Solar energy is the energy obtained by capturing the light and heat emitted by the sun. It can be harnessed through the heat it produces, as well as through the absorption of radiation. It is part of the compendium of energies.
Like wind energy, there are uncontrollable variables that will affect the performance of these plants, which work according to the solar radiation that exists: the time of day, atmospheric conditions, and latitude. Therefore, the irradiance (the radiation that falls over a period on a given surface) will be different depending on these variables.
WAYS TO USE SOLAR ENERGY
It should be noted that there are several ways of harnessing solar energy to transform it into electricity. As indicated in the introduction, it can be harnessed through heat or radiation absorption.
INDIRECT METHOD
This is the one that uses the heat from solar energy to generate electricity. What is done is to heat a fluid to transform it into steam, so that it can move an alternator to produce electricity. This is generated through what is known as a thermodynamic cycle.
The typical structures of this type of solar energy utilization method are solar thermal power plants. They consist of an area in which a number of mirrors (heliostats) are located to reflect the solar radiation towards a boiler located in the main tower. This boiler contains fluid that is heated by the radiation incident by the heliostats. Once heated, as mentioned above, the steam will be directed to the generator to transform the thermal energy into direct current electricity, which through a transformer will become alternating current, thus being incorporated into the power grid.
This type of installation has fluid storage tanks, as well as a boiler and a steam engine so that, during periods when there is not enough solar energy, or at night, the plant can continue to operate.
DIRECT METHOD
This is the method in which sunlight is harnessed to convert it into electricity using solar cells. Photovoltaic installations use this method. This happens thanks to the Photovoltaic Effect, in which the photons, when falling on these cells, and being absorbed by them, the energy brought by such photons is transferred to an electron of an atom of the solar cell. This energy allows the electron to escape from the atom to form a current in an electric circuit.
PHOTOVOLTAIC INSTALLATIONS
Before going into the operating mode of a solar panel, it is worth knowing what types of photovoltaic installations exist.
AUTONOMUS PHOTOVOLTAIC INSTALLATIONS
They are those that do not have a connection to the electrical distribution network. Their purpose is to provide electricity directly to areas where it is very difficult, or impossible, to connect them to the power grid. They include the following:
Space applications: They are intended to provide electricity to objects placed by humans in space.
Terrestrial applications:
- Telecommunications
- Electrification of rural and isolated areas
- Signaling
- Street lighting
- Water pumping
GRID-CONNECTED PHOTOVOLTAIC INSTALLATIONS
The purpose of these is not to directly supply electricity to a specific area, but rather to sell it to the electricity grid manager of the area or country. There are two types of these:
Photovoltaic power plants or solar farms
These are enclosures where a certain number of these photovoltaic installations are concentrated and belong to different owners. They sell the electricity generated to the electric company with which they have a distribution agreement.
Photovoltaic buildings
They mix architectural aesthetics and sustainable development. The idea is to install photovoltaic panels on the facades of buildings, where the electricity generated is sold to the electricity distribution company.
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