waves. This is an indirect form of energy from the wind, since it is the wind that produces the waves..

This type of energy is one of the least developed, still in the research phase. However, there is at least one commercial plant in operation, the Mutriku Breakwater Plant in the Bay of Biscay, Spain.

Biofuel-based energy

Another way to produce alternative energy is through the production of biofuels, that is, fuels based on plant matter or biomass. This consists of taking advantage of the possibility of producing alcohol by subjecting large quantities of plant products to fermentation..

For example, from sugar cane, just as rum is produced, alcohol (bioethanol) can be produced for use as fuel. Almost any crop rich in carbohydrates or oils serves this purpose, for example corn, cassava, soybeans and many palms, among others..

Biogas-based energy

Just as natural gas obtained from the interior of the Earth is used, which is a non-renewable resource, gas can be produced from organic matter. This is achieved using biodigesters, which are tanks in which organic matter is deposited to undergo a decomposition process..

This decomposition is generated by bacteria and other microorganisms in an environment without oxygen (anaerobic), producing gas in the process. The gas produced includes mostly methane (useful as fuel), in addition to CO_two and other gases to a lesser extent.

Hydrogen energy

It is another source of alternative energy, whose raw material is abundant in the universe, since hydrogen can be obtained from water or plant matter. In addition, its use does not generate polluting waste, although for now its greatest limitation is technological, due to the cost of its production from water..

However, there are already hydrogen-based fuel cells that allow moving vehicles, having as the only waste water. On the other hand, they have been used in spacecraft such as the Apollo series to produce electricity and water..

Advantage

• Alternative energies are renewable, that is, they can be produced over and over again, without the danger of depleting their reserves.
• These energies do not pollute or do so to a lesser extent than fossil fuels or nuclear energy. Therefore, they do not have a significant impact on the greenhouse effect that causes global warming..
• They have a lower impact on health, precisely because they produce little waste and cause less environmental impact.
• Its development allows the generation of new jobs, both in the phases of generating the technology, and in its installation, operation and maintenance.
• Facilities where alternative energies are produced are safer and less expensive to maintain.

Disadvantages

• They are less energy efficient in terms of the amount of energy produced per investment made. In most cases it is required to dedicate large areas of land or sea to produce profitable energy.
• The possibility of producing these types of energy is unequal in the world, since they depend on the climate and geographical conditions. Although fossil fuels are not found in all parts of the world, their energy is easier to transport.
• A disadvantage is the technological limitations, that is, not having efficient technologies in some cases. But in any case, it is hoped that this is a temporary disadvantage, to the extent that investment is made in the generation of new technologies.
• In most cases, the initial investment required to install a production plant is high. Although depending on the type of energy, this is offset by lower maintenance costs and, above all, a reduction in environmental impact..
• An important limitation is the storage of the energy produced, which in general is electrical energy. This is due to the fact that until now its storage in batteries or accumulators does not reach the required capacity and efficiency..
• In cases such as biofuels, by using agricultural land to produce their raw material, they compete with food production.
• In most cases, alternative energy generating plants produce a considerable visual impact.
• Although they have a much lower ecological impact than non-renewable energy, alternative energy can also cause it. For example, wind turbines have been found to kill many bats and insects by impacting blades..

References

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