While
the word ‘solar’ comes from the word ‘sun’, the energy
part of it comes from renewable source that can never be
exhausted as along as the world’s greatest powerhouse
remains alive. Solar energy
involves the technology of obtaining usable energy from
the light of the sun. Solar energy has been used in many
traditional technologies although it is very recently
that we have been able to harness it to our benefit.
Solar energy is currently utilized for generating
thermal or heat energy and for generating
electricity.
As
for generating electricity, solar energy is
utilized in two key methods, namely, by Photovoltaic (PV
devices) popularly called ‘Solar Cells’ and Solar Power
Plants that generate electricity by ‘indirect’ means.
Photovoltaic or PV devices are generally used in remote
village areas or isolated pockets of population that are
not connected to power grids as also in smaller forms
for powering pocket calculators, wrist watches and
illuminated emergency road signs. But now, this
alternative energy is being used in urban homes and at
commercial establishments as well.
To
understand how photovoltaic cells transform rays of the
sun into electric current, it may be necessary to enter
into the details of the process. When the photons
derived from the sunlight strike a solar cell, some of
it goes away, reflected by its surface but some also get
absorbed within it. These absorbed protons provide
energy to generate electricity. When sufficient sunlight
is absorbed by the semiconductor, i.e. the silicone
material, electrons from the material’s atoms get
dislodged. As the especially designed frontal surface of
the material is more receptive to the free electrons,
they migrate to the surface.
When
too many electrons, each carrying a negative charge
starts traveling towards the frontal surface, the
resultant
imbalance of charge between the silicone’s front
and rear creates a voltage potential similar to the
negative and positive terminals of a battery. If at that
point of time these two are connected through an
external load, electricity flows through them. The PV or
Photovoltaic cell therefore, is the basic building block
of a PV system. Though individual cell varies in
dimension from 1 cm or .5” to around 10 cm or 4”, they
can at best produce only a watt or two of electricity
which is much too less for any application. To get more
power output, several electrically connected cells are
made into packaged weather-proof modules. When several
such modules are connected to form an array, the desired
power output can be obtained.
This
alternative energy may be what will save us in the
future. The fossil fuel reserve is fact depleting and
one day soon we have to depend on such sources solely.
Solar power is clean too and this is great news. Solar
power also saves money on electricity bills and this is
why it is great for the masses. If you want to go for
solar power, you need to know a few things like where
you should put up the system and how to complete the
wiring and the installation. You will also have to know
about the sources of finding cheap batteries and parts
and also the safety precautions. Get a guide that will
tell you about all this.
