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…
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…
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…
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…
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.
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.
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…
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…
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…
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 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 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 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 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…
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.…
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…
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…
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.