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…
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…
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…
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…
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 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…
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…
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.…
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…
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…
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…
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…
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…
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,…
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…
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 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…
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.…
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.
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…
A thermodynamic state is a set of values of properties of a thermodynamic system that must be specified in order to reproduce the system. The individual parameters are known as state variables, state parameters or thermodynamic variables.
When a sufficient set of thermodynamic variables has been specified, the values of all the other properties of the system are unambiguously defined. The number of values needed to specify the state depends on the system, and is not always known. Status functions
The state functions describe the momentary condition…
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,…
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…
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…
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…
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…
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.
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…
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…
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…