What are renewable energies?
Renewable energy is understood as any source of energy obtained through virtually inexhaustible natural sources, either because of the immense amount of energy they contain (sun, geothermal energy, etc …) or because they are capable of regenerating by natural means ( biomass, hydraulic, etc.).
Renewable energies are clean resources available in abundant amounts in nature itself. In addition, by taking advantage of the resources in an autochthonous way, the energy independence of the countries or communities that develop them is favored, thus reducing the need for fuels or energy sources from other countries or regions. Taking advantage of the renewable energy sources available in your area, provides an invaluable energy resource, since it is an unlimited, local, free, environmentally friendly and future good.
What types of renewable energy exist?
There are various types of renewable energy sources. Below we will detail the main examples of renewable energy sources currently used:
- Photovoltaic solar energy: It consists of directly transforming solar radiation into electricity through photovoltaic panels. The solar radiation that falls on said panels excites the electrons of the semiconductor material from which they are manufactured, to generate a potential difference that generates electric current. Photovoltaic solar energy is widely used today and is booming. The great cost reduction in its materials suffered during the last decade, together with its scalability (we can generate energy with just one panel), make it the ideal solution to produce renewable energy both on a large and small scale.
- Thermal solar energy:It consists of harnessing the thermal energy from the Sun to transfer it to a medium that carries heat, usually water or air. There are two main uses for this type of energy. Use in small facilities (homes, etc …), where technology is used for heating domestic hot water, or its use in large solar thermal power plants. In these plants, the heat received is concentrated at a single point to generate steam under pressure, which interacts with a turbine to generate electricity, with a similar operation to that of a thermal or nuclear power plant. The big difference is that in fossil power plants some fossil fuel is used to generate steam and in nuclear plants the fuel is uranium, while in solar thermal power plants the fuel is the Sun.
- Wind energy: It consists of harnessing the kinetic energy produced by the wind. Wind turbines or windmills are responsible for taking advantage of air currents to generate electricity through the movement of their blades. We can find large-scale wind energy solutions, such as wind farms or offshore wind farms, where a large number of production mills are concentrated. Or small-scale solutions, with mini-wind generators, ideal to complement isolated grid installations, which already have another source of electricity generation (for example photovoltaic).
- Biomass: The biomass energy comes from the waste of organic vegetable and animal matter. It includes waste from agricultural, forestry, livestock, wood industry, etc. Biomass has various uses, the most common being, generation of biofuels for transport, hot water and heating, as well as the production of electricity .
- Hydraulics: Hydraulic energy consists in harnessing the kinetic energy of a large amount of water. Kinetic energy is conferred to the water by a change in height (usually a dam) by causing the water to spin a turbine, the movement from which it generates electricity. This type of generation is conditioned by the amount of water available and limited by weather conditions, such as periods of drought.
- Geothermal: It is the source of energy coming from beneath the earth’s surface. In some areas, the earth stores energy in the form of heat, such energy can be used for direct heat production or power generation.
Advantages of renewable energy
- Renewable energies do not produce emissions of CO2 and other polluting gases into the atmosphere, so the greenhouse effect is reduced. With cleaner air, both the human population and the planet earth in general will gain in health.
- They do not generate waste that is renewable energies are very easy to dismantle and do not require guarding their waste for millions of years, as happens for example with nuclear energy.
- They are inexhaustible , since they come from sources such as the sun, wind, water or rain. Other traditional sources of energy, such as coal, oil and gas, are limited and every day that passes, world reserves run out hopelessly.
- Avoid external dependence. Renewable energies have allows countries to develop its own technologies , so example it is a world leader in the manufacture of solar panels and windmills. In addition to a stable and established production based on renewable energies, the energy price (the water bill, electricity or heating) would not suffer so many ups and downs.
- Renewable energies create five times more jobs than conventional ones: manufacturing, installation, maintenance and commercialization. Thus contributing to the improvement in the economy of the country.
- Local economic prosperity – Renewable energies make the area in which they are installed more autonomous , since it helps the development of the area in which they are installed, both industrially and economically
- Safety – Renewables are safe energies that do not pollute, nor do they pose a health risk. In addition, their waste does not pose a threat to anyone.
- Favorable public opinion – It is not a minor thing, to have the citizenship discourse in favor. Public opinion can be a determining element and, in the case of renewable energies, there are more voices in favor than against, which makes it easier for them to reach the world, little by little. The perception of the people is favorable and the general consideration is that renewable energies are beneficial for everyone.
Disadvantages of renewable energy
- The same energy is not always obtained with them, most renewable energy sources suffer from ups and downs depending on the weather .If the right conditions are not met, no energy is produced. So we can say they are intermittent (solar, wind). They only produce under certain conditions and need other sources of support to ensure continuous production.
- The projects and the construction of new renewable energy plants carry a great economic cost , so it is necessary to make a large investment.
- Availability – The availability of renewable energy can be a problem today. They are not always available and you should expect enough storage. This has a close relationship with the fact that they are becoming increasingly popular.
- Necessary space – One of the great disadvantages of renewable energy is the space needed to start developing them. Depending on the source they require, they need a large space to be able to develop , or they have a large system for some effect to arise (this is the case for example of solar panels, of which we will need a considerable amount if we want to generate a high electrical energy).
- Diffuse nature – On the other hand it should be added that a clear problem inherent in renewable energies will be that many of them have a diffuse nature , with the exception of geothermal energy which, however, is only accessible where the earth’s crust is Fine, like hot springs and geysers.
- They are not available in all locations. Each zone has better natural resources from one source or another for obtaining energy. A photovoltaic installation does not produce the same in southern Australia in northern Germany.
- Some renewable energy sources need large constructions that affect the ecosystem where these facilities are executed (dams, geothermal plants, wind farms …). However, its environmental impact is always less than that produced by conventional power generation plants.
Advantages and disadvantages of each renewable energy
ADVANTAGES OF SOLAR ENERGY
We begin the review of the advantages of solar energy .
- Renewable energy – It is obvious but one of the main advantages of solar energy is that it is renewable energy . That is, it has all the advantages previously exposed in all renewable energies.
- Clean energy – Solar energy is also a totally clean energy . No chemical elements are required to convert it into heat or electricity and it does not emit polluting substances into the atmosphere.
- Profitable investment – Solar energy is much cheaper in the medium and long term and allows progress in the direction of self-sufficiency. In addition, it serves both to produce heat or electricity in homes and in public places, for example for lighting (there are solar lamps that accumulate energy during the day to produce light at night).
- Silent – One of the great advantages of solar energy is that it emits no noise or noise pollution . It seems somewhat smaller but other energies require giant-sized machinery whose noise becomes unbearable.
- Minimum maintenance – Another element to take into account in solar energy is the minimum maintenance required by its facilities, especially when compared with other renewable energy.
- Investment in isolated areas – Until solar energy arrived, few people had thought about investing in isolated , even desert areas where, however, there are more hours of sunlight than in most sites. That is, more sunlight, more energy. In addition, in these areas it is difficult to carry a power grid because of the bestial investment it requires. In this way, solar energy can be key to its development.
DISADVANTAGES OF SOLAR ENERGY
As with everything, there is always a negative side. In this case, the disadvantages of solar energy are minor compared to the advantages, but we must know them and keep them in mind.
- Large installation – If we want to have an important production of energy and be able to commercialize with it or use it for our own consumption, a large installation of solar panels is necessary. Obviously, this requires ample space to install.
- Area with sunlight – Solar panels perform more depending on the area where they are placed, and are especially suitable for areas where there is a high incidence of sunlight . Obviously, this rules out some areas where it rains 300 days a year or where the weather is rather cloudy during most of the year.
- Initial investment – Although solar energy is one of the most profitable energies in the short term, the truth is that starting with it requires a significant initial investment . As we have said, only in the field, boards and installation, will an important amount of money be left.
- Taxes and legislation – In some countries such as Spain, the installation is very precarious and complicated, due to legal obstacles and high taxes that prevent its development. The famous Sun Tax has slowed the development of solar energy in Spain, which, little by little, is recovering the speed of years ago, although already located in the tail car of investments in Europe.
- Storage limitation – The fact that obtaining solar energy is limited to sunny hours greatly limits energy storage . Well, it is not always convenient to store electricity when the sun is hitting. When it is convenient to do it at night, it becomes a problem, leaving the efficiency of this energy in a very low range
ADVANTAGES AND DISADVANTAGES OF WIND ENERGY
And from the sun we pass to the wind. Another renewable energy with more pull , wind, also has its good things and its bad things. Therefore, we will review the advantages and disadvantages of wind energy .
ADVANTAGES OF WIND ENERGY
We start with the advantages of wind energy . A way to extract energy that, for decades, has changed the landscape of the whole country. And it is that everyone has seen the windmills that are distributed throughout the Spanish geography and, in certain areas, are already a tourist area.
- Clean energy – Wind energy is another clean energy , almost as much as solar energy and much more than fossil fuels. Wind energy does not contribute to climate change or the greenhouse effect. In fact, it is one of the cleanest renewable energies that exists
- Wind Turbines – Wind turbines , the famous electric windmills, are increasingly modern and efficient and are capable of producing more energy. There is even now an island in Hong Kong whose 100% energy is produced by a single turbine.
- On a small scale – Although it is normal for investments in wind energy to be large-scale and looking for the greatest amount of production, wind energy is also likely to be used at small . However, as we have said, in most countries it is only used to generate electricity at the industrial level.
DISADVANTAGES OF WIND ENERGY
As with solar energy, the disadvantages of wind energy are minimal in comparison but it should be kept in mind, do not become a problem when it is late.
- Situation of wind turbines – One of the main drawbacks facing wind power is the situation of wind turbines. In the first place, the location of these large devices is important, since it must be in an area where the wind blows and where there are no natural or artificial barriers in its path.
- Impact on the landscape – As we have said, wind turbines cause a significant landscape impact . In some cases, it has become a symbol of some areas. In others, it is a strange element in natural and wild areas where such large elements had never been placed.
- Bird migrations – The fact of placing wind turbines of up to 100 meters and with rotors of up to 30 meters, makes the migrations of the birds are altered . Its presence is disturbing for many birds and, of course, many of them end up being sectioned by the large rotating blades of wind turbines.
- Marine wind turbines – To avoid the impact of wind turbines on land, the solution involves placing them inside the sea, with a minimum distance of 3 km inland. But of course, this means triggering investment and increasing maintenance costs (wiring, installation, infrastructure, energy transport …). In addition, the vibrations that occur inside the sea, also affects the marine ecosystem.
ADVANTAGES OF BIOMASS
- Biomass is a renewable source of energy.
- In the responsible processing of biomass into energy, carbon dioxide (CO 2 )
- does not pollute the atmosphere, since new plants absorb all the carbon dioxide released during fuel combustion during the growth process.
- When using fuel derived from biomass, a small amount of atmospheric sulfur oxides (SO) is emitted, even in the case of direct combustion of this fuel. In general, the emission of sulfur oxides when using biofuels of any kind is lower than when using traditional natural fuels (coal, oil, gas).
- Large biofuel power plants are able to operate continuously, unlike solar and wind power plants, which depend on the sun and wind, respectively.
- Methane can be produced in small compost plants. To obtain it, it is not necessary to use exclusively centralized sources. This helps to ensure energy security, as it allows dispersing energy resources, which reduces the risks of natural disasters and the impact of the “human factor”.
- Some plants — sources of woody biomass (rod-like millet – sorghum, in particular) help reduce erosion and form a habitat for wild animals.
DISADVANTAGES OF BIOMASS
- The burning of biomass nevertheless leads to the release of a certain amount of various (depending on the type of biomass used) pollutants. The most common are nitrogen oxides (NO). With direct wood burning, significant amounts of carbon oxides and dust (particulate matter) can be released.
- Uncontrolled procurement of biomass fuel for power plants is harmful to nature.
- Transporting biomass to compost plants or furnaces is accompanied by energy consumption – usually in the form of natural fuels for trucks and trains.
- Biogas production by composting can be accompanied by unpleasant odors. There are also concerns that, without proper control, this process may lead to the multiplication and spread of pathogens.
- The containers in which biogas is stored require regular inspections and certification by qualified and licensed personnel. This may be inconvenient and expensive, but it is the strictest condition for the operation of such containers, ensuring the safety of people living and working near biogas storage facilities. You can read a more detailed article about biomass advantages and disadvantages