Renewable energy is energy that comes from virtually inexhaustible natural sources. They are considered inexhaustible either because of the large amount of energy they contain or because they can be regenerated naturally.
Among the main advantages of renewable energies we highlight the following:
Renewable energies are respectful with the environment and do not pollute. In this sense, they are safer and pose fewer health risks than other sources of non-renewable energy. The more energy generated by clean energies will need to generate fossil energy mes and decrease,…
Thermal energy is the energy released in the form of heat. It can also be called heat energy. In a more technical way we can define thermal energy as part of the internal energy of a thermodynamic system in equilibrium that is proportional to its absolute temperature and is increased or decreased by energy transfer.
The thermal energy can be transformed using a thermal engine (a thermoelectric power plant uses thermal energy to generate electricity); or in mechanical work (for example, a car, airplane or ship engine).
The obtaining of thermal energy can imply an environmental…
In thermodynamics, the internal energy is the total energy contained in a thermodynamic system.
The internal energy is the energy that is needed to create the system. According to this definition, the energy to displace the environment of the system, any energy related to external force fields (potential energy, gravitational energy, etc.) or any energy associated with the movement (for example, kinetic energy) is excluded from the internal energy. .
The internal energy of a system can be modified by exercising a work on it or by heating it (providing thermal energy). If we look…
In general, both photovoltaic solar energy and, above all, solar thermal energy has a very good acceptance in society. However, it is convenient to know the advantages and disadvantages of solar energy to reinforce or contrast our opinion.
When we talk about energy sources, most people are positioned in favor or against a certain type (solar energy, nuclear energy, wind power, etc.). The arguments for positioning are varied: energy efficiency, pollution, safety, cost ... Therefore, we will try to analyze the advantages and disadvantages of solar energy in the most objective way possible.…
In the field of renewable energies, there are other renewable technologies in the development phase. Cellulosic ethanol, geothermal energy from hot and dry rock and marine energy are technologies that can complement traditional photovoltaic solar energy, wind energy or hydropower, for example.
However, these technologies are not yet sufficiently developed or have limited commercialization. Many of these new sources of renewable energy have great potential, but they still have a long way to go in research and development.
There are numerous organizations within the academic…
Geothermal energy is a type of renewable energy on a human scale that is obtained from the heat of the interior of the Earth. Equestrian thermal energy can be obtained without the combustion of any material, it is therefore a form of clean energy without carbon dioxide emissions.
The temperature in the inner layers of the Earth remains constant during the different seasons of the year. Generally the inner layers are hotter than the surface in winter and cooler in summer. This is because the surface layers are heated and cooled more easily according to the laws of thermodynamics.…
The term solar energy refers to the use of the energy that comes from the Sun. It is a type of renewable energy. The energy contained in the Sun is so abundant that it is considered inexhaustible. The Sun takes 5 billion years emitting solar radiation and it is estimated that it has not yet reached 50% of its existence.
Solar energy, in addition to being inexhaustible is abundant: the amount of energy that the Sun pours daily on…
Solar energy allows to take advantage of the energy that comes from solar radiation. One way to take advantage of sunlight is to convert the radiation into electrical energy (photovoltaic solar energy) or thermal energy (solar thermal energy). Photovoltaic solar energy requires a chemical process to obtain a continuous current, while solar thermal energy only requires a thermodynamic process.
The characteristics of solar energy imply certain advantages with respect to other sources of energy. Mainly if the other sources of energy are non-renewable energies that come from fossil fuels.…
The kinetic energy or energy of movement is a form of energy that has a body in motion due to mass inertia. In non-relativistic frames of reference, the kinetic energy is directly proportional to the mass and the square of the velocity. It is the same as the work that needs to be done so that the body goes from the state of rest to the condition in which it is found.
In classical mechanics we make the following considerations:
- A body with mass m that moves at a velocity v has a kinetic energy Ec = (m · v 2 ) / 2.
- If the body…
What is wind power?
Wind energy is a renewable energy whose origin is wind. This energy source takes advantage of the kinetic energy generated by the effect of air currents to transform it into other useful forms for human activities. Historically, wind energy has been used since ancient times to move sail-driven boats or operate mill machinery when moving its blades.
The most common use of wind energy is the generation of electricity. Wind turbines are machines that convert the kinetic energy of wind into electrical energy.
Wind energy is an abundant, renewable,…
The characteristics of solar energy imply certain advantages with respect to other sources of energy.
Although the characteristics are different in photovoltaic solar installations and solar thermal installations, we will treat the disadvantages globally.
Certain disadvantages of solar energy may imply that a solar installation may be unfeasible. The aspects to consider are the following:
- Energy efficiency is poor compared to other energy sources.
- The economic cost compared to other options.
- Performance is a function of the weather.
The first law of thermodynamics was announced by Julius Robert von Mayer in 1841. It is the principle of conservation of energy.
Definition of the first law of thermodynamics: The total energy of an isolated system is neither created nor destroyed, it remains constant. Energy only transforms from one type to another. When one energy class disappears, an equivalent quantity of another class must be produced.
A body can have a certain speed with what has kinetic energy. If it loses speed, this kinetic energy that it loses becomes another type of energy, whether it is potential energy…
Within the history of solar energy, in one form or another, solar energy has always been present in the life of the planet being this imprescidible for the development of life. However, the way in which human civilization has exploited it invented new strategies and tools has undergone a long evolution.
The Sun is indispensable for the existence of life on the planet: it is responsible for the water cycle, photosynthesis, etc. Already the first civilizations realized this and, as civilizations have evolved, they have also evolved techniques to harness their energy. At the beginning they…
The solar thermal energy consists of the use of the energy coming from the Sun to transfer it to a medium that carries heat, generally water or air.
Among the different applications of solar thermal energy there is the possibility of generating electrical energy. The current technology allows heating water with solar radiation to produce steam and then obtain electrical energy.
Although the principle of operation is very similar there are two main applications of solar thermal energy:
- Use of solar thermal energy in homes and small installations…
Wind energy is a source of energy that is becoming very popular in many countries of the world. The advantages associated with the use of wind energy (renewable energy, clean, respectful with the environment, etc.) are helping a lot to its growth and implementation in many countries.
However, the disadvantages of wind power are also notable and must be considered before investing in a wind power plant. Sometimes the contrast between advantages and disadvantages of solar energy or other sources of energy can vary from one place to another.
In this article we analyze the…
The bioclimatic architecture enters what is called passive solar energy. This type of architecture uses natural elements of the place (sun, wind, water, soil and vegetation) to achieve thermally efficient buildings capable of satisfying thermal comfort requirements, regardless of the use of air conditioning systems.
The bioclimatic approach is related to the principle of self-sufficiency and the realization that the main phenomena that negatively affect the environment are caused by the consumption of large amounts of non-renewable energy, fossil fuels or nuclear energy. Construction…
In physics, in particular in thermodynamics, heat is defined as the contribution of transformed energy as a result of a chemical or nuclear reaction and transferred between two systems or between two parts of the same system. This energy is not attributable to a job or a conversion between two different types of energy. Heat is, therefore, a form of transferred energy and not a form of energy contained as internal energy.
As the energy is exchanged, the heat is measured in the International System in joules. In practice, however, it is often still used as the unit of measurement of calories,…
Hydropower is a source of renewable energy or alternative energy. This renewable energy exploits the transformation of gravitational potential energy, possessed by a certain mass of water at a certain elevation, in kinetic energy to overcome a certain difference in height. The mechanical energy obtained can be used directly to rotate the shaft of a turbine or in some application or machine that works using hydropower. The most common is to use this kinetic energy to generate electrical energy. In this case, we talk about hydroelectric power.
In hydroelectric power, the kinetic energy…
Geothermal energy is a renewable energy obtained from the heat stored inside the Earth. Thanks to the laws of thermodynamics, thermal energy is transferred from the interior of the Earth to a fluid. In this way, energy is transported in the form of internal energy.
Geothermal energy is basicaly based simply on taking advantage of the fact that the subsoil temperature is warmer than on the surface, in winter, and instead cooler, in summer. This is a consequence of the fact that the surface layers of the Earth are heated and cooled much more easily than the interior, which is maintained…
Non renewable energies are the methods of obtaining energy through a source of exhaustible energy. The concept of non-renewable energy is taken into account at the scale of human life, since certain processes, such as the accumulation of carbon, have taken up to five hundred million years.
In general, non renewable energy is what consumes some type of fuel (oil, coal, uranium ...). While renewable energy uses other types of energy resources (solar radiation, the kinetic energy of the wind, the force of water, the movement of the tides, etc.). Although properly speaking some fuels, in…
In the design of passive solar buildings, windows, walls and floors are made to collect, store and distribute solar energy in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design because it does not involve the use of mechanical and electrical devices.
The key to designing a passive solar building is to make the most of the local climate by performing a precise site analysis. The elements to be considered include the placement and size of the window, and the type of glazing, thermal insulation, thermal mass and shading. Passive solar…
The watt (symbol: W) is the power unit of the International System, it is the amount of energy in joules that is converted, used or dissipated in one second. It is a derived unit that takes its name from the engineer, inventor and constructor of Scottish instruments James Watt, for his contribution to the development of the steam engine, which was one of the triggers of the beginning of the Industrial Revolution.
The watt unit was adopted by the Second Congress of the British Association for the Advancement of Science in 1889, which meant its international recognition as a power unit,…
Hybrid solar energy systems are hybrid energy systems that combine the solar energy of a photovoltaic system with another source of energy that generates energy. A common type is a hybrid photovoltaic diesel system, which combines solar photovoltaic (PV) and diesel generators, or diesel generator sets, since PV has only a marginal cost and is treated with priority in the network. Diesel generator sets are used to constantly fill the gap between the current load and the actual power generated by the photovoltaic system.
Since the solar energy fluctuates and the generation capacity of…
Solar thermal energy is a way to harness the heat of solar energy from to get heat. Of the different techniques to convert solar radiation into thermal energy, in this section, we explain high-temperature solar thermal energy.
We refer to high-temperature solar thermal energy to those solar systems that use solar collectors that work at temperatures above 500ºC. In this type of installations, once the solar radiation has been transformed into heat energy, the next objective is to transform this heat into electrical energy.
Geothermal energy is a long-term source of energy worldwide. With the geothermal energy stored in the top three kilometers of the Earth's crust, theoretically, the current energy demand could be covered for more than 100,000 years. However, only a small part of this energy is technically usable and the effects on the earth's crust during extensive heat dissipation are not yet clear.
When geothermal energy is used, a distinction is made between direct use, that is, the use of heat in itself, and indirect use, the use for conversion into electricity in a geothermal power plant. With the…
Hydropower is the electric power produced in a hydroelectric power station from a current, vertical or horizontal, of a river. In other words, it is electricity (electrical energy) obtained from hydraulic energy (mechanical energy of water in movement of rivers, lakes and marshes).
The difference between hydroelectric and hydraulic energy is that hydraulic energy can be used to generate electrical energy but also to obtain energy of another type, for example, mechanical energy. While hydropower refers only to the use of hydropower to obtain electric power or electricity.
Thermodynamics is the branch of classical physics that studies and describes the thermodynamic transformations induced by heat and work in a thermodynamic system, as a result of processes that involve changes in the temperature and energy state variables.
Classical thermodynamics is based on the concept of macroscopic system, that is, a portion of physical mass or conceptually separated from the external environment, which is often assumed for convenience that is not disturbed by the exchange of energy with the system. The state of a macroscopic system that is in equilibrium conditions…
The applications of photovoltaic solar energy are many and varied. In this field, they include from large power generation plants through photovoltaic panels, to small solar calculators.
A first way to classify the applications of photovoltaic solar energy is to distinguish the applications connected to the electrical network and the isolated installations.
The use of photovoltaic panels in isolated buildings is very useful since the investment needed to place solar panels on the roof of a farm, a chalet in the mountain or in a hotel in a secluded spot, is much less than what it…
A solar accumulator is a device that allows to store the solar energy captured by the solar panels. The objective of the compilers is to take advantage of the energy obtained at the time when solar energy can not be produced (during the night, cloudy days, etc.)
For this we distinguish two types of solar compulators:
- Thermal solar compulators.
- Electric solar compulators.
Solar thermal compulators store heat. This type of acomulator is related to thermal energy installations. In these installations the solar…
Nuclear energy is the energy that is obtained from the division (nuclear fission) or from the union (nuclear fusion) of an atom. Despite the existence of a large number of applications related to nuclear energy (medicine, industry, transport, etc.), the main application of this technology is the generation of electrical energy.
Electricity of nuclear origin is generated in nuclear power plants. At present, all nuclear power plants operate through nuclear fission reactions. The nuclear fuel they use is usually uranium or plutonium (by an artificial process). Because…
Low-temperature solar thermal installations are considered those installations of solar thermal energy that provide useful heat at temperatures below 65 ° C through solar energy.
A low-temperature solar thermal installation consists of solar collectors, two water circuits (primary and secondary), heat exchanger, accumulator, expansion vessel and pipes.
The circulation of water inside the circuits can be obtained by thermosiphon, taking advantage of the density difference of the water at different temperatures or by means of a circulation pump. Although with a circulation…
Geothermal energy is a type of renewable energy. It is considered renewable energy because it does not consume resources and is practically inexhaustible.
Its principle of operation is based on the use of heat inside the Earth. One of the most used techniques to take advantage of the internal energy of the rocks is to build wells of about 150 meters through which a fluid circulates. The fluid falls with a low temperature, at the bottom through a thermodynamic process it is heated and goes up with the thermal energy acquired to the surface.
It is a new technology…
Active solar energy classifies technologies related to the use of solar energy that use mechanical or electrical equipment to improve performance or to process the energy obtained by converting it into electrical or mechanical energy. These equipments can be fans, water pumps, etc.
In contrast, solar systems that do not use these devices are classified as passive solar energy systems. Examples of active solar energy
The applications of active solar energy can be classified into two types:
- Thermal solar energy
- Photovoltaic Solar Energy
In thermodynamics, an isothermal process is a thermodynamic transformation at constant temperature, that is, a variation of the state of a physical system during which the temperature of the system does not change with time. Devices called thermostats can maintain a constant temperature value.
The isothermal transformation of a perfect gas is described by Boyle's law which, in a pressure-volume diagram (or Clapeyron's plane), is represented by a branch of the equilateral hyperbola. Isotherm of a perfect gas Calculation of heat and work exchanged
For isothermal gas…
Biomass energy is biological energy, and allows biological entities (living beings) to move, to have brain activity and food production and the synthesis of biological tissues.
Biomass energy is continuously retransformed cyclically. The typical bioenergetic cycle of plants is called the "Calvin cycle". The bioenergetic cycle of living beings is called the "Krebs cycle". In these cycles the transformation of sugars occurs in other carbohydrates, the purpose of this transformation is the synthesis of very high energy concentration molecules, such as ATP and ADP. Technological…
The efficiency of photovoltaic cells is one of the elements that determine the production of a photovoltaic solar energy installation. The other factors that determine the performance of a solar plant are latitude and climate.
The conversion efficiency value of a photovoltaic cell depends on several factors. When we refer to conversion efficiency, we refer implicitly to the thermodynamic efficiency, to the separation efficiency of the load carrier, to the reflectance efficiency and to the values of conduction efficiency. These parameters are difficult to measure…
The geothermal heat pump is an air conditioning system for buildings that exploits the heat exchange with the superficial subsoil, by means of a heat pump. Since the heat in the subsoil comes largely from the interior of the Earth, geothermal energy of low enthalpy is classified as a source of renewable energy, although the heat pump itself consumes electricity, generally produced from other sources of energy (for example, fossil fuels).
The heat pump allows the exchange of heat between a "source" at a lower temperature than the "well", or the point where the heat is introduced. In a…
Fossil energy is the energy that comes from the combustion of fossil fuels.
It is a source of non-renewable energy because it is not an inexhaustible energy source nor regenerates at the same rate at which it is consumed.
Fossil fuels are formed from organic substances that have accumulated in the ground. These substances can be the remains of plants, animals and other living things. Over the years, millions of years, they undergo certain physical and chemical transformations until they reach the point where they become components of which it is easy to convert them into energy:…
Thermosolar energy is a technology to generate electricity or electricity by thermal energy from the Sun (solar heat). It is a type of solar thermal energy. Solar thermal energy is characterized by using solar radiation to heat a fluid. This hot fluid (usually water) can be used for many applications such as heating or hot water (DHW). But another application that can be given is the generation of electric power.
This type of energy is also often called thermoelectric power.
This process of electricity generation takes place in the so-called thermoelectric solar or solar thermal…
Solar radiation is the radiant energy emitted in the interplanetary space of the Sun. This radiation is generated from thermonuclear fusion reactions that occur in the solar nucleus and produce electromagnetic radiation at several frequencies or wavelengths, which it then propagates in space at the typical speeds of these waves. This spread allows you to bring solar energy with them.
The solar constant is the amount of energy received in the form of solar radiation per unit of time and unit of surface, measured in the outer part of the Earth's atmosphere in a plane perpendicular to the…
One kilowatt (kw) is a power unit in current use, equivalent to 1000 watts (w).
One watt (w) is a power unit of the international system equivalent to one joule per second.
If we express the watt in units used in electricity, we can say that a watt is the electric power produced by a potential difference of 1 volt and an electric current of 1 ampere (1 volt ampere).
Frequently the watt hour (Wh) is also spoken as an energy unit. The watt hour is a practical unit of energy equivalent to the energy produced by a power of one watt for one hour. Common errors related…
The photovoltaic effect is the photoelectric effect characterized by the production of an electric current between two pieces of different material that are in contact and exposed to light or, in general, to electromagnetic radiation.
The photovoltaic effect consists of converting sunlight into electrical energy by means of photovoltaic cells. These cells are semiconductor devices made from pure silicon with the addition of impurities of certain chemical elements. Photovoltaic cells are capable of generating electricity in direct current, using solar radiation as a source.
Photovoltaic solar energy consists of the direct transformation of solar radiation into electrical energy. This type of energy is often referred to directly as photovoltaics.
This transformation in electrical energy is achieved by taking advantage of the properties of semiconductor materials through photovoltaic cells. The base material for the manufacture of photovoltaic panels is usually silicon. When sunlight (photons) hits one of the faces of the solar cell, it generates an electric current. This generated electricity can be used as an energy source.
Definition of temperature: The temperature is the thermodynamic magnitude that shows the thermal energy of one body in relation to another.
Although the definition of temperature is simple and concise, you can explain what the temperature is in a more extensive way: What is the temperature?
Temperature is a physical quantity of matter that quantifies the common notions of heat and cold. The objects of low temperature perceive them cold, while objects of higher temperatures we consider them warm or hot. This physiological sensation of cold and heat is generated…
A solar storage tank is a reservoir that separates the solar energy supply from the energy collection. That is to say, it is frequent, especially in the field of solar energy, that the electrical power that one wants to use does not correspond to the electric power that is being obtained at a certain moment. For example, hot water may be required at night, but solar radiation is not available to heat it.
To do this, the accumulator stores thermal energy from the solar collectors. It can be considered as a battery that stores heat energy.
When the system needs, for…
For the conversion of fossil energy into electrical energy, the technology of a thermal power plant is often used. At the moment in which a thermal power station is fossil fuels fossilized from a source of non-renewable energy generation.
A thermal power plant (or thermoelectric plant) is a plant that generates electricity by transforming heat. Historically heat energy is converted into electricity by transferring heat to a working fluid and then transforming the energy of this fluid into mechanical energy. Finally, mechanical energy is transformed into electricity. The…
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially, using the energy of solar radiation.
Photosynthesis occurs in plants, algae, and some groups of bacteria, but not in archaea. Photosynthetic organisms are called "photoautotrophs," but not all organisms that use light as an energy source effect photosynthesis, since "photoheterotrophs" use organic compounds, not carbon dioxide, as a carbon source. In plants, algae and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. photosynthesis is crucial…
A solar panel is a device to take advantage of solar energy. It can also be called a solar module.
Photovoltaic solar panels contain a set of solar cells that convert light into electricity. It is called solar because the sun is one of the strongest energy sources for this type of use. Solar cells are sometimes called photovoltaic cells, and photovoltaics literally means "light-electricity". Solar cells have the photovoltaic effect to absorb the sun's energy and cause electrical current to flow between two charged layers in the opposite direction.
The denomination of solar panel…
Fossil fuels are often spoken of as a type of negative, polluting energy, harmful to the environment. Fossil fuels are considered a non-renewable energy source due to the difficulty of regeneration.
Currently, fossil fuels are the most widely used energy source in the world. It is used to generate electrical energy but above all it is also used to generate mechanical energy (cars, heat engines, etc.)
The theory that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the earth's crust for millions of years was first introduced…
Autonomous photovoltaic installations are those installations that are isolated from the electricity grid. All the electrical energy generated by the solar panels is consumed directly.
This type of photovoltaic installations are designed for the cases in which the cost of maintenance and installation of power lines is not profitable. For example, this would be the case of mountain refuge.
The main element of autonomous photovoltaic installations is the photovoltaic panel. The photovoltaic panel is responsible for transforming solar radiation into electrical energy…
A thermodynamic property is a characteristic or a particularity that allows the changes of the work substance, that is to say, changes of energy.
The thermodynamic properties can be classified as intensive and extensive. They are intensive those that do not depend on the amount of matter of the system (pressure, temperature, composition). Extensive ones depend on the size of the system (mass, volume). Thermodynamic variables
The thermodynamic variables are the magnitudes…
Passive solar energy is based on the use of solar energy without the need to use external support mechanisms. By these mechanisms we refer to the use of electric motors to orient solar panels or similar systems.
The objective is to obtain personal thermal comfort. Personal thermal comfort is a function of personal health factors (medical, psychological, sociological and situational), ambient air temperature, average radiant temperature, air movement (thermal sensation, turbulence) and relative humidity (which affects human evaporative cooling).
To use passive solar energy…
We refer to the photovoltaic effect in everything related to obtaining energy through the action of light.
The most used light source for photovoltaic installations is that coming from the Sun, that is, solar energy. Although there are small devices, such as calculators, that can work with artificial light. Photovoltaic solar energy
Solar photovoltaic energy is a methodology for obtaining electrical energy thanks to photoelectric cells. It is a renewable energy since its energy source, the Sun, is considered inexhaustible.
Photoelectric cells are the main component…
One of the applications of solar thermal energy is the obtaining of sanitary hot water (DHW). Solar collectors capture the energy of solar radiation to increase the temperature of a fluid.
Domestic hot water (DHW) is water intended for human consumption (potable) that has been heated. It is used for sanitary uses (bathrooms, showers, etc.) and for other cleaning uses (washing dishes, washing machine, dishwasher, floor scrubbing). In terms of energy, the DHW is an important component to take into account, since it represents between 25 and 40% of the energy consumption of homes.
Geothermal power plants are the plants responsible for converting geothermal energy into electricity. A geothermal plant is a facility where electricity is generated by geothermal energy.
Geothermal energy is the thermal energy contained inside the Earth. These facilities perform a thermodynamic exchange at a certain depth of the terrestrial layers to heat a fluid. This heat is used to generate electricity. Because the heat inside the Earth is inexhaustible, it can be said that this form of electricity generation is a source of renewable energy.
The Francis turbine is a hydraulic turbine used in hydropower installations with a considerable height of fall.
The Francis turbine is a type of hydraulic turbine built by British-American engineer James Bicheno Francis. The function of the Francis turbine is mainly to generate electricity with the help of a generator. Francis turbines have a high utilization capacity of more than 90% and a wide range of activities compared to the height (building drop) of the fluid flowing through the turbine. This is particularly emphasized in water where it achieves optimum performance in a building…
Fossil fuels are non-renewable energy resources because they require millions of years for their formation in a natural way. Due to their high calorific power they are useful energy sources to generate thermal energy and their use has allowed the great economic and demographic growth linked to the industrial revolution of the 19th century. Although now they are fundamental for our economy. In 2007, the combustion of coal, oil and natural gas accounted for 86.4% of the world's primary energy. However, its combustion is one of the main sources of atmospheric pollution and global warming, which…
In this section we intend to answer the main questions related to solar energy.
Generally, these are general topics that could be located in several sections of the web. Our intention is to expand this section in the future to publish generalist articles and curiosities of nuclear energy.
Most of the questions are focused on small solar installations, comparative with solar thermal energy and photovoltaic solar energy.
In the future we will also answer on more oriented questions in the field of physics: thermodynamics, forms of energy, mechanical energy, potential energy,…
What is entropy? Entropy (S) is a thermodynamic quantity originally defined as a criterion for predicting the evolution of thermodynamic systems.
Entropy is a function of extensive character state. The value of entropy, in an isolated system, grows in the course of a process that occurs naturally. Entropy describes how a thermodynamic system is irreversible.
The meaning of entropy is evolution or transformation. The word entropy comes from the Greek. Entropy in the world of physics
In physics, entropy is the thermodynamic magnitude that allows us to calculate the…
The flat plate solar collector is a type of solar thermal panel whose objective is to transform solar radiation into thermal energy. This type of solar collector has a good cost / effectiveness ratio in moderate climates and adapts correctly to a large number of applications of solar thermal energy (heating of sanitary water, heating of swimming pools, support for heating, preheating industrial fluids , etc.).
We can distinguish two basic types of flat plate solar collectors, depending on the configuration of the absorber: the "grid type" parallel, in the vertical and horizontal…
Hydropower is a source of renewable energy that uses water to generate energy. Normally, it uses the potential energy of water at a certain height to generate turbines and with them, electricity.
The mechanism of operation is to take advantage of the potential energy of water at a certain height, it is dropped to convert this energy into kinetic energy. With the kinetic energy of water a turbine that is connected to an electric generator is activated.
Generally, the installations responsible for hydroelectric production are hydroelectric power plants. Usually these facilities…
Solar thermal energy uses solar radiation to increase the internal energy of an element. Said in one way: to heat an element. Normally a liquid is heated to be able to transport this energy more easily to the place where you want to take advantage of it.
In single-family homes it is very common to see solar collectors. The function of these collectors is to heat sanitary hot water for domestic use or for heating. They are generally support systems but allow considerable financial savings. The installation of these solar collectors is very popular in certain areas due to its low installation…
The electric current generated by a photovoltaic solar energy installation can be poured into the electricity grid as if it were a power plant. The consumption of electricity is independent of the energy generated by the photovoltaic panels. In these cases, the user continues to buy the electric energy consumed by the distribution company at the established price and also owns an electric power generation facility.
The most usual powers measured in vations are 2.5 and 5 kilowatts (kw) or multiples of 5 to 100 kilowatts (kw). There are larger solar installations, but they…
A forced circulation for solar water heater is an installation in which the water circulates inside the circuit driven by a pump. With forced circulation system, the movement of water in the closed circuit is forced by a pump. This feature makes a big difference with respect to sanitary hot water installations with thermosyphon. In this way, it artificially moves the hot water not to the highest point of the closed circuit, but it does so from the solar collectors down to where the accumulator is located.
In many occasions it is not viable to install solar thermal equipment…
The generation of fuel through solar energy is a technique based on generating chemical reactions using solar radiation. These chemical processes allow the generation of energy that would otherwise come from a source of fossil fuel or nuclear energy.
A great advantage of the generation of solar fuels is that they can be transported and stored easily. However, adding a step in the generation of electric power (fuel generation) implies a reduction in efficiency: adding an additional step between the storage of energy and the production of electricity drastically decreases the…
Tidal energy is the energy obtained from the movements of water caused by the tides. It represents a source of renewable energy since it uses an inexhaustible resource.
The tide, the rhythmic rise and fall of sea level caused by the gravitational action of the moon and the sun, generally has a width (difference between high tide and low tide) of less than one meter, but in some areas, due to the particular configuration of the site, the difference in height can reach high values, interesting for the exploitation and production of energy, which is currently predominantly electrical. In…
A turbine is a turbomachine that converts the flow energy of a fluid (liquid or gas) into mechanical energy by means of a system of rotating blades. This mechanical energy can be used to power another machine or an electric generator.
The turbine name was proposed by Claude Burdin during an engineering contest in 1828. This name comes from the Latin turbine, which means Foucault current.
A simple turbine consists of a single rotor with blades, which provide energy exchange with the flow. The first examples of turbines are wind turbines and water mills, that is, for wind…
Solar collectors are the elements that capture solar radiation and convert it into thermal energy, into heat. It is a type of solar panel designed for use in solar thermal installations. It is also known as a solar collector.
The function of solar thermal energy is to take advantage of solar energy to obtain heat, to heat a fluid. Unlike photovoltaic solar energy whose function is to generate electricity.
Solar collectors are those with flat plates, evacuated tubes and absorber collectors without protection or isolation. The flat (or flat plate) collection…
Photovoltaic modules or solar panels are devices that are used to capture the energy of the sun's light. Photovoltaic solar panels contain a set of solar cells that convert light into electricity. It is called solar because the sun is one of the strongest energy sources for this type of use. Solar cells are sometimes called photovoltaic cells, and photovoltaics literally means "light-electricity". Solar cells have the photovoltaic effect to absorb the sun's energy and cause electrical current to flow between two charged layers in the opposite direction.
Currently, the costs associated…
An electric generator is a device designed to produce electricity from a different form of energy.
The different forms of energy, which are transformed into electricity, are usually mechanical energy, chemical energy, photovoltaic energy or directly thermal energy.
Depending on their characteristics, there are several types of electric generators. The analysis of these generators is not limited only to the generators used in photovoltaic solar energy, but we will make a brief review of all types of electric generators. Photovoltaic generators
Geothermal energy is that energy that can be obtained by man through the use of heat from the interior of the Earth. This type of energy has many applications. One of these applications is the generation of electric power.
The generation of electricity from geothermal energy is a good complement for hydroelectric plants, which also has the advantage that it is constant throughout the year. Geothermal plant
Geothermal power plants are the plants responsible for converting geothermal energy into electricity. A geothermal plant is a facility where electricity is generated…
Natural gas is a source of fossil energy, like coal or oil, it is constituted by a mixture of hydrocarbons, molecules formed by carbon and hydrogen atoms. Its calorific value varies greatly according to its composition, but the highest are between 8,500 and 10,200 kilocalories per cubic meter of natural gas.
Natural gas is a primary energy, or that can be obtained directly without transformation. The other primary energies are solar energy, coal and oil. It is the cleanest fossil energy in terms of waste and atmospheric emissions, and the most efficient fuel for obtaining electricity…
According to the first law of thermodynamics, every process that occurs in a given system must satisfy the principle of conservation of energy, including the flow of heat.
states, in other words, that any process whose sole purpose is to create or destroy energy, is impossible, that is, it denies the existence of a first-class perpetual motion machine.
However, the first law does not tell us anything about the…
Enthalpy is a term linked to the field of thermodynamics. The enthalpy symbol is H.
Enthalpy is also known as absolute enthalpy or amount of heat.
We define enthalpy as a physical quantity defined in the field of classical thermodynamics so that it measures the maximum energy of a thermodynamic system theoretically capable of being eliminated from it in the form of heat or thermal energy.
Enthalpy is particularly useful in the understanding and description of isobaric processes: the constant pressure, the enthalpy change are directly associated with the energy received…
Coal is a fossil fuel that is used to obtain fossil energy through its combustion. The thermodynamic properties of coal allow obtaining a large amount of heat energy during its combustion process.
Coal is a natural resource limited. The generation of coal is a process of several million years, while the consumption of this energy resource is very fast. For this reason, coal is considered a non-renewable source of energy.
Coal is a sedimentary rock of organic origin, black or dark brown. It is used mainly as a fossil fuel because of its high calorific value…
The function of a solar thermal installation is to take advantage of solar energy to generate heat. The solar panels of these facilities capture the heat of the solar radiation that falls on them to heat a fluid. The different ways to take advantage of this hot fluid allows us to use this type of renewable energy in multiple applications.
A solar thermal installation consists of:
- Solar collectors
- Primary and secondary circuits
- Heat exchanger
- Accumulator, pumps
- Glass of expansion
- Main control panel.
The constant price increases in electricity rates are reflected in the monthly bills of our home and therefore, more and more people are looking for alternatives to electricity and natural gas in order to save a few euros at the end of the month . One of these alternatives that has been implemented for a few years in Spain is self-consumption from solar panels .
With the installation of solar panels and the use of solar radiation, it is possible to generate electricity and / or heat in the home in a clean and renewable…
Thermodynamics is mainly based on a set of four laws that are universally valid when applied to systems that fall within the constraints implicit in each.
The first principle that was established was the second law of thermodynamics, as formulated by Sadi Carnot in 1824. The 1860 already established two "principles" of thermodynamics with the works of Rudolf Clausius and William Thomson, Lord Kelvin. Over time, these principles have become "laws." In 1873, for example, Willard Gibbs claimed that there were two absolute laws of thermodynamics in his graphical methods in fluid thermodynamics.…
A photovoltaic power plant or a photovoltaic power station is a set of facilities designed to supply electricity to the grid through the use of large-scale photovoltaic systems. The function of the photovoltaic power station is to capture and transform solar radiation into electricity.
A photovoltaic power plant is a power plant consisting of photovoltaic modules and an inverter. The photovoltaic panels are in charge of transforming the solar radiation, into electrical energy of direct current. The inverter is the electronic equipment whose function is to convert the direct…
Solar irradiation is the magnitude that measures the energy per unit area of incident solar radiation on a surface placed in a well-specified place and time range.
The solar irradiation in the terrestrial surface is, from the technical point of view, the addition in a determined interval of the solar radiance filtered by the interposition of the atmosphere.
The value of solar irradiation on the surface depends on the time of year, latitude, local climatology and times of day. Origin of solar irradiation
The origin of electromagnetic radiation from the Sun.…
An inverter is an electronic device. The function of the inverter is to change a DC input voltage to a symmetrical AC output voltage, with the magnitude and frequency desired by the user. The inverters use in a great variety of applications, from small power supplies for computers, to industrial applications to control high power. The inverters are also used to convert the direct current generated by photovoltaic solar panels, accumulators or batteries, etc., into alternating current and thus be able to be injected into the electrical network or used in isolated electrical installations.…
An inverter is an electronic device. The function of the inverter is to change a DC input voltage to a symmetrical AC output voltage, with the magnitude and frequency desired by the user. The inverters use in a great variety of applications, from small power supplies for computers, to industrial applications to control high power. The inverters are also used to convert the direct current generated by photovoltaic solar panels, accumulators or batteries, etc., into alternating current and thus be able to be injected into the electrical network or used in isolated electrical installations.
A hybrid solar panel (more correctly defined as a PVT collector, an acronym P hoto V oltaic and T hermal) is a device that allows the conversion of the energy radiated by the sun partly into electrical energy and partly into thermal energy through the combination of the effect of a photovoltaic module and a thermal solar panel (photovoltaic cogeneration).
Therefore, a hybrid solar panel is composed of a photovoltaic collector to which a heat exchanger is associated, capable of heating a fluid thanks to the part of the solar radiation not converted into electrical energy. Origin…
The Stirling engine was invented in 1816 by Robert Stirling, a Scottish priest. The goal was to get a less dangerous engine than the steam engine.
The operation of the Stirling engine is based on the expansion and contraction of a gas that can be helium, hydrogen, nitrogen or air. This gas is forced to cycle cyclically from a cold source where it contracts to a hot source where it expands. It is considered as a thermal engine (thermodynamic engine) due to the presence of a temperature gradient between the two thermal sources.
Originally, the Stirling engine was conceived as an…
The batteries in a photovoltaic solar energy system is to accumulate the energy produced by the photovoltaic panels during the hours of Sun to be able to use it at night or on cloudy days.
The use of batteries also allows to provide a higher current intensity than a functioning photovoltaic panel can offer. This would be the case if several electrical appliances were used at the same time.
A battery consists of small 2V accumulators integrated in the same element; Has direct current at 6, 12, 24 or 48V. The accumulator is the cell that stores energy through an electrochemical…
In electricity, the rated voltage of an electrical device is the voltage that must not be exceeded in normal operation. The nominal adjective is because that tension usually serves to characterize the device, to name it. The nominal value indicates the theoretical or ideal value of anything that can be quantified, as opposed to the real value, which is what is obtained in a given measurement.
Another definition of rated voltage: The rated voltage is the specific potential difference for which a device or installation is designed.
As it is a nominal value it implies that the voltage…
A thermodynamic process is the evolution of certain properties, which are called thermodynamic properties, in relation to a particular thermodynamic system. In order to study a thermodynamic process, it is required that the system be in thermodynamic equilibrium at the initial and final point of the process; that is, that the magnitudes that undergo a variation when passing from one state to another must be completely defined in their initial and final states.
In this way thermodynamic processes can be interpreted as the result of the interaction of one system with another…
Biofuels are fuels obtained from biomass (agricultural crops such as palm oil, sugar cane, soybeans, etc.) or from organic waste. The fuel generated is a liquid fuel that can be used in the engines of vehicles.
This energy source is considered non-renewable energy because the generation and recovery time of the fields is less than the consumption time.
The biofuels generated can be of two types:
- Bioethanol, a substitute for gasoline, produced from sugarcane, beet, corn, wheat and oats.
- Biodiesel, a substitute for diesel, produced by plants such as sunflower,…
In electronics, a photoelectric cell or a photovoltaic cell is an electrical / electronic device that converts the incident energy of solar radiation into electricity through the photovoltaic effect. Photovoltaic cells are the basic components of photovoltaic modules, which are solar panels capable of generating electrical energy from solar radiation. It is therefore the essential basic element for this type of renewable energy.
Compounds of a material that has a photoelectric effect absorb photons of light and emit electrons. When these free electrons are captured, the result is an…
After the repeal of the "Sun Tax", a new regulation has been promoted for producers and self-consumers of photovoltaic solar energy. In this article we will review the keys of this new legislation and we will reveal what is the ideal light rate for self-consumers of photovoltaic solar energy. The rate of self-consumers
Many people mistakenly think that once the solar panels are installed, it is never necessary to be connected to the electricity grid. Nothing is further from the reality, since to make this possible it is necessary…
The Pelton turbine is a type of turbine used in the hydropower industry within the field of renewable energy.
A Pelton turbine is a hydraulic turbine of the impulse type used in hydroelectric power plants with high vertical height. It was Invent to by Lester Allan Pelton in the 1870s and Amend significantly by other inventors beyond late 1800. The Pelton turbine is a further development of traditional water wheel. The Pelton turbine transforms the hydropower into the impulse of one or more jets of water at…
A solar concentrator is a concentration system of solar energy that is used to convert solar energy into thermal energy. Its operation is based on the exploitation of the reflection of the solar rays obtained through reflective surfaces (substantially of mirrors), in order to concentrate on a receiver of contained size. Similar to a magnifying glass focusing its light on a point, the concentrators reflect sunlight by means of an arrangement of mirrors aligned towards a lens capable of capturing that energy for its use.
In general, heat is converted into mechanical energy by means of…
Fracking, or hydraulic fracture, is an Anglo-Saxon term that is used to refer to a technique to increase the extraction of fossil fuels natural gas and oil from soil.
Hydraulic fracturing or geotechnical fracking is the exploitation of the pressure of a fluid, typically water, to create and then propagate a fracture in a layer of rock in the subsoil. Fracking is carried out after a drilling in a rock formation containing hydrocarbons (oil or natural gas). The objective is to increase the permeability. Improving permeability improves the production of oil or gas contained in the subsoil…
The Sun is a star around which the Earth turns.
It has an approximate diameter of 1,400,000 km and a mass of 1.99 × 1033 g.
The Sun revolves around itself. However, since it is constituted by a large mass of gases, the different regions do not rotate in solidarity, but they do so at different speeds, which depend on latitude.
The Sun, and with it the entire solar system, moves towards a point in the firmament located in the constellation of Hercules at a speed of about 19 km / s. This is because the Sun has a movement of translation around the galactic center, like…
The parabolic cylinder solar collector is another type of solar thermal collector. This type of solar panel used in solar thermal installations uses parabolic cylinders to concentrate all the solar radiation in a point. Instead of heliostats, this type of collector employs parabolic trough mirrors. For the focus of the parabola passes a pipe that receives the concentrated rays of the Sun, where the fluid is heated, usually a thermal oil. Currently the fluid reaches temperatures close to 400º C.
Until recently, the use of thermal solar CCP concentration systems was restricted to…
The generation of biofuels, a priori, represents several advantages with respect to obtaining fossil fuels used to obtain fossil energy. The main advantage is that the regeneration of resources is not millions of years as it happens with coal, oil or natural gas. Anyway, the regeneration of biofuels is not fast enough to be considered a renewable energy source either. They are considered, then, a non-renewable source of energy.
On the other hand, biofuels continue to be an indirect way of harnessing solar energy. In this case, solar energy is exploited thanks to the photosynthesis of…
A solar furnace is an optical system to provide concentrated solar radiation. The concentrated energy of sunlight can be used for simple heating of a material, aging experiments of plastics or paints, endothermic chemical reactions or for charging experiments with mechanical or electrical components.
The solar furnace system is widely used in solar thermal power plants.
The principle of the solar furnace is also used to build cheap solar solar cookers, and for solar water pasteurisation. Solar furnace can be used to supply a Stirling engine, as well.
The difference between…
Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the limits of the laws of thermodynamics.
Chemical thermodynamics involve not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods for the study of chemical questions and the spontaneity of processes.
The structure of chemical thermodynamics is based on the first two laws of thermodynamics. From the first law of thermodynamics and the second law of thermodynamics, four equations…
Geothermal energy is the discipline of Earth Sciences that studies the set of natural phenomena involved in the production and transfer of heat or thermal energy from within the Earth.
In a broad sense, the geothermal concept can also be extended to the study of other planets. Its principles are exploited at a technological level in the production of electricity and cogeneration through geothermal power plants from the associated geothermal energy. The origin of earth's heat of geothermal
The heat of the Earth's core was originally generated during the accretion of the…
Thermal temperature is the absolute measure of temperature and is one of the main parameters of thermodynamics. Its unit of measure in the international system of measures is the Kelvin.
This is an "absolute" scale because it is the measure of the fundamental property of temperature: its zero value, or absolute zero, is the lowest possible temperature. There is nothing that can have a temperature below absolute zero. The absolute zero of the thermodynamic temperature, transformed in the Celsius scale would be equal to 273,5ºC. This characteristic is defined by the third law of thermodynamics…
The greenhouse effect is the process by which the atmosphere of a planet passes solar radiation from the Sun, but instead prevents or hinders the thermal energy output of the planet.
It is called greenhouse effect due to the similarity with the operation of the greenhouses that are able to retain the heat inside. The operation is not exactly the same, but it is very similar. The difference is that the greenhouse uses the glass and not the gases in the atmosphere to retain heat. That is why this natural phenomenon has been called the greenhouse effect.
When we talk about the greenhouse…
At the end of the 17th century, the Earth was conceived as a molten mass with a solid crust as a result of its cooling. It was not until the 19th century that the first calculations of the age of the Earth based on its thermal evolution were drawn up, and the term geothermal was first defined as the scientific discipline that studies earth's heat, origin of this heat, distribution and use.
Precisely, the use of this thermal energy is what has led to the development of geothermal energy. Geothermal energy allows us to take advantage of the heat energy inside the Earth in different applications,…
A thermodynamic system is a portion of the material space, separated from the rest of the thermodynamic universe (that is, from the external environment) by means of a real or imaginary control surface (or edge), rigid or deformable.
A thermodynamic system can be the seat of internal transformations and exchanges of matter and / or energy with the external environment (that is, everything external to the system that interacts with it). Classification of thermodynamic systems
Within thermodynamics there are three main types of thermodynamic systems: open, closed and isolated.…
The installation of large photovoltaic power plants in the world continues to increase both in number and installed power. As of today, there is already an installation in India that produces 1000MW. However, even larger photovoltaic solar power plants are still being built.
In this sense, the countries that lead the production of photovoltaic solar energy are China, the United States and India.
From the main photovoltaic solar installations in the world we highlight: Kurnool Ultra Mega Solar Park. 1,000 MW. India
The Krnool Ultra Mega Solar photovoltaic park is located…
A photovoltaic solar installation connected to the network has only three basic elements:
- A group of photovoltaic solar panels. These solar panels are usually located on the roof of a building or integrated into any structural element of the same building. The photovoltaic panels can also be arranged directly on any land near the electricity grid.
- Ondulator or electronic inverter-converter. This device transforms the energy in the form of direct current provided by the solar panels, in alternating current of the same type and value as the one transported by the electric…
In the autonomous electricity supply facilities, it is necessary to store the energy captured during the hours of solar radiation in order to cover supply during the hours when there is no (daily cycle and seasonal cycle).
- Electric batteries have a very important and fundamental to the proper functioning and duration of a solar photovoltaic installation function.
- They must have sufficient capacity to ensure supply of electricity during periods of clouds (autonomy of installation).
- It is reversible electrochemical systems…
Any implementation of a sustainable photovoltaic solar energy system implies the optimization of the resources to be used. This is the basis of the design and assembly of solar installations.
To achieve optimum optimization of solar radiation, that is, the use of the Sun, it is essential to know the solar trajectory, the profile of the needs and the conditioners of the location. All this involves determining the orientation and inclination of the solar panels in fixed installations to achieve the minimum cost of the kilowatt hour of this type of renewable energy.
For reasons of…
The photovoltaic cells are responsible for converting solar radiation into electrical energy in the form of direct current. Photoelectric cells are an indispensable element for this type of renewable energy.
There are different types of photoelectric cells depending on the nature and characteristics of the materials used. The most common type is the crystalline silicon cell (Si). This material is cut into very thin disc-shaped, monocrystalline or polycrystalline sheets, depending on the manufacturing process of the silicon bar.
The first crystalline cell that was manufactured…
Low-temperature solar thermal energy is used in applications that require temperatures between 100ºC and 250ºC. From 80ºC the flat collectors practically no longer have any performance and it is necessary to resort to other capture systems.
Low-temperature thermal energy systems are used mainly for applications that demand thermal energy, that is, heat between 125º C and 400º C. To reach higher temperatures it is necessary to concentrate the solar radiation.
For this type of solar thermal energy, two types of solar collectors are used:
Biomass and biofuels is a type of renewable energy that can be used for the generation of electricity and heat. There are different applications of biofuels. The production technology of these alternative fuels allows to create different products.
The problem of the convenience of feeding with alternative fuels to those that originate from fossil oil is that, in motor fuels, all states in the world impose high taxation. However, biofuels must be considered as non-renewable energy because the generation and recovery time of the fields is lower than the consumption time.…
Alternating current (AC) is a type of electrical current that is characterized by changing over time, either in intensity or direction, at regular intervals.
The voltage varies between the maximum and minimum values cyclically, the value of the voltage is positive half the time (positive half cycle or half positive period) and negative the other half. This means that half the time the current flows in one direction, the other half in the other direction. The most common form of undulation follows a sine-type trigonometric function, since it is the most efficient and practical…
An ampere-hour is an electric charge unit. It is represented by Ah. The ampere-hour is not part of the International System, since the hour is not either.
The ampere-hour indicates the amount of electrical charge that passes through the terminals of a battery (or an electrical conductor) providing an electric current of 1 ampere (A) for one hour (h).
The ampere-hour is used to measure the capacity of a battery, ie the amount of electricity it can store during charging and return during discharge.
A battery that has, for example, a capacity of 100 Ah, theoretically can give…
In the market there are several types of photovoltaic solar panels for domestic use. The most common types are monocrystalline photovoltaic panels, polycrystalline solar panels and thin-film solar panels.
Around 90% of the photovoltaic technology is based on the use of some silicon variation. In the case of solar panels intended for domestic use, this percentage is even higher.
The main difference between the different types of photovoltaic panels is the purity of the silicon used. The purer the silicon, the better aligned its molecules are, and the better it converts solar energy…
The zero law of thermodynamics speaks of what we experience every day: two systems that are in thermal equilibrium with a third are in equilibrium with each other. It is said that two bodies are in thermal equilibrium when, on contacting each other, their state variables do not change. Around this simple idea the zero law is established.
Every law of physics has its relevance, as well as the zero law of thermodynamics, which curiously was the last of the thermodinamic laws to be introduced in literature. After the realization that heat is a form of energy that could be transformed into…
In the beginnings of photovoltaic solar energy, the electrification facilities used electricity for consumption at the same voltage and with the same form that they received from photovoltaic solar panels and accumulators, that is, at 12, 24, 48 volts in direct current. This made a big difference with the users who had electricity distribution network or generator sets at 220 volts alternating current.
The appliance market has adapted to the majority of users and we can find any appliance with 220 volts of alternating current. Therefore, getting reliable, quality, and reasonably…
A photovoltaic panel is a type of solar panel designed for the use of photovoltaic solar energy. Its function is to transform solar energy into electricity.
Photovoltaic panels can be used to generate electrical power in both domestic applications and commercial applications.
The photovoltaic modules are formed by a set of interconnected photovoltaic cells. The photovoltaic cells that make up a photovoltaic panel are embedded and protected. The photovoltaic panel is in charge of directly transforming the energy of solar radiation into electricity, in the form of direct current.…
Monocrystalline silicon is the base material for the silicon chips used in practically all current electronic equipment. In the field of solar energy, monocrystalline silicon is also used to manufacture photovoltaic cells due to its ability to absorb radiation.
Monocrystalline silicon consists of silicon in which the crystalline lattice of the entire solid is continuous, does not break at its edges and is free of any grain limit. Monocrystalline silicon can be prepared as an intrinsic semiconductor that is composed only of very pure silicon, or can be doped by the addition of other elements…
A mini-hydraulic power plant is a power plant that uses hydropower for the production of electricity. They are characterized by the fact of having a reduced installed power. Its small size implies the use of structures of much smaller size than a normal dam. These mini-hydraulic plants are safer, thanks to the smaller volume of water in the basin, and which also have a lower environmental impact and landscape.
There is no globally accepted limit for which a hydroelectric plant is defined as mini-hydraulic. According to the ESHA (European Association of Small Hydroelectric Power Plants),…
A steam turbine is a device that is used to convert the high pressure of the steam into the rotation of an axis that provides power output (shaft). This type of turbine is mainly used in power plants (for example, in high temperature solar thermal power plants), but also in other applications where large capacities are required, such as offshore vessels.
With a modern steam turbine, the steam is guided against a row of rotor blades, which changes the steam direction as much as possible. Then, the steam passes through a row of stator blades, where it again rotates from the direction…
What is silicon?
Silicon is a chemical element of atomic number 14 and symbol Si. This chemical element belongs to group IV A of the periodic table. JJ Berzelius 1824 isolated it by reduction with potassium of silicon tetrafluoride (SiF4).
The crystalline elemental silicon is grayish in color with a metallic luster, very hard, with very high melting and boiling points, and is an intrinsic semiconductor. The amorphous form of the element occurs in brown powders, conductive of electricity, which can be easily melted and vaporized.…
A photon is the quantum of energy in the form of electromagnetic radiation, emitted or absorbed by matter.
A photon is an elementary particle, the quantum of all forms of electromagnetic radiation, including light. It is the particle mediating the electromagnetic force, even when it is static through virtual photons.
The photon has zero mass at rest and consequently the interactions of this fundamental force are observable at both microscopic and macroscopic scale.
Like all elementary particles, photons are explained by quantum mechanics but exhibit wave-particle duality,…
Petroleum is a complex non-homogeneous mixture of hydrocarbons, composed / formed by hydrogen and carbon. The kinds of petroleums are very different from each other, can be from yellow and liquid to black and viscous. These differences are due to the relationships between the types of hydrocarbons. It is a non-renewable natural resource, raw material for numerous materials and products and, as a fossil fuel, the main primary energy source in the world.
The chemical components of petroleum are separated and obtained by distillation through a refinery process. From it different products…
Although in principle it seems that in an installation of photovoltaic solar energy just need solar modules and batteries, there is a key element in these facilities is what ensures that, in the charging process as in the discharge accumulators, is made so that they are always within the correct operating conditions: the charge controller.
Solar panels are designed so that they can give a higher than the end voltage battery charging voltage. This ensures that the solar panels are always able to charge the battery, even when the temperature of…
The direct current is a type of electric current very important in solar energy where the direction of flow of electric charges (electrons) does not vary. In many devices the symbol to indicate direct current is DC (direct current), or using the symbol of a continuous line (-) flanked by three shorter lines (---), for the alternating current that is used instead of AC (alternating current) or the symbol (~).
The flow of charges occurs through a conductor, such as a metallic thread. The flow could also be established through a semiconductor, an insulator or even vacuum as in a cathode…
The balance of system (also known by the acronym BOS) includes all the components of a photovoltaic system with the exception of photovoltaic panels. The balance of system is constituted, typically, by the electrochemical accumulator in the case of some isolated systems of the network, the control unit and the inverter (electronic equipment), the mechanical support structure, the electrical wiring and the protection devices (fuses, ground connections and switches).
Other optional components in a solar BOS include, maximum power point monitoring (MPPT), GPS solar tracker, energy…
The charge controller is a separate element of the autonomous photovoltaic systems. It is also known as charge controller.
Being an installation in which the energy generated by the photovoltaic modules is not supplied directly to the mains will be needed batteries.
To charge batteries safely charge controllers play a key role in both the loading and discharge the battery.
The charge controller is limiting the energy that is supplied to the battery and when the battery is charged, if he continues to supply energy, become hot and could create a dangerous situation.
These installations are mainly used in locations where there is no access to the electricity grid and it is more economical to install a photovoltaic system than to lay a line between the grid and the point of consumption. The electricity generated is intended for self consumption.
The main applications of isolated systems are:
- Electrification of houses and buildings, mainly for lighting and low-power appliances
- Street lighting
- Agricultural and livestock applications
- Water Pumping and Treatment
- Telephony antennas isolated from the network…
Thermodynamics is the branch of physics that studies the effects of changes in temperature, pressure and volume of a physical system (a material, a liquid, a set of bodies, etc.), at a macroscopic level. The term "thermo" means heat and dynamics refers to motion, so thermodynamics studies the movement of heat in a body. Matter is composed of different particles that move disorderly. Thermodynamics studies this disorderly movement.
The practical importance of thermodynamics lies primarily in the diversity of physical phenomena it describes. Knowledge of this diversity has resulted in…
We have two definitions of electricity depending on whether ns refer to physical phenomena on a macroscopic scale or on a microscopic scale.
With the term electricity we refer generically to all physical phenomena in a macroscopic scale that involves one of the fundamental interactions, the electromagnetic force, with particular reference to electrostatics. At the microscopic level, these phenomena are due to the interaction between charged particles on a molecular scale: the protons in the nucleus of atoms or ionized molecules and the electrons. The typical macroscopic effects of such…
A solar collector of evacuated tubes is a type of solar panel that uses solar thermal energy. The finality of solar collectors is converting solar radioation into thermal energy.
This renewable solar energy system uses a type of solar panel consisting of linear collectors housed in evacuated glass tubes.
The evacuated tube solar collector consists of a set of cylindrical tubes. The tubes are formed by a selective absorber, located on a reflector settlement and surrounded by a transparent glass cylinder.
The vacuum has been made between the transparent outer tube and…
A hydroelectric power plant is a set of hydraulic engineering working located in a certain succession, together with a series of suitable machines. The objective of a hydroelectric power plant is to obtain electricity from the potential energy of moving bodies of water. This is what is called hydropower.
The energy produced by hydroelectric plants must be classified in all aspects as renewable energy because, at least in theory, water can be reused endlessly for the same purpose without undergoing a purification process. The concept of renewability is subordinated to the constancy of…
An adiabatic process is a thermodynamic process in which the system does not exchange heat with its surroundings. An adiabatic process may also be isentropic, which means that the process may be reversible.
The adiabatic process provides a rigorous conceptual basis for the theory used to expose the first law of thermodynamics and, as such, is a key concept in thermodynamics.
The term adiabatic refers to elements that impede the transfer of heat with the environment. An isolated wall is quite close to an adiabatic limit. Hence the adiabatic wall term appears.
A process that…