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.
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…
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…
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…
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.…
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…
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…
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.
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.
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…
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,…
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…
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…
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…
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…
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…
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…
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…
These equipments have a natural circulation based on convection currents formed in the fluid at different temperatures.
If we heat a water tank at the bottom when the bottom water warms, it becomes less dense and rises to the surface where it cools. Then returns to the bottom of the container and thus a natural circulation flow is generated.
This is the operating principle of a thermosiphon team, which will be essential that:
- The solar collector (heat sources) is always located below the level of the accumulator.
- The primary circuit is as short as possible…
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 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…
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…
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…
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…
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…
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 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 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,…
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…
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…
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 and increases its recovery rate.
Hydraulic fractures in rocks can be both natural and created by humans; they are created and enlarged by the pressure of the fluid…
The volt is the international system unit measures for measuring electromotive force and voltage.
The volt is represented by the symbol V. The measuring instrument for measuring voltage is the voltmeter.
Two different definitions of volt can be given:
On the one hand, we can consider that a volt is the voltage between two points of a conductor through which passes a current of one ampere (A) and a power of one watt (W) is dissipated.
Another alternative way to define it: The volt is equivalent to the potential difference that exists between two points of a conductor…
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.…
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…
The Kelvin is the temperature unit of the International System. The Kelvin is one of the seven basic units of temperature. Its symbol in the international system of units is K. The Kelvin scale is a thermodynamic (absolute) temperature scale where the absolute zero, the theoretical absence of energy, is zero (0 K). This unit is named after the British physicist, mathematician and engineer William Thomson (1824 - 1907), who was later named Lord Kelvin. Lord Kelvin wrote about the need for a "thermodynamic temperature scale".
To express the temperature difference or the interval, the use…
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…
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…
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 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 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…
The degree Celsius (in symbol in ° C), is the unit of a temperature measurement scale, named after the Swedish astronomer Anders Celsius (1701 - 1744), who proposed it for the first time in 1742.
The Celsius scale fixes the melting point of ice in a mixture of water saturated with air at 0 ° C and boiling point at 99.974 ° C under standard pressure conditions (1 bar, a little less than one atmosphere, pressure in the that the water boils at 100 degrees Celsius).
Originally conceived by the scale Celsius had the boiling point of water at 0 ° C, and the freezing…
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…
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…
In thermodynamics, an isobaric process is a change in the state of a certain amount of matter in which the pressure does not change, but one or more of its state variables. An example of this is air in a cylinder with a freely movable piston to which heat is supplied. Due to the increase in temperature, the volume will increase, but the pressure will remain constant.
The isobaric process is governed by Charles's law. The Frenchman Jacques A. Charles (1742-1822) was the first to make measurements about gases that expand when their temperature increases. Examples of isobaric processes…
The Fahrenheit degree (° F) is a temperature unit proposed by Gabriel Fahrenheit in 1724.
On the Fahrenheit scale, the melting point of water is 32 degrees of temperature, and the boiling point is 212 degrees. A difference of 1.8 degrees Fahrenheit equals that of 1 degree Celsius. Fahrenheit established the zero temperature (0 ° F), the freezing point of a 50% mixture of salt (ammonium chloride) and ice, and as 96 ° F, he took the temperature of the blood (he used that of the horses ). The figure 96 may seem an odd measure, but in principle the scale contained only twelve…
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…
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…
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…
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 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.
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…
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…
In chemistry, the term electrolyte refers generically to substances that in solution or in the molten state undergo subdivision into ions of their molecules. Substances that do not dissociate are called non-electrolytes.
The term "electrolyte" refers to the ability to conduct electricity through the intervention of ions, a peculiar characteristic of these chemical species. Therefore, an electrolyte constitutes what is called an ionic conductor or, alternatively, a conductor of a second species. Electrolytes are capable of conducting the electric current, once dissolved in solution, precisely…
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…
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,…
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…