Historical context and evolution.
Throughout the history, our star king the Sun has been an important element
in the evolution and development of life from the Mesopotamians to our days. The
ancient primitives harnessed the energy coming from the Sun, without having any
knowledge, as we know today.
Some civilizations like the Egyptians venerated the Sun, attributing to him
a god given its importance, Ra. The Romans used the energy of the sun to heat
their homes by storing the heat in the windows.
Others have contributed in an important way, taking the benefits that our
star brings. Some of them are:
Archimedes developed mirrors to concentrate solar radiation at one point,
and thus be able to eliminate enemy ships. This idea, continued to be used in
later centuries in the burning of trees and metal smelting.
Lavoisier in 1972, designed and manufactured the solar furnace, which
consisted of two lenses that concentrated all the energy coming from the Sun in
one focus, allowing to reach high temperatures for metal casting.
In 1874 Charles Wilson designed and directed an installation for the
distillation of marine water in the Atacama Desert, which allowed to desalinate
a capacity of 22.500 liters daily.
But, some of these historical characters went further into the study of
solar energy. Its motivation was based on the development of energy generation
to reduce energy consumption due to population growth.
In 1838, Alexandre Edmond Becquerel was the first in discovering the
photovoltaic effect when practicing with his electrolyte battery, he realized
that by exposing it directly to the Sun, the current was increasing.
In 1953, Calvin Fuller, Gerald Pearson and Darix Chapin discovered the
solar cell of Silicon (Si), which will be important in the future of the
history of solar energy.
These small advances led to the initiation of solar photovoltaic energy,
although their use decreased due to the low cost of fossil fuels and the
increased use of nonrenewable energies.
Resurfaces in the 1970s due to the increase in fuel prices. But, really, it
radically changed in the early 1990s with the Gulf War.
Types of solar energy and
applications.
As the human has been discovered great applications with the use of solar
energy, it has been classified with the criterion of its use by transformations
(active solar energy) or directly (passive solar energy).
- Within the active solar energy, we can differentiate between solar photovoltaics (the one that we can transform by solar panels, the direct current of the sun into alternating current for the network). And solar thermal (that takes advantage of the water heating to generate steam and generate electricity by the movement of turbines).
Some applications of the use of solar energy, focus on generating
electricity, but it is used not only for this purpose, but also for water
heaters, for night lighting through the accumulation of daytime energy, and
although it is planned for the use of transport. The most common
instrument is the installation of solar panels for the home, to save on the
light bill.
Solar panels are
composed by numerous cells (photovoltaic cells) of crystalline silicon or
gallium arsenide, semiconductor materials. When photons from sunlight
strike these cells, some are absorbed by such material. These generate a
movement of charges through the semiconductor generating electricity (an electrical
circuit).
To use this direct current to our electronic devices, an inverter is
necessary to transform the direct current to alternating one.
There are issues that are taken into account in its application, so it is
necessary to keep in mind the advantages and disadvantages of solar energy.
These are:
Advantages:
• It is a type of clean energy
• It is an energy that comes from an almost inexhaustible source, due to the long duration of its life.
• It is one of the most economical renewable energies available.
• It is an independent energy, because it reaches all parts of the world, against the tidal wave.
• Easy Maintenance.
• It is an energy that comes from an almost inexhaustible source, due to the long duration of its life.
• It is one of the most economical renewable energies available.
• It is an independent energy, because it reaches all parts of the world, against the tidal wave.
• Easy Maintenance.
Disadvantages:
• In order to supply this type of energy, it is
necessary large areas to carry out such installation of panels.
Need hours of sunlight. There are countries where
implantation would not be effective due to the few hours of sunlight.
• The manufacture of photovoltaic cells requires the need for polluting energies. (Not Renewable)
• The manufacture of photovoltaic cells requires the need for polluting energies. (Not Renewable)
In the not too distant future solar energy is expected to be competitive
with energies called pollutants. But in order to do this, we must continue to
rely on study and development in this field with all the means, since it is a
free and clean source. There will be drawbacks such as fluctuations in solar
radiation due to stations, usage policies, etc. But, as a result, we will be
able to live on a cleaner planet and without the need to exhaust the resources
it provides.
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